10watts for all 4, will it work  - Page 1
Forum section: electronics / beginners

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 05, 2017, 10:41:53 am
content: As making basic EI transformer inverter is super easy i am planning a thingi am adding a triac based switcher to make sure the apparent LED load is within 10W in the inverterso a bulb is made on at a time and fast switch is done so that every bulb look steady glow but inveter can be used is very low wattExperts please suggest will it work ?clarification :::It is not a DIMMERit is NOT a XMAS lightI dont want to use 12V LEDjust DIY $5inverter should be able to do double duty that is 10W inverter drives 20W

author: Zero999
author_rank: Super Contributor
timestamp: November 05, 2017, 10:54:13 am
content: This seems like a bad idea.Why not simply use 12V LEDs?The AC is only converted back to DC inside the LEDs anyway, so it makes sense to use LEDs rated to the correct voltage in the first place.

author: Twoflower
author_rank: Frequent Contributor
timestamp: November 05, 2017, 11:03:29 am
content: I'm not sure if I understand your plan correct: You try to sequentially power one bulb or probably two at the time, switch to the next and so on. Is my assumption correct?In that case you'll probably run into problems. As the high voltage (110V/230V) LED bulbs contain some circuit that could behave funny if it receive the supply in bursts. It could even shorten the lifetime as the primary capacitor in there will be under additional stress. But again this depends on the circuit in the bulbs. Cheaper ones might survive that better but probably flicker a lot (the ones with no build-in switching circuit).As alternative: Have you thought to skip the inverter and use 12V DC LED bulbs? They might behave better if driven from a PWM source. Or better use LED bulbs that don't need to be dimmed down at all. As side effect: This will have a higher efficiency as you don't to the surplus converting to the high voltage and back down (within the LED bulbs).

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 05, 2017, 11:29:55 am
content: i am making a box inverter and user can use any LED bulb . not a emergency light .. wire length they can use higherthat makes it more suitable also 12v DC bulb is vv rare

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 05, 2017, 11:35:30 am
content: Quote from: Twoflower on November 05, 2017, 11:03:29 am12v bulbs not a option longer cables will be used to put ,say 2 story building .I have used 220V LED bulbs for very longtime on almost square wave inverters bulbs dont care of that .Keeping inverter cost low is main needed , efficiency is not that of concern as similar inverter running with loong 12hr backup( not having Triac switcher)

author: wraper
author_rank: Unknown
timestamp: November 05, 2017, 12:35:25 pm
content: You certainly cannot do this. And if you use normal quality LED bulbs which include driver circuit, you won't even decrease power consumption. They will just charge internal capacitor with much higher current in the moment power is applied. Thus reducing it's lifespan. If you need to decrease power consumption, use lower power LED bulbs.

author: orolo
author_rank: Frequent Contributor
timestamp: November 05, 2017, 12:51:29 pm
content: Big Clive wonderfully explains the problem with triac dimming and LED lights in this video.

author: Zero999
author_rank: Super Contributor
timestamp: November 05, 2017, 03:59:20 pm
content: Quote from: wraper on November 05, 2017, 12:35:25 pmI agree. Another issue is with using a square or modified sine wave, a capacitive ballast, used in many LEDs, the current will be much higher, than the design value, causing unreliability, possibly smoke and fire.

author: jeroen79
author_rank: Frequent Contributor
timestamp: November 05, 2017, 04:56:53 pm
content: I don't get what this TRIAC switcher is supposed to do.Is it just a dimmer?If you're starting with 12V DC then converting to AC seems inefficient to me.Look for suitable 12V leds instead.

author: Zero999
author_rank: Super Contributor
timestamp: November 05, 2017, 05:52:29 pm
content: Quote from: dave_j_fan on November 05, 2017, 11:35:30 amWhy not? At lower voltages, the current required for a certain amount of power, will need to be higher, but it's only 10W, which is under an Amp at 12V, so the cable doesn't need to be very thick. If the maximum voltage drop is 1V, at 1A, then maximum cable resistance is 1Ohm. 1mm2cable has a resistance of 18.1mOhm/meter, so the cable can be as long as 1/0.0181 = 55.25m, or 27.6m as two wires will be used: one for the positive and anoter negative.https://www.tlc-direct.co.uk/Book/5.3.6.htm

author: Twoflower
author_rank: Frequent Contributor
timestamp: November 05, 2017, 06:04:31 pm
content: OK, Hero999 beat me with the post by a few minutes. But I'll post it anywayThe statement "about the higher drop because using 12V compared to 230V" doesn't really count for such low loads. Your schematics show a 10W inverter to 4 bulbs. That allows max. 2.5W per bulb. At 12V this is 210mA. Assuming a 50m (actually 2x50 as you have the return wire as well) wire with 1mm^2 has about 1.7Ohm. That means you loss at the wire is less than 74mW.Of course if you want them to 'glow' dimly you can probably drive the LEDS with even lower power and the cable losses will go down a lot. At 1W the losses are already down to 12mW as the current appears squared (P = I^2 · R).If all bulbs are 50m away that sums up to 300mW. Please tell me that your self build inverter has lower losses than 300mW or better than 97% efficiency. Which would be extremely well for a 12V to 230V inverter, you could make money with the design.Edit: Changed calculations from 5 to 4 Bulbs..

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 07, 2017, 10:37:50 am
content: it is not a design challenge ,,,purpose is to deliver low cost inveter for small shop and students12v dc wireloss make unsuitable for little longer lenths of wire where two bulbs will light up ;like a poor mans housethen u may ask why not make 80watt inverter ?this his cost bench mark and needs bulk batteryeven if loss is low 12V leds are vry rare to find , and during gridpower they need 12V SMPS to run adding to inverter cost(inverter auto switch)

author: Zero999
author_rank: Super Contributor
timestamp: November 07, 2017, 02:04:43 pm
content: Quote from: dave_j_fan on November 07, 2017, 10:37:50 amWhat's the maximum wire length?As we already stated, the loss in an inverter will exceed that of a 27.6m, 1mm2cable, at 12V 1A, which is over 91% effient.And as 12V LED bulbs are widely available. I suggest MR16 / GU5.3 lamps. I've recently purchased some for my parent's and sister's house. They've very efficient and run cool, compared to the halogen lamps they're designed to replace.Another option is using a higher DC voltage, such as 24V or more, but I haven't looked into the availability of such LED lamps.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 08, 2017, 06:00:41 am
content: i request all to see the scenario that all bulbs are not available all parts of world. even 12v ones of substandard quality in many partsif the 12v bulb topic is pulled again i will have to walk off .if somone can highlight 230v switching plan that is running on off at very fast rate like 1Khz please sharerunning 12v LED , i dont want to do , the reasons already stated ...... please reply on 230v led only

author: Zero999
author_rank: Super Contributor
timestamp: November 08, 2017, 09:16:01 am
content: Why not buy an off the shelf 230V inverter? It will be much cheaper than making one.https://m.ebay.in/itm/3-LED-STRIP-SMD-WATERPROOF-LIGHT-MODULE-5050-WARM-WHITE-DC-12V-FOR-CAR-BIKE-/181612437698?hash=Ng==The LEDs can then be switched using plain old mechanical relays.EDIT:Sorry missed this:QuoteWhy do you want to do that? Do you want to dim the LED? If so, that's not feasible with 230V 50Hz.Why not use a dimmable LED? If so you'll most likely need a pure sine wave inverter.Another option is several lower powered LEDs and a circuit to control how many are switched on.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 08, 2017, 09:29:04 am
content: Hero999,post 0 has all details . Why all are serving 12VLEDfor the the ones who dont read post 0- It is NOT a tip top light-it is NOT dimmer-YES its is SOMTHING else" it is to switch load very fast so that 10W inverter driver 20watts LED "i hope no 12v LED suggestions will come

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 08, 2017, 09:33:15 am
content: my inverter is $5 inverter compact , "DIy"and 10watts capacitycan it drive 4 of the 5watts LED

author: Zero999
author_rank: Super Contributor
timestamp: November 08, 2017, 10:00:18 am
content: Quote from: dave_j_fan on November 08, 2017, 09:29:04 amI posted the wrong link:https://m.ebay.in/itm/150-Watt-Inverter-12V-to-220V-DC-to-AC-Converter-Board-For-Home-Car-Solar-DIY-/282609533548?hash=NA==QuoteDon't be so childish! You don't make the rules here. People are free to suggest what they like. If you don't like it, you're free to ignore it.QuoteBad idea. It wont work. If you can't get a larger inverter, you need lower power LEDs.Quote from: dave_j_fan on November 08, 2017, 09:33:15 amNo, that would overload it, causing it to overheat or some protection circuit to kick in.If you've made the inverter yourself, then why not post the schematic and a picture so we can suggest how to increase the power rating to 20W?

