hybridfree/eevblog-posts huggingface dataset:
EEVBlog Differential Probe and Keysight 3054T ? - Page 1
Forum section: electronics / beginners

author: Saskia
author_rank: Super Contributor
timestamp: December 01, 2019, 11:14:32 pm
content: Hi,I am looking for an "inexpensive" probe for looking at some switching PSUs and taking a couple of measurements. I got a quote for approximately 2k€ for a Keysight original. Since I am paying for this stuff out of my own pocket I am wondering if I should not just go for the probe that Dave is offering.This is the probe I am referring to:https://www.eevblog.com/product/hvp70/So I am asking a newbie question, just to make sure this is compatible and suitable for SMPS work:Will the probe be ok for use with the Keysight 3054T ? I guess it is, but I would like a positive confirmation before sending across the planet.Thanks a bundleSaskia

author: MarkL
author_rank: Unknown
timestamp: December 02, 2019, 04:17:05 pm
content: The HVP70 will work on any scope that has a 1Mohm input. I have one and use it on a Keysight 3104A. Works great.It's a good probe for SMPS work. Make sure you comply with the derating curve as shown in the HVP70 manual when working with high voltages/frequencies.

author: Saskia
author_rank: Super Contributor
timestamp: December 02, 2019, 09:12:42 pm
content: Thank you, highly appreciated. I just ordered it.
EEVblog DMM - Page 1
Forum section: electronics / beginners

author: xcvii
author_rank: Newbie
timestamp: December 04, 2017, 08:47:43 pm
content: I've just backed Dave's Kickstarter because why wouldn't I?!What did I just buy? How is it different to my $25 DMM? What good are data-logging and Bluetooth connectivity? How will this thing help me do better at my AVR projects and/or DIY guitar stompboxes?Explain like I'm five, I'm I total dunce in case it wasn't clear already!

author: iainwhite
author_rank: Unknown
timestamp: December 04, 2017, 09:38:45 pm
content: A few random thoughts:1) It has Cat III and UL, CE ratings that are trustworthy so it is going to be safe using on mains voltages. $25 meters are often not independently tested and the Cat ratings may be a work of fiction. (some, not all..)2) It has good input protection to deal with overloads on the input. Search "joeqsmith" who tests this sort of thing by zapping meters with high voltages. You can look at his youtube channel (listed below)3) It has a 50,000 count display which is likely 1 more decimal place than a $25 meter.4) Logging and bluetooth are handy for guys who want to measures trends over time - e.g. see how a device behaves over hours, days etc by taking repeated measurements. The 121GW can export such measurements in a spreadsheet for easy formatting & graphing.5) AVR and guitar boxes may not need a top-end meter, to be honest. However as your skills grow, you may attempt projects that need more accuracy or need features like simultaneous Voltage and Current measurements.Dave has done a couple videos on the design of the meter - look for EEVblog #929 and #931Joe Smith youtubehttps://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg

author: rstofer
author_rank: Super Contributor
timestamp: December 04, 2017, 11:16:52 pm
content: Here is a version of the User Manual (there will be a test later):http://www.eevblog.com/files/EEVblog-121GW-Manual.pdfAbout the only thing your old meter has in common with the 121GW is the fact that they both use batteries.There is a short video at the Kickstarter site that describes some of the features.

author: Kohanbash
author_rank: Regular Contributor
timestamp: December 05, 2017, 02:04:19 am
content: Quote from: xcvii on December 04, 2017, 08:47:43 pmI like things like this for putting the meter in an enclosure or out of reach and being able to view the data.The graphing is good for when you want to see things such as startup current in a motor, followed by the nominal current.The other exciting feature is the VA ability to view/log voltage and current at the same time.
EEVBlog uCurrent output to oscilloscope - Page 1
Forum section: electronics / beginners

author: veryevil
author_rank: Unknown
timestamp: November 06, 2012, 08:39:40 am
content: Hey, quick question. Can Dave's uCurrent be connected to an oscilloscope to see the current waveform? Does it not something in between or is it just not possible?Thanks

author: Rerouter
author_rank: Super Contributor
timestamp: November 06, 2012, 08:41:50 am
content: its an op amp amplifying the signal across a small resistance value, you may get some ringing on fast signals, but it should operate like any other op amp circuit,

author: deephaven
author_rank: Frequent Contributor
timestamp: November 06, 2012, 09:01:25 am
content: Yep, I've done that, it works a treat.