author: Twoflower
author_rank: Frequent Contributor
timestamp: November 08, 2017, 07:26:31 pm
content: As many times said: Will it work? --> Probably not.And as this was said we tried to provide you alternative solutions which in general, but not for every case, is superior to your solution. And as we don't know your specific problem we just provided a solution that works in general. If you're not happy with this, you should provide more input to work with. Or take the short answer to your question in the subject line: Probably not.Switching the different lanes at high speed might have a negative impact at a) The losses on the cables and b) emit electro magetic noise.As this was noted here: Your results might be unpredictable. As there are different ways to implement 230V LED bulbs. From 'put as many LEDs in series plus a small resistor' to a full blown SMPS. If the LED bulbs contain a SMPS which might not behave as you hope. The input capacitor will have a high inrush current which might exceed the rated 5W of a LED lamp in operating mode. If you switch off and on the supply the high inrush current will probably repeat. If you use the 'simple' ones they might start to flicker annoyingly.And something you should consider while implementing your inverter: Be aware that some LED bulbs might require a frequency close to 50 or 60Hz. If the bulbs use a capacitor to reduce the line voltage that could fry the bulbs easily.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 08, 2017, 09:59:59 pm
content: I thought why not make the jig ...The bulb fry myth has been busted , i was able to reach a steady glowthe SCR based sequencer works beautifully!All 4 channels are active ... but SCR and bulb is on one channeli will add 3 more SCR and bulbs .testing with 4w PHILIPS bulb on 230V ACI have been using SMPS LED lamps , they seem to respond well to few Khz frequencyall shops and places use squarelike inverters with higher switching freq. the bulbs are doing just fine.(may reduce 1year life, but thats ok of the avg life is say 4 year , reducing to 3year is unnoticable)However , i have delivered all inverters to poor and needy. I will make one 10watterand check if its driving well .But i appreciate the know how shared so far

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 08, 2017, 10:12:38 pm
content: Hero999,buying 150w inverter not an option ..most of these are china clones cant be sure of reliability .the higher watt inverters waste more watts if the load is 10-20w .when Qn is : can i drive 20w load on 10w with sequencerAnswer cannot be make 20w inverteri can make even 100watts one ... but cost and needed battery will make it unusable for the masses .next is regrding posting my inverter scheme.. thats design trademarkits is $5pack with charger and inverter and autoon combo... with battery protection circuits

author: Zero999
author_rank: Super Contributor
timestamp: November 09, 2017, 09:43:40 am
content: Quote from: dave_j_fan on November 08, 2017, 09:59:59 pmYes, you need an LED with a switched mode power supply. There will be a limit to the maximum frequency of the supply voltage, because the bridge rectifier on the input stage will gradually become less efficient, as the frequency increases. Running on 200V to 300V DC is another possibility.Quote from: dave_j_fan on November 08, 2017, 10:12:38 pmIf you designed the inverter, then you should know whether it can power a 20W LED or not, so why are you asking that question here? There's no point in keeping the schematic for your inverter secret. There are 100s of schematics for inverters, which can be found on the Internet and many people here are capable of designing one from scratch.Or is the question not about the inverter, but the sequencer? Can you post a schematic for that or is it a secret too?

author: mikerj
author_rank: Super Contributor
timestamp: November 09, 2017, 11:05:04 am
content: I am at a total loss to understand the point of this. Rather than trying to dim a 10W lamp so it only consumes 2.5W, why not start with a 2.5W lamp?How are you intending to switching a TRIAC on/off at a frequency greater than the zero crossings of the 50/60Hz line frequency?

author: Zero999
author_rank: Super Contributor
timestamp: November 09, 2017, 01:50:58 pm
content: Quote from: mikerj on November 09, 2017, 11:05:04 amPerhaps the inverter generates a higher frequency than the normal mains?

author: ogden
author_rank: Super Contributor
timestamp: November 09, 2017, 03:30:53 pm
content: I would like to disagree to most of the LED bulb horror stories told here and ask everybody to think how it could work, not how it can fail. - Because after all original poster is doing good job - he is trying to make our world better place.My two cents: 10W power is so low that I would not bother about sequential switching, any LED switching at all. I would run all the LED bulbs in parallel - to save on wiring in many installations and create10W PWM-dimmable AC square wave inverter with input current limiter. Current limiter as safeguard against inverter overload and output short. Also it is worth to consider optional frequency control in 50-400Hz(?) range. Maybe it can help with some (too smart or too dumb) LED bulbs or reduce flicker. What's more or less clear here - lot of testing with various LED bulbs needed.

author: Zero999
author_rank: Super Contributor
timestamp: November 09, 2017, 04:46:59 pm
content: Quote from: ogden on November 09, 2017, 03:30:53 pmReducing the duty cycle using PWM might not work. If the DC:DC converter inside the LED has a smoothing capacitor, it'll take large current spikes on the rising edge of the pulse, with the magnitude and length of the pulse, depending on the impedance and the voltage on the capacitor. If the output of the internal DC:DC converter is constant current, then the power consumption of the LED will not change, until the PWM drops below a point. This might put extra stress on the lamp, leading to premature failure.If the LED's DC:DC converter has no filter capacitor, then it will probably work, but it will flicker at double the mains frequency, unless the inverter works at a high frequency.How do you propose PWMing the AC? It's not possible to do it in increments of less than double the mains frequency with SCRs. Another option is to use two MOSFETs back-to-back and chop the entire AC waveform at a much higher frequency, but that can lead to issues with RF interference and high surge currents, as mentioned above.Phase control is an other option, in which case leading edge should be used with LEDs, rather than trailing edge, but again MOSFETs need to be used, rather than SCRs.

author: ogden
author_rank: Super Contributor
timestamp: November 09, 2017, 06:12:31 pm
content: > Reducing the duty cycle using PWM might not work.My guess that it shall work with dimmable LED bulbs.> If the output of the internal DC:DC converter is constant currentI would like to see any <= 10W low-end LED bulb (where OP is aiming at) which have constant current converter inside. Again we CAN find particular LED's which will not work with such approach, BUT again - we shall use common sense here too.> This might put extra stress on the lamp, leading to premature failure.10W total power, 2.5W for each bulb. Again I would like to see - does LED bulbs really fail. After all hard edges can be easily filtered on the inverter output at let's say 1KHz cutoff freq or so.> but it will flicker at double the mains frequency, unless the inverter works at a high frequency.Didn't I say about 50..400 Hz frequency control which could reduce flicker?> How do you propose PWMing the AC? It's not possible to do it in increments of less than double the mains frequency with SCRs.I did say "I would not bother about sequential switching, any LED switching at all". My proposal is to PWM-controlinverter.> Another option is to use two MOSFETs back-to-back and chop the entire AC waveform at a much higher frequencyToo complex. Better chop inverter at higher frequency - as I proposed initially.> Phase control is an other option, in which case leading edge should be used with LEDs, rather than trailing edgeSquare wave inverter cannot have any leading or trailing edge phase control because it'ssquare wave. Just looked at available PW controllers. UCC28089 looks like good choice. Additional op-amp and potentiometer needed to augment current sense for PWM-control.

author: ogden
author_rank: Super Contributor
timestamp: November 09, 2017, 06:31:57 pm
content: Quote from: ogden on November 09, 2017, 06:12:31 pmObviously alternative option is digitally controlled inverter. Attiny24 is good enough for the job, especially considering it's 20x gain amplifier for ADC which is perfect match for current sense measurement.

author: Zero999
author_rank: Super Contributor
timestamp: November 09, 2017, 06:52:17 pm
content: Quote from: ogden on November 09, 2017, 06:12:31 pmThat depends on the bulb. Some dimmable LED bulbs look at the incoming waveform and adjust the LED current according.QuotePlenty, just look up LED driver ICs, using a search engine. Here's one example. Many more exist.http://www.mouser.com/ds/2/302/SSL21082AT-843512.pdfQuotePossibly. It would certainly exceed the ripple rating of the input capacitor. Another issue is, if the LED bulbs are in standard fittings, people might replace them with other LEDs which aren't compatible. Look up capacative dropper LED, which certainly will fry if operated from too higher frequency.QuoteGood idea.QuoteThe trouble is, he's already has the inverter and doesn't seem to be willing to redesign it or accept any help with the circuit, as he won't post it because it's proprietary information.QuoteThe only option if changing the inverter is not an option.QuoteActually, if could work, irrespective of the waveform, just delay the turn on, afterQuoteGood, if you're redesing the inverter.

author: ogden
author_rank: Super Contributor
timestamp: November 09, 2017, 07:54:34 pm
content: >Plenty, just look up LED driver ICs, using a search engine. Here's one example. Many more exist.>http://www.mouser.com/ds/2/302/SSL21082AT-843512.pdfExistence of drivers does not prove that they are used in low end LED bulbs. You can more or less count on that. BTW you are showing one which for sure will work with "PWM dimmable square wave inverter">Possibly. It would certainly exceed the ripple rating of the input capacitor.Ripple rating of the input capacitor?BS. This lesson comes from bigclive LED academy?Crude LED bulbs have that poor series resistor for exactly that reason. - To reduce EMI and obviously ripple  current spike when minimum forward voltage of LED string is reached (check IV curve of the led). Most "dumb" LED bulbs conduct quite late in the AC cycle. Also we shall take in account that peak voltage of square wave inverter will be just 0.7x of AC mains peak for same RMS voltage output, so current spike difference could be minimal. In short - don't bother about wearing out capacitor or series resistor.>Look up capacative dropper LED, which certainly will fry if operated from too higher frequency.I would not be so certain. 400Hz is not that high frequency after all. Also remember about power budget we are talking here about. Most likely everything will be underpowered and very far from frying.>The only option if changing the inverter is not an option.Then somebody else will save the world

author: orolo
author_rank: Frequent Contributor
timestamp: November 09, 2017, 08:23:57 pm
content: Quote from: ogden on November 09, 2017, 07:54:34 pmNot high frequency at all. Take this cheap "3W" dropper bulb from Big Clive's Academy:At 50Hz, the impedance of the 820nF is 3882 Ohms, so the RMS current is 52.5mA, and the 30V LED string dissipates a puny 1.6W, certainly underpowered for an alleged 3W bulb. Now crank the frequency up to 400Hz. The impedance is 485 Ohms, the current 359mA, and the power 10.68Watts. Ax106.6x increase in power, and 3.3x more power than the rating. I'm sure Big Clive would approve.

author: ogden
author_rank: Super Contributor
timestamp: November 09, 2017, 08:48:20 pm
content: Quote from: orolo on November 09, 2017, 08:23:57 pmAs you did your homework, then I have no other option than to agree. - In case we talk about 100% duty cycle. But as I suggested not only PWM control but also input current (effectively output power) limiter, then RMS figures will be ok. Thou it is not good to 10x exceed current and I shhall agree that 400Hz is too much. Specs shall be revised

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 09, 2017, 09:01:06 pm
content: Quote from: Hero999 on November 09, 2017, 01:50:58 pmyes it does,inverter is at leat 10x more ....hero999 inverter scheme is fined tuned one . but the switcher i will draw later

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 09, 2017, 09:14:27 pm
content: Quote from: ogden on November 09, 2017, 03:30:53 pmworld better place.--yes.... we will save on led lights power usage ,atleast cut bills to 1/3poor gets backup power,solar lamps need smaller battery ..so onbut pwm dimming is of no use as hero999 outlinedthe SCR gives flicker to 5watt LEDS , but 4watts work flawlessly. I will try with triacREading thishttps://www.digikey.in/en/articles/techzone/2012/oct/avoiding-flicker-in-led-lighting-applications

author: Zero999
author_rank: Super Contributor
timestamp: November 09, 2017, 10:06:22 pm
content: Quote from: ogden on November 09, 2017, 07:54:34 pmIt's not that simple as PWMing the power. Read the datasheet, especially the part about toncontrol.Quote from: ogden on November 09, 2017, 08:48:20 pmYes that's pretty much what I was getting at.No one here is being negative for no reason. There are reasons why people here have recommended things such as a higher power inverter or 12VDC LEDs, but the original poster is either, unable or unwilling to implement them.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 10, 2017, 05:56:35 am
content: no worries with lowering of impedance here , smps bulbs only.people will be instructed to buy standard LEDs all are SMPS... we specify make and wattthere are Khz frequency inverters in market , running LEDs for long periods.power-slicing : i call it .....its the TDM ( time division multiplexing) of ACPersonally i try to avoid complexity in implementation. Bringing special chips for the job are last options.I will use just 4017like sequencing ICs so that parts are available everywhere .Quotei already have non-isolated driver based bulbs with similar chips . they too will be used in tests .i may be noob here but Qn ariseswhere PWM dimming has come here ? we dont want to dim the lamps and reduce power .we want same light for a much lesser power

author: mikerj
author_rank: Super Contributor
timestamp: November 10, 2017, 09:43:20 am
content: Quote from: ogden on November 09, 2017, 07:54:34 pmYou seem to be somewhat confused. It's true the very cheap, low power lights use capacitive droppers, but when you are talking about a 10Watt LED lamp for a conventional lamp fitting then it is almost certain to be using a constant current switching regulator. I took apart some cheap GU4 bulbs recently and even those used a switching regulator.If it has a bridge rectifier and smoothing cap, then any attempts to dim the LED through e.g. phase control or PWM will greatly increase the peak current through the rectifier and the ripple current through the smoothing cap.The OP is not saving the world, he's trying to create a very complex solution to what appears to be a simple problem, and refuses to consider any other way of solving it.

author: Zero999
author_rank: Super Contributor
timestamp: November 10, 2017, 10:06:04 am
content: Quote from: mikerj on November 10, 2017, 09:43:20 amI agree. Unless a special type of LED controller is used this won't work.Quote from: dave_j_fan on November 10, 2017, 05:56:35 amIf you want to control the sequence of some lamps, then why not use a microcontroller? It will be more flexible than one of those old ICs and doesn't require as many components.QuoteIf it was possible to produce the same light for less power, then don't you think the LED lamp manufacturers would have already done that?Your scheme will not give you the same light for less power. It will use more power to give you the same light and poorer reliability or slightly less power for much less light, again with poorer reliability.Simply switching the LEDs on and off at a high frequency will not lead to any increases in efficiency, even if such a scheme were compatible with the integrated driver electronics. The human eye perceives the average brightness of a light flashing at a high frequency. If you flash a 10W bulb at 1kHz, equal time on and off, it will appear to give off the same amount of light as a 5W bulb.In practise, if you tried to do that with a ready made LED, with a constant current DC:DC converter, the results will be unpredictable. It might: produce the same brightness but draw double the current, causing potential reliability issues, flicker horribly or just be dimmer.Another factor is the non-linear response of the human eye. A 5W lamp may not appear to be half as bright as a 10W lamp, so even if you think you're successful by using half the power, for a slight drop in apparent brightness, you'll find the 5W lamp would have been a better option.

author: mikerj
author_rank: Super Contributor
timestamp: November 10, 2017, 10:28:44 am
content: Quote from: dave_j_fan on November 10, 2017, 05:56:35 amIf you have found a magical (and it would require magic) scheme to quarter the power consumption of an existing LED lamp for the same light output by manipulating the line voltage then you need to get a patent sorted out ASAP.

author: Zero999
author_rank: Super Contributor
timestamp: November 10, 2017, 11:33:00 am
content: Quote from: dave_j_fan on November 09, 2017, 09:14:27 pmThe prices of solar panels and batteries are falling and are becoming a more attractive option, especially in areas with high electricity prices. There are other options, such as wind and energy from waste (look up biogas and gasification) which can be used to provide power on a small scale.QuoteThat article discusses LED DIMMING, using phase control. It will not help you achieve higher efficiency.

author: Damianos
author_rank: Frequent Contributor
timestamp: November 10, 2017, 12:51:29 pm
content: Quote from: dave_j_fan on November 05, 2017, 10:41:53 amOf course it will do!You can also expand it. At each output from the switcher, connect another switcher ... and, continuing this, you can have unlimited power/energy to lighten up the entire planet.But not only this. If you start combining the outputs after a few billions of switchers, there will be plenty of power for trains, factories, homes, etc.Still, if from some of the outputs re-feed the input, you can save and battery ... After start-up, you can remove it and your invaluable inverter!Watch out! There will be many who will try to steal your designs ... ...To be serious!Are you insisting that a fast switching, with TRIACs or anything else, can cheat on the rules of physics?

author: Connoiseur
author_rank: Regular Contributor
timestamp: November 10, 2017, 01:47:18 pm
content: Quote from: Hero999 on November 10, 2017, 10:06:04 amI would be glad to know the lm/W output of such a contraption.Boy! the OP should watch more free energy videos on YouTube.

author: ogden
author_rank: Super Contributor
timestamp: November 10, 2017, 09:10:04 pm
content: Quote from: mikerj on November 10, 2017, 09:43:20 amBefore you label someone as confused, you shall comprehend what he is talking about. I shall remind that main topic was not "capacitive droppers" as such but exceeding ripple rating of input capacitor and it's consequent failure. Even in case of constant current switching regulators square wave input shall not accelerate failure rate unless design is flawed. Knowing target customer and assuming that he will buy 10W LED bulb with current switching regulator inside is kinda... uneducated thinking. If total power provided for 4 bulbs is 10 watts - then what's the point of paying for 4x10W bulbs?Quote from: mikerj on November 10, 2017, 09:43:20 amIf LED is designed as dimmable, it will work. Try to think of solution too, not only just dig up flaws. Actually latter is much easier.Quote from: mikerj on November 10, 2017, 09:43:20 amOh, Mr.Obvious. Do you know concept ofsarcasm?

author: Zero999
author_rank: Super Contributor
timestamp: November 10, 2017, 09:50:12 pm
content: Quote from: ogden on November 10, 2017, 09:10:04 pmThe power dissipation in the capacitor/inrush limiting resistor will be higher with a 50% duty cycle square wave, than a sine wave. If the inrush limiter has a negative temperature coeffient, then it might be fine, since the increased current might reduce the resistance enough to avoid the power dissipation getting too high, otherwise it could fry.See the attached simulation. With a 500Hz 50% duty, 325V (the peak voltage for 230VAC), the power dissipation in R1 (the surge limiting resistor) will be 500mW. When V1 is changed to a 500Hz square wave, the power in R! increases to over 2.5W. I'll attach some screenshots later.QuoteIt might work or it might not. It depends on how the dimming is implemented. With the IC data sheet I linked to earlier, it certainly wouldn't work.QuoteUnfortunately sarcasm often gets lost in the depths of the Internet.

author: ogden
author_rank: Super Contributor
timestamp: November 10, 2017, 10:55:51 pm
content: Quote from: Hero999 on November 10, 2017, 09:50:12 pmDid not able to interpret .asc file provided, sorrry.Your beginners error is that square wave inverter will not output "325V (the peak voltage for 230VAC)" but 230VAC RMS voltage which is essentially 230V peak.So, RMS power dissipation in R! in case of square wave will be identical. Where's the catch? Actually I was beginner here, apologies. 230V peak of square wave inverter at 100% duty cycle will give same power as RMS 230VAC only for resistive loads. LED with rectifier inside needs 325V peak disregarding it is sine or square wave.Quote from: Hero999 on November 10, 2017, 09:50:12 pmDetailed explanation please .

author: Zero999
author_rank: Super Contributor
timestamp: November 11, 2017, 12:06:14 am
content: Quote from: ogden on November 10, 2017, 10:55:51 pmNo.For a start, in order to work properly, the inverter would have to output a voltage of 325V, since that what will be on the capacitor, after the rectification of the 230VRMS mains, which has a peak voltage of 325V. Don't believe me? Connect a 12VAC transformer to a bridge rectifier and capacitor. You'll find that the voltage on the DC side, is equal to about 1.414 times the AC side, minus the diode losses. Even if the voltage were reduced to 230V, the power dissipation would still be higher, than for a sine wave.QuoteDid you refer to the data sheet, paying attention to the part about toncontrol, pin 8, the TONMOD pin? The dimming function is dependant on the timing of the sine wave on the input to the rectifier.http://www.mouser.com/ds/2/302/SSL21082AT-843512.pdf

author: kalel
author_rank: Frequent Contributor
timestamp: November 11, 2017, 12:07:18 am
content: As (little) as I know, multiplexing does decrease the brightness we perceive, since each LED is only on for some time. Even a single LED switching "on off" faster than we can see will produce less light than a constantly on LED, because it will be some "on and off" output average that we see rather than just "on" output.As far as capacitive droppers, I'malmostcertain I have seen capacitive droppers in cheap claimed 9/10W LEDs. I haven't measured the wattage to see what it outputs really, but they are quite bright, and don't last too long (up to a few years). Sometimes the LEDs get burned (lack of proper heat-sinking?) - they first get darker spots, still work for a while - and finally fail, sometimes the electrolytic capacitor fails (it does get moderately heated, I don't know how a better capacitive dropper design could mitigate this issue).

author: ogden
author_rank: Super Contributor
timestamp: November 11, 2017, 02:40:40 am
content: Why you are using 50Hz for sine and 500Hz for inverter? Anyway - you just completely ignore all the other "specs" of the project including 10W power limiting of inverter output, it's duty cycle which for sure will not be 100%, you put hi-voltage 47uF capacitor into low cost LED (!).Also this:>Did you refer to the data sheet, paying attention to the part about ton control, pin 8, the TONMOD pin?is not detailed explanation but more like trolling.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 11, 2017, 10:12:00 am
content: QuoteThe point of getting reduced light like 5Wled bulb from 10w with 1khz frequency is not valid , in khz range the LED gives almost same brightness.I have tested it, with few brands like hevells, philips ..For the point "flicker" "dimmer" is also not fully true .my Jig already achieved same light for 4W LED . I have tested with SCR as active element .yes the 5W led gived a breathing like fliker mey be because SCR have reduced the voltage .I have reduced the off period to 1sec and the SCR switch is giving flicker , means..TRIAC tests will ... hopelfully make the jig workThe discussion is very informative. I am going baby steps way to make the jig flicker free .Jig will feed from a small diy inverter .... DC current i will measure and find the truth .remember JOULE ringers running 10LED bulbs ...so possibility is always there

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 11, 2017, 10:17:41 am
content: will see ...for your information i have a DC led tube , i added PWM and reached 12hours light ... originally it was giving 3-4hourdont bring physics if you dont know pulsed and switched led lighting saves lot energy .however i have less test knowledge on AC so asked experts

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 11, 2017, 10:21:25 am
content: Quote from: dave_j_fan on November 11, 2017, 10:20:02 amwill see ...for your information i have a DC led tube , i added PWM and reached 12hours light ... originally it was giving 3-4hourdont bring physics if you dont know pulsed and switched led lighting saves lot energy .however i have less test knowledge on AC so asked experts

author: ogden
author_rank: Super Contributor
timestamp: November 11, 2017, 12:01:49 pm
content: Quote from: dave_j_fan on November 11, 2017, 10:21:25 amYou assume you are getting same light output while LED is PWM-dimmed, but you are not. Do you have lux meter to measure light output? If not, then take two identical LED bulbs, run one w/o PWM and another with PWM at the same time so you can compare brightness. It will differ for sure.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 11, 2017, 01:28:38 pm
content: Quote from: ogden on November 11, 2017, 12:01:49 pmit may be slight reduced but probably reducing heat loss it maintains good amount of intensity.The tube is very good usable light for small kitchen.I have even distributed Khz range power boosted lights . 12v to 230v . pulsed mode maintains nearly same intensity in bulbs .My observation.I junked 3 circuits for lower light , finally found super bright one

author: Zero999
author_rank: Super Contributor
timestamp: November 11, 2017, 04:17:33 pm
content: Quote from: ogden on November 11, 2017, 02:40:40 amBecause an off the shelf LED lamp will be designed for 50Hz operation, not 500Hz. Think about it.QuoteIt's typical for the input stage of a mains powered LED. Do some research, before making stupid comments.QuoteDon't accuse others of trolling, just because you don't understand something.Quote from: dave_j_fan on November 11, 2017, 01:28:38 pmHave you measured the power consumption?Have you done any objective measurements of the brightness, using a meter, rather than ones eyes?Bear in mind the eyes can easily be fooled. A 10W bulb won't look twice as bright as a 5W bulb.

author: ogden
author_rank: Super Contributor
timestamp: November 11, 2017, 06:35:32 pm
content: >Because an off the shelf LED lamp will be designed for 50Hz operation, not 500Hz. Think about it.Oh, thank you for schooling. Actually I wanted to know where 500Hz for inverter came from>It's typical for the input stage of a mains powered LED. Do some research, before making stupid comments.47uF typical for low cost LED bulbs? - Show your data.>>>Did you refer to the data sheet, paying attention to the part about ton control, pin 8, the TONMOD pin?>>is not detailed explanation but more like trolling.>Don't accuse others of trolling, just because you don't understand something.Thenexplainin details so we can understand why particular chip will work from dimmed 50Hz sine wave but will not work from 50Hz PWM square wave. I want to know which part of mentioned datasheet explains that. So I ask you again: please givedetailed explanation.

author: Zero999
author_rank: Super Contributor
timestamp: November 11, 2017, 07:51:59 pm
content: Quote from: ogden on November 11, 2017, 06:35:32 pmPlease read the thread from the beginning. The original poster intends to drive a bulb rated for 50Hz, using an inverter with a much higher frequency square wave. It should work with a continuous duty cycle +/-230V to 325V square wave, as long as the frequency isn't too high for the diodes in the bridge rectifier to switch, but not for a square wave with 50% duty or modified sine wave.The value of the filter capacitor is not important. It was an example of a typical input stage of an LED lamp. Bridge rectifier -> surge limiting resistor -> capacitor. The idea was to demonstrate, that powering it from a 50% duty cycle square wave can cause excessive power dissipation in one of the components. Another issue is, this may work on the bench but prove unreliable in the field. Often overstressed components don't fail immediately but blow up much later.The dimming function of that is dependant on the mains frequency being near 50Hz, 60Hz or whatever the circuit is designed for and changing the frequency will mess it up. Don't forget that he doesn't have any control of the circuit being used to power the LED, only the voltage input to it. Another issue is he doesn't want to dim the LED. He wants to power it at full brightness, whilst reducing the power consumption: an impossible feat!

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 11, 2017, 07:53:26 pm
content: Quote from: Hero999 on November 11, 2017, 04:17:33 pmi respect that new information ... i stated by observation of the light in the room not just bulb on table.Today 2 channel test success with 5Watt and 4watt .the 5watt leds had flicker,todays test used TRIAC. It is maintaining good brightness.may be 3-4channel mux will be ok.all inverters i have given to poori will get parts and test 1bulb inverter to drive 2 bulbs.technically it must work because 230V test is promishing .Just frequency is in khz range .

author: ogden
author_rank: Super Contributor
timestamp: November 11, 2017, 11:48:50 pm
content: >Please read the thread from the beginning. The original poster intends to drive a bulb rated for 50Hz, using an inverter with a much higher frequency square wave.I can say the same to you because:1) I am not original poster2) I suggested inverter with tunable frequency 50-400Hz range and tunable duty cycle, with input current limiter which will essentially limit output power to nominal.3) you jumped on me when I said:"I shall remind that main topic was not "capacitive droppers" as such but exceeding ripple rating of input capacitor and it's consequent failure. Even in case of constant current switching regulators square wave input shall not accelerate failure rate unless design is flawed."4) Then you came up with LTspice design where you conveniently (for you) ignore fact that inverter frequency, output voltage and duty cycle can be adjusted to meet design requirements one of which would be "do not accelerate LED bulb failure".I suggest you to run your inverter LTspice not with 50% duty cycle, but 100% which essentially is DC coming out of bridge rectifier, tune peak voltage so LEDs dissipate identical power compared to AC sinewave design and only then check power dissipation in the inrush limiter resistor. Maybe then you will understand what I did mean by saying "Even in case of constant current switching regulators square wave input shall not accelerate failure rate unless design is flawed.".>The dimming function of that is dependant on the mains frequency being near 50Hz, 60Hz or whatever the circuit is designed for and changing the frequency will mess it up.well then dont change it. remember? - I did leave 50Hz option in my offer.

author: Zero999
author_rank: Super Contributor
timestamp: November 12, 2017, 12:17:25 am
content: Quote from: ogden on November 11, 2017, 11:48:50 pmNo but you can read what they've written.QuoteThe original poster mentioned using a higher frequency, than 50Hz mains first.https://www.eevblog.com/forum/beginners/10watts-for-all-4-will-it-work/msg1344171/#msg1344171QuoteNo one jumped on anyone. The point was that there are a variety of different designs of LED lamps. It's impossible to know what they'll do when you change the input frequency/duty cycle, without lots of prior testing or reverse engineering. What's worse is that with a standard fitting, someone could easilly change the lamp to an incompatible one, which could blow up.QuoteNo, I modelled the typical input stage of an LED lamp and explained why it can overheat if you try to dim it by PWMing the input voltage.QuoteI know and even said previously that it will work off DC, but what's the point when with 100% duty cycle, there will be no reduction in power consumption or brightness?https://www.eevblog.com/forum/beginners/10watts-for-all-4-will-it-work/msg1345097/#msg1345097Varying the supply voltage (whether AC or DC) will not change the brightness or power consumption of some LED lamps, because they contain a constant current driver, which tries to keep the current through the LED chips the same, despite changes in supply voltage.QuoteGood and better made it a pure sine wave, which is a more complicated inverter design, just to be sure it works.Quote from: dave_j_fan on November 11, 2017, 07:53:26 pmPlease post some schematics of what you've already done.Have you tried it with a variety of different LED lamps? Is there a risk the user might do something silly like replace the LED lamp with an incandescent or compact fluorescent?

author: ogden
author_rank: Super Contributor
timestamp: November 12, 2017, 01:02:38 am
content: Quote from: Hero999 on November 12, 2017, 12:17:25 amI did. On the other hand, you did not read what I wrote.QuoteHow many times I shall remind you that you opposed me, not original poster?QuoteIf everything is designed correctly - nothing will blow up.QuoteWell... as I indicated - you did it wrong.QuoteDC is starting, "calibration point" - for you to correct your LTspice LED bulb simulation. After you tune design to work correctly off DC, you will see that it will not tend to blow up when PWM'ed to lower than 100% duty. Proper dimmable square wave inverter will not blow up LED bulbs faster than triac dimmers. This is what I am telling you all the timeQuoteYou are kidding me or what? Please re-read it carefully: "tune peak voltage so LEDs dissipate identical power compared to AC sinewave design and only then check power dissipation in the inrush limiter resistor".QuoteActually I believe that original poster have better option: instead of designing, manufacturing and selling inverter & fancy 4-led sequenced to end-customers, better just sell them 12V LED bulbs

author: Damianos
author_rank: Frequent Contributor
timestamp: November 12, 2017, 01:36:38 am
content: Quote from: dave_j_fan on November 11, 2017, 10:21:25 am[... even if you have mixed up the quotes and you are answering to yourself!]Oh! I know a lot of things, but I keep some secrets!The nature was born before the LEDs and switchers, so does not know about them!Also, I know that half of the power on LED lights hidden somewhere and waiting for an enlightened to reveal it!I work on a similar project but much more advanced. As you know LEDs are also light detectors, they generate voltage and current when light hits them. Using a suitable mirror and switching them fast, they produce energy from their own light! The only unsolved problem is synchronization of switching with the time that the light beam needs to travel up to the mirror and return back. As I don't know enough aboutpulseand switching circuits, I use apushingswitch manually. I need some help to slow the switch contacts, as they are faster than light ... ...

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 12, 2017, 03:11:55 am
content: apart from law of physics and ranting why it wont work.Why not some members try it..$5 in parts wont hurti am not saying physics is bypassed but telling non conventional ways to light leds.The work by lidmotor in energetic forumsshow that with less watt also you can get same brightness.Experiment ,change,try.mcu> 4017>triaccircuit is as simple as that- -----for people fighting on "what will work" why not come with own test jig post real reading of ac powerwhile running battery drain tests in my inverters i checked some random things and found adding 100uH inductor in series on ac side , or 1uf 400v cap in seriesthe battery drain is reduced.Be practical you will discover some secrets--is the objective is to save power ?Not exactly but if we can good . First target is to reduce loading of the inverter.25W inverter if it can run 50w leds ....we save lot on per inverter cost .common people benifitted with econmical invertersgetfull house lights for too lowspending .They need small battery that further reduces cost .

author: ogden
author_rank: Super Contributor
timestamp: November 12, 2017, 09:11:09 am
content: Quote from: dave_j_fan on November 12, 2017, 03:11:55 amDid you wear tinfoil hat while discovered those secrets? BTW you can reduce battery drain even further by switching your inverters off. Such experiments that just measure consumed power without measuring resulting light output are useless.

author: Zero999
author_rank: Super Contributor
timestamp: November 12, 2017, 01:59:43 pm
content: Quote from: ogden on November 12, 2017, 01:02:38 amYes, it did. It was wrong and someone else, as well as myself, corrected it.QuoteWe did inform the original poster that this could be an issue and don't take things so personally: if you post something which is incorrect, people will correct you.QuoteAnd operating an unknown LED lamp from a PWM square wave is bad design, so there's a risk it will blow up. Even if you manage to optimise the design for a particular brand/design of LED lamp, it's in a standard fitting, so there's a risk someone might change the bulb for an incompatible one, which will blow up.QuoteHow is it wrong? If I made any errors, please point them out and correct them. Bear in mind there are lots of different LED lamp designs. . .Here's another mains powered LED lamp design. This time I've posted the full schematic. It's worse because it has no inrush limiter. C1 and D1 to D4 may be able to handle the occasional inrush, but PWM this and it will be destroyed.https://www.alibaba.com/product-detail/Proxy-AC-LED-Driver-IC-FT838RNA_1624190417.htmlQuoteNo, there is a risk it will blow up. Suppose the circuit can safely run off 230VDC safely, without any problems, it does not mean that it can run off 230V with 50% PWM safely. Every time the power is applied, a large current flows through the surge suppression resistor to charge the capacitor. The bulb will only be designed to be turned on occasionally, not turned on and off, from an abrupt square wave hundreds of times per second.PWM is only good for controlling the power delivered to linear loads such as resistors and motors. It is no good for non-linear loads, such as switched mode power supplies, which are often found in modern LED lamps. Just because you can PWM an LED + series resistor, it doesn't mean you can PWM a mains LED lamp.QuoteAnd how are you going to check the power dissipation in the inrush limiter, inside the LED bulb, without dismantling it? Bear in mind that it's difficult/impossible to open some LED bulbs, without damaging them in the process and as mentioned above, the bulb is in a standard fitting, so the user might replace it with another one which won't work the same way.QuoteI agree. He's been told that plenty of times.Quote from: dave_j_fan on November 12, 2017, 03:11:55 amYou'll get a more positive response if you actually posted schematics showing what you're doing.If you really are intent on saving the planet, rather than making money, then you shouldn't keep anything secret. Spread the information, so others can join your quest to save the planet.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 12, 2017, 05:22:48 pm
content: Quoteno one should come here after few shots ofhttps://i.pinimg.com/736x/8d/e1/cf/8de1cf0f2067f77759f1023c75d48e38--whisky-jack-jack-daniels-single-barrel.jpgHero999,Here I am donating the billion dollars ..!Code:/** Simple LED sequencer using a 4017 counter.* The 4017 is used to save pins on the arduino.** Developed by daveJ Fan**//* PIN used to send clock pulses to the counter. */int clockPin = 2;void setup() {pinMode(clockPin,OUTPUT);}/** Sends a clock pulse to the counter making it advance.*/void clock() {digitalWrite(clockPin,HIGH);delay(1);digitalWrite(clockPin,LOW);}void loop() {/* Send a clock pulse to the counter. It makes the counter advancecausing the current LED to be turned off, and the next one to beturned ON */clock();/* Wait for 30 ms. */delay(30);}well code is copied and at the output LEDS there is a opto-TRIACIts too easy .Even simple 555 will work with this ..Quoteyou have motivated meto do the right thing

author: Zero999
author_rank: Super Contributor
timestamp: November 12, 2017, 05:28:47 pm
content: I take it the IC on the right hand side is the CD4017?Why not just use the Arduinio? There's no need for the CD4017.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 12, 2017, 05:38:00 pm
content: arduino will be retiredto cut cost , adding bjt /555 lateryes , IC on right is 4017

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 12, 2017, 05:47:32 pm
content: for people with interest thejohnny aum night light. is an example of getting very nice light with 51Milliwatts power, driven LED is 2.8watts ! Point is there are many possibilitieshttp://www.energeticforum.com/296163-post38.html?s=03f790b602cb7fbdb175e0416c3a83d4

author: ogden
author_rank: Super Contributor
timestamp: November 12, 2017, 06:02:30 pm
content: Quote from: Hero999 on November 12, 2017, 01:59:43 pmKeywords here are dimmable LED bulb and LED bulb that tolerates triac dimmers. Please read below.QuoteError 1) You compared dissipation of each inrush limiter resistor without showing dissipation in each "LED equivalent" made out of current sink. For fair comparison they must be equal. So basically useless comparison.Error 2) You compared 100% duty cycle (undimmed) AC mains to 50% duty cycle square wave. Again useless comparison.QuoteRight. Those which will fail from leading-edge mode triac dimmer input most likely will fail from square wave too. - As I said already multiple times that "Proper dimmable square wave inverter will not blow up LED bulbs faster than triac dimmers."QuoteWell, thank you. For balance I will share one much more interesting - from engineering point of view.https://www.fairchildsemi.com/product-technology/direct-ac-drive/QuoteWhen dimmed from leading edge mode triac, sharp pulse up-to full Peak-Peak voltage of AC mainseach half-cyclewill be applied to it while at particular dimmer setting:Further reading:http://www.ledsmagazine.com/articles/print/volume-8/issue-6/features/led-lighting-must-work-with-legacy-dimming-technologies-magazine.htmlQuoteThat one particular LED bulb controller you gave datasheet for, does support triac dimmers, both leading and traling edge. Hows that?QuoteCrlt+click on waveformYes, I did talk about your LTspice simulation, not LED physical bulb.

author: Zero999
author_rank: Super Contributor
timestamp: November 12, 2017, 07:01:11 pm
content: Quote from: ogden on November 12, 2017, 06:02:30 pmThat's all fine, until the user replaces it with a non-dimmable lamp.QuoteWhat do you mean by LED equivalent? The power rating of one of the components is exceeding its rating by a factor of 5, when run on a 50% duty square wave vs the sine wave it was designed for!QuoteI agree so perhaps my simulation, wasn't so incorrect after all. It demonstrates why a non-dimmable LED will fail, when operated from PWM.QuoteIt supports TRIAC dimmers, not PWM! They are not the same thing!Ok it might not blow up but flicker, when run off the wrong frequency square wave, rather than a sine wave. Still not good.Why not simply use a 50 or 60Hz sine wave inverter and a proper dimmer circuit for a dimmable LED lamp, rather than risking failure with a square wave, at the wrong frequency? That's a much better solution. Use components, as they're designed to be used, within their specifications. Attempting otherwise, only leads to trouble, further down the road.By the way, thank you for posting the second link. It might help to explain to the original poster, why his LEDs aren't getting any dimmer.QuoteWhat do you mean by?QuoteI re-read it several times and it makes no sense!The LTSpice simulation was an approximation of an LED driver circuit, run off a bridge rectifier and capacitor. The LED is modelled as a current source, but in reality, it will be a constant power circuit, i.e. a switched mode power supply. The input current will increase, as the voltage on the capacitor falls (down to a certain point of course) which should theoretically, increase the power dissipation on the surge limiting resistor, as the supply voltage is reduced. The end result will be the same: PWMing it will cause no dimming and premature failure.Quote from: dave_j_fan on November 12, 2017, 05:38:00 pmAnother option is a ring oscillator. I designed a PCB for one awhile ago, as a learning exercise.https://www.eevblog.com/forum/beginners/my-latest-eagle-pcb/msg10497/#msg10497By the way, no that would not make mains LEDs use less energy, but keep the brightness the same. They will either get dimmer, or the controller IC inside the mains LED lamp, will increase the current draw, to keep the brightness constant. If the latter happens, there's more risk of premature failure of the LEDs or inverter, used to drive them. You need to invest in a power meter. One which will work with a square wave and at different frequencies than the standard 50 or 60Hz mains. Measuring the voltage and current simultaneously and applying Ohm's law doesn't give you the true power, although it will give you a good idea of whether the inverter's output current rating is not being exceeded.I have a non-dimmable mains LED lamp. I've tried using it with a phase controlled dimmer. The brightness stays constant, until the dimmer setting is reduced past a certain point, then it starts flickering and stops working. I have not measured the power consumption with the dimmer, but I'm pretty sure that it's not using less power, with the dimmer, than without it. I didn't test it for long, because it's likely it would have damaged the dimmer.Quote from: dave_j_fan on November 12, 2017, 05:47:32 pmThat looks like a Joule thief. A very old circuit. It's totally different to what you're doing, because the LED's driver has been removed, so it's powering a bare LED. That circuit doesn't magic 2.759W from nowhere! The 2.8W bulb is clearly running at a fraction of its rating brightness, because the current through it is much lower than the rating. It's true that driving an LED, at a lower current, than its maximum rating increases the efficiency, up to a certain point, but it works out very expensive to buy LEDs rated for much more power, than they'll be driven with, so LED manufacturers won't do it. How many people would by a 1W LED which costs nearly as much as a 10W LED?

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 12, 2017, 07:40:08 pm
content: Quotesuperb option , how to make it a variable freq one , adding 10K Vr in feedback ?QuoteI know abt JT and made 5 types some time back , but the circuit is not a exact JT as there is no twocoils with 3 pint connection than itz a series connected coil type .What is interesting is 51milliwatts !! for 75% 'usable light' ,this gives me idea of pushing the 9W for all room light with this type circuit. This type of boosters will run well in shops and 1student room alikes .

author: Zero999
author_rank: Super Contributor
timestamp: November 12, 2017, 08:14:56 pm
content: Quote from: dave_j_fan on November 12, 2017, 07:40:08 pmThe values of all of the 10k resistors need to be varied, which is probably not practical.QuoteThere are several different variants of the classic Joule thief circuit. In this case, because both of the coils are connected in series and are magnetically coupled, they behave like one coil.QuoteDon't let the picture fool you. It isn't using 51mW to produce 75% of the light of a 2.8W lamp. It's an illusion.

author: ogden
author_rank: Super Contributor
timestamp: November 12, 2017, 09:39:16 pm
content: Quote from: Hero999 on November 12, 2017, 07:01:11 pmChecked your LTspice design and agree - "dimmer incompatible" LED bulb which is based on constant current IC, most likely will fail due to overheat.QuoteThey are indeed. PWM synced to AC mains phase and frequency can do same thing as triac dimmers do. PWM does not relate only to DC chopping. You can do PWM on any waveform you want.If you feed dimmer-compatible LED bulb IC with 50Hz(!) square wave - it will sync to it. When you PWM-chop 50Hz bipolar square wave coming out of push-pull or full-bridge inverter, then dimmer-capable LED bulb IC will happily detect dimming. Am I missing something here?

author: Zero999
author_rank: Super Contributor
timestamp: November 12, 2017, 10:13:39 pm
content: Quote from: ogden on November 12, 2017, 09:39:16 pmPWM has a similar effect to phase control but it is not the same thing. PWM isn't normally used in AC circuits, because it's much easier to use phase control and when it is used, it's usually referred to as burst or full-wave duty-cycle control. The PWM is synchronised to a much lower frequency than the mains, causing it to get chopped up into blocks of full cycles, followed by off periods. The ratio of full mains cycles, to off periods is the duty cycle.It looks like this:Obviously this is no good for lighting, because it will flicker, unless the AC frequency is very high, so it's used for heating. The main advantage over phase control is, switching only ever occurs at the zero crossing time, there is no abrupt switch on/off of current, so it's less noisy.If the sine wave is PWMed at a much higher than its fundamental frequency then it will be chopped up into tiny pieces and look like the right of the image below. On the left shows phase control, which many people confuse with PWM.http://www.edgefxkits.com/ac-pwm-control-for-induction-motorI imagine it's very noisy, which is why I've not seen it in real life, only on forums.As far as powering a dimmable LED lamp, which is designed for use on 230V 50Hz AC, from PWM DC is concerned: it may, or may not work. To stand the highest chance of success, use 100Hz or 120Hz, rather than 50Hz, because that's what the LED driver IC will see on the DC side of the rectifier.

author: ogden
author_rank: Super Contributor
timestamp: November 12, 2017, 10:32:34 pm
content: Quote from: Hero999 on November 12, 2017, 10:13:39 pmIndeed dimming is rightwordfor AC mains phase control but principles to PWM is the same - as I already explained. So to say "Dimming is not PWM. Period." is not quite correct as well.QuoteIt is. Modern PFC uses hi-freq PWM for AC mains power factor correction. Waveform looks like you are showing "the real PWM control of AC".QuoteYou (again) ignored what I say. Reminder in bold:50Hz bipolar square wave coming out of push-pull or full-bridge inverterafter rectification will look like pulsing 100Hz.

author: ogden
author_rank: Super Contributor
timestamp: November 12, 2017, 11:26:25 pm
content: Anyway soon all LED bulbs will have no switching converters or bulk capacitors which are main contributors to price and failures too.From inside they will look like this:Not like this:Such design with PF approaching 0.98 acts like resistive load and will have no problems to work from any waveform you drop at it. Just don't exceed voltage rating

author: kalel
author_rank: Frequent Contributor
timestamp: November 13, 2017, 01:34:31 am
content: If I have seen it right, it looks like a circuit with an integrated driver (I don't know what else to call it), similar to the video below. Don't those designs experience a lot of flicker as is?There might be new designs that solve the flickering, or perhaps what you showing in the image is a different type of circuit all together.

author: ogden
author_rank: Super Contributor
timestamp: November 13, 2017, 07:53:34 am
content: Quote from: kalel on November 13, 2017, 01:34:31 amDifferent indeed.QuoteExactly opposite.They are based on AC-direct regulation IC which progressively switches on each of 4 LED strings until all are illuminated at the mains voltage’s peak. Note that for simplicity circuit below shows just 3 strings. This allows to "cover" with illumination nearly all the AC mains cycle. Resulting light is nearly flickerless.Article here:https://www.electronicsweekly.com/news/why-not-direct-ac-drive-your-led-string-2016-04/I already mentioned ON Semi FL77904 which is single chip 4-string IC requiring few small passives, bridge rectifier and that's it. Power factor better than 0.98(!). It is beauty if we can say so about engineering.http://www.onsemi.com/PowerSolutions/product.do?id=FL77904

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2017, 08:50:45 am
content: Quote from: ogden on November 12, 2017, 10:32:34 pmDimming is not the right word for AC mains phase control, since it can be used for other purposes than lighting, such as controlling the speed of motors and the power output of heaters.QuoteNot quite. Power factor controllers, PWM the DC side of the rectifier, not the AC side.QuoteOh I see what you meant now. No I wouldn't recommend doing that. Chopping the output of the inverter, would result in much higher frequency components, which might not play nicely with the LED driver, unless you're talking about something else.It would be better to rectify the output of the inverter, then PWM that at 100Hz.

author: ogden
author_rank: Super Contributor
timestamp: November 13, 2017, 11:27:46 am
content: Quote from: Hero999 on November 13, 2017, 08:50:45 amAgain you assume inferior design.All UPSes with "simulated sine" output have what we call here "chopped inverter". Yet they somehow pass EMC regulations, computers are happy with such waveform, most likely LED bulbs will too. Chopping happens on primary side of the transformer, output have just quite simple (L)C filter.Having proper snubbers on primary and some filtering on secondary winding of the transformer, output looks not that bad at all (from hi-freq ringing point of view):https://www.hardwareinsights.com/database-of-ups-output-waveforms/QuoteSuch waveform will cause much worse inrush current problems than modified sine wave, drooper-capacitor LED bulbs most likely will be very unhappy about such input too. When you feed such modified sine into your "LTspice LED bulb", you will see that 10ohm resistor dissipates only ~1W at full power and ~1.1W when 50% dimmed. This BTW is just 2x exceeding "pure sine rating"

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2017, 12:28:45 pm
content: Quote from: ogden on November 13, 2017, 11:27:46 amNow you're making an assumption too: that output of the original poster's inverter is a modified sine wave. You've also forgotten that the original poster doesn't want to or cannot change the inverter.Unfortunately we have to make assumptions, in the absence of all the information. The original poster has not posted a schematic or an oscillogram of the output waveform of their inverter, so we don't know the full story.QuoteDC PWM will be no worse or no better than a modified sine wave, for the circuit I simulated in LTSpice. Yes a capacitive dropper won't work from PWM DC because, it will be blocked by the capacitor.QuoteYes, still not good though and could lead to reduced reliability.

author: ogden
author_rank: Super Contributor
timestamp: November 13, 2017, 12:39:27 pm
content: Quote from: Hero999 on November 13, 2017, 12:28:45 pmYou'v forgotten that you discussing to me here, not original author. I do not share authors plans, provided mine in return. Obviously when I say something about inverters and so on, I am considering my view, not original posters plans. That's it. Tired of reminding. Bye.

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2017, 12:49:26 pm
content: Quote from: ogden on November 13, 2017, 12:39:27 pmAnd you've forgotten that this is not your thread! By barging in to some one else's thread, you've derailed it and created pages of useless information, which is totally irrelevant to the original poster's question, which is not helpful.If you wanted to discuss your inverter/LED lamp design, then you should have created your own thread, rather than derailing someone else's!I apologise to the original poster for playing my part in this. I should have recognised this and stopped responding to you, long ago.

author: mikerj
author_rank: Super Contributor
timestamp: November 13, 2017, 01:18:05 pm
content: Quote from: ogden on November 12, 2017, 10:32:34 pmNot a single person has stated such nonsense as "Dimming is not PWM. Period." If you have to resort to making things up then your argument is a lost cause.As for you PWM AC waveform doubling the power dissipation in the 10R resistor, why do you think this is acceptable? Do you believe that mass produced LED lamps are all sufficiently over-engineered that you can ignore this?

author: ogden
author_rank: Super Contributor
timestamp: November 14, 2017, 01:06:42 am
content: Quote from: Hero999 on November 13, 2017, 12:49:26 pmSo you say that someone who offers alternate solution for consideration, actually creates "pages of useless information, which is totally irrelevant to the original poster's question". With emphasis on "totally irrelevant".QuoteAre you serious? How many times didyouoffer something that differ from original poster's plans? - Shall we count? Or maybe you did not offer anything useful, just denied everything you did not agree to?

author: ogden
author_rank: Super Contributor
timestamp: November 14, 2017, 01:29:16 am
content: Quote from: mikerj on November 13, 2017, 01:18:05 pmWell, Hero999 stated: "It supports TRIAC dimmers, not PWM! They are not the same thing!". In my opinion saying "Dimming and PWM are not the same thing!" (pay attention to exclamationsignmark) is the same as "Dimming is not PWM".QuoteI did agree that this is not acceptable. Perhaps you missed that (as usually happens here in thisforumthread):Quote from: ogden on November 12, 2017, 09:39:16 pm

author: ogden
author_rank: Super Contributor
timestamp: November 14, 2017, 01:45:38 am
content: Quote from: ogden on November 14, 2017, 01:06:42 amActually I did good service to thread - created special attention to square wave inverters which are not compatible with some LED bulbs. I doubt that 5$ inverter mentioned by original poster, is pure sine wave one. Disregarding this fact you did offer your ring oscillator. No further comments...

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 14, 2017, 05:20:21 am
content: Quoteits ok Hero999, not your faultI request the other poster to keep discussion to target the plan of mux on the AC line .Let us not go deep into LED drivers and million inverter design. Then it will be like making a chair for 2yo to 90yo with a size that fits all .We are engineers , seek to make viable products not science explorer .-some good news here!!! -The plan works by unloading the invertera small inverter that used to flicker after 15watts now happily taking 25W , pretty amazing bright lights .i am too lazy to make lux meter but compared lightof 1 bulb with MUX and without MUX .Did it save power ?Not much,9watter was pulling 800mA DC25watts load was showing 600mA / per 5watts draindid the lamps over heat ?NOi wish someone could fund me for a patent!Many experts cant achieve to a solution because they lose focus , so it is better the discussion can limited to reach some solutionthese are the parameters for a BETA of the AC MUX=============- Approx square wave ( a little different in my case ) inverter , take frequency 10khz-target is to get atleast 4 bulbs on 10w inverter-all bulbs are SMPS ( no future tech and , cap dropper)===================================There are 2 ways-simulation model-real oneSecond one will save time initially

author: Zero999
author_rank: Super Contributor
timestamp: November 14, 2017, 08:53:54 am
content: Quote from: ogden on November 14, 2017, 01:06:42 amYou didn't contribute any schematics, simulations or ideas to the thread. I posted a simulation which demonstrated what happens to the input stage of a mains LED, when driven with various waveforms. All you did was derail the thread with nonsense about it being fine to overstress parts, dimmable lamps and PWM and phase control being the same thing.Quote from: dave_j_fan on November 14, 2017, 05:20:21 amYou can't rely on your eyes to make quantitative measurements. A lux meter is the only way to perform objective tests.I suggest doing long term trials. Just because they're SMPS, it doesn't mean their reliability won't be affected.Have you looked at the output current and voltage waveform of your inverter with an oscilloscope?

author: ogden
author_rank: Super Contributor
timestamp: November 14, 2017, 11:49:33 am
content: Quote from: Hero999 on November 14, 2017, 08:53:54 amI did. Very early in this thread I said: "I would run all the LED bulbs in parallel - to save on wiring in many installations and create10W PWM-dimmable AC square wave inverter with input current limiter. Current limiter as safeguard against inverter overload and output short. "QuoteYou posted simulation which uses inverter of infinite power just to prove your uneducated point, ignoring fact that original poster mentioned 10W (in the topic of this thread). If we take in account limited power of the inverter which can sustain let's say 1A max output current, then "parts overstress" picture changes dramatically and inrush resistor dissipates just 155mWaverage during 1sec of simulationwhich is few times less than nominal which you put at 500mW. Simulation attached.QuoteIt is actually you who are spilling nonsense all over this thread by literally attacking me with sentences like this, providing misleading "facts" using simulations that proves nothing more than how incompetent or careless you are. I do not recall saying "it is fine to overstress". I said - if everything is designed properly then nothing will blow up meaning there will be no parts overstress.

author: ogden
author_rank: Super Contributor
timestamp: November 14, 2017, 07:52:04 pm
content: For those who still believes that square wave is much worse for LED bulb than sine, I offer to consider that bulbs shall be designed to withstand power-on at any phase angle of AC mains including max peak voltage, otherwise they will blow-up nearly every power-on. Best and worst case dissipation of inrush resistor results for AC mains sine attached. Best case obviously - to show that it gives result we already know, 0.5W @ 1sec.Worst case is much more interesting.. because it's 2.49W is pretty close to "LED blown-up by square wave" simulation result of 2.54W

author: ogden
author_rank: Super Contributor
timestamp: November 14, 2017, 08:13:47 pm
content: Quote from: dave_j_fan on November 14, 2017, 05:20:21 amSorry, I had to correct misleading information Hero999 provided here - regarding LED bulbs on square wave supply.AC line? Do you have "pure sine wave" inverter? Please show it's output waveform on the scope so we all know what you have.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 18, 2017, 05:22:44 pm
content: Quoteno issue . I hope to know additional possibilities .Q.Will the driver less LED help me to cut power usage

author: ogden
author_rank: Super Contributor
timestamp: November 18, 2017, 06:39:22 pm
content: Quote from: dave_j_fan on November 18, 2017, 05:22:44 pmMost likely not. If driver-less bulbs would be universally more effective- they would dominate market, but this is not the case. All the hi-end LED bulbs are equipped with some kind of driver. Anyway you shall not rely on assumption. Better search internet for research/reviews which are comparing consumed power versus light output.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: November 18, 2017, 07:52:07 pm
content: Quotei was asking if i use AC MUX

author: ogden
author_rank: Super Contributor
timestamp: November 18, 2017, 08:25:07 pm
content: Quote from: dave_j_fan on November 18, 2017, 07:52:07 pmAC mux will unlikely change anything regarding various LED bulb efficiency. Frequency of supplied AC voltage instead can change a lot. If you use bulbs at much higher frequency - you are on your own. You shall get precision LUX meter and do your own efficiency measurements for various types of led bulbs.