author: Simon
author_rank: Unknown
timestamp: November 06, 2012, 09:56:56 am
content: you will of course be limited by the bandwidth of the uCurrent so don't expect it to have perfect representation for higher frequencies, checking the specs of the opamp should tell you all you need to know.
EEVblog Videos - Capacitor Quality Question - Page 1
Forum section: electronics / beginners

author: jacksin_k
author_rank: Newbie
timestamp: December 16, 2015, 07:44:27 pm
content: Hi!I've recently discovered the EEVblog on YouTube and have been binge watching the episodes. It's great.As someone who is very new to electronics I'm curious why the quality of capacitor choice in a product is always a serious focus during teardown videos. I notice comparatively little time spent on discussing the brand of ICs and other components. Is capacitor quality so significant to a product that it always warrants such attention?Thanks for any help or clarification!-J

author: dadler
author_rank: Unknown
timestamp: December 16, 2015, 07:59:55 pm
content: They (aluminum electrolytic) are almost always the first components to fail, precipitated by heat exposure (internal or external) over time. ICs, when not subjected to ESD, are much more reliable in general.

author: jacksin_k
author_rank: Newbie
timestamp: December 16, 2015, 08:09:51 pm
content: Quote from: dadler on December 16, 2015, 07:59:55 pmThanks for the reply!So am I right in assuming (I guess this would be available in some datasheets?) that the mean time to failure is the major feature that distinguishes a high quality brand cap from a poor one?(edit for typo)

author: dadler
author_rank: Unknown
timestamp: December 16, 2015, 08:13:23 pm
content: Quote from: jacksin_k on December 16, 2015, 08:09:51 pmAhh, I think you have stumbled upon a quite contentious and opinion-filled topic:https://www.eevblog.com/forum/projects/capacitor-quality/

author: tautech
author_rank: Super Contributor
timestamp: December 16, 2015, 08:20:58 pm
content: Quote from: dadler on December 16, 2015, 08:13:23 pmQuite so.One that needs further exploration and discussion IMHO.

author: jacksin_k
author_rank: Newbie
timestamp: December 16, 2015, 08:39:06 pm
content: That's quite the thread but it definitely answers my question. Thanks for the link!
Effect of aerial on resonance? - Page 1
Forum section: electronics / beginners

author: aneevuser
author_rank: Frequent Contributor
timestamp: March 28, 2019, 10:09:40 am
content: I'm trying to make an AM radio.I have a LC tank circuit (currently based on a a couple of 1N5817s being used as varactors) which I can tune from 910 kHz to 1480 kHz when it is not connected to an aerial. I have L = 150 \$ \micro \$ H nominal and I think the varactors vary from about 70 pF to 180 pF roughly.I have 4 m of 0.6 mm single core wire which I'm using as (half of a) dipole aerial. When I connect it to the tank circuit, the resonant range is now 830 kHz to 1210 kHz.1) Is this magnitude of change expected?2) What exactly is causing this? Apparently an aerial with these dimensions should have an inductance of about 6 \$\micro\$ H so the effect on L should be small. Also if I assume that L is constant, then we should have:\$\frac{C_\text{low}}{C_\text{high}}=(\frac{f_\text{high}}{f_\text{low}})^2\$but that ratio varies from \$(930/810)^2 \approx 1.2\$ to \$(1480/1210)^2 \approx 1.5\$ over the resonant range, so it's not even constant.Can someone tell me what's going on?[apologies for dodgy latex - no idea what i'm screwing up]

author: vk6zgo
author_rank: Super Contributor
timestamp: March 28, 2019, 12:54:18 pm
content: Quote from: aneevuser on March 28, 2019, 10:09:40 amIt is not so much inductance, as capacitance between the antenna wire & the common side of the LC network.Traditionally, antennas are not connected straight across an LC circuit, but either a small coupling winding is used, or the inductor is tapped, with the antenna connected to one of the taps closest to the "cold"end of the coil.Real MF radio external antennas are many times larger than 4m, & yet radios work."Re inventing the wheel" is not as rewarding as many would think----It might be better to build a circuit that is known to work, then analyse that!

author: aneevuser
author_rank: Frequent Contributor
timestamp: March 28, 2019, 06:13:46 pm
content: Quote from: vk6zgo on March 28, 2019, 12:54:18 pmCould you explain what you mean by the common side. It's not clear to me.QuoteI see. Is this some kind of impedance matching technique?QuoteYes. I'm doing something wrong.QuoteI don't understand this. I'm definitely not reinventing any wheel. It's simply a piece of wire attached to the top of a tank circuit, pretty much like the crystal set radios that I used to make when I was a kid. I'll put up a diagram of the whole circuit later, when I get some time.
effect of frequency on filter output amplitude - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: April 21, 2013, 09:11:51 pm
content: I'm doing a PWM control circuit. The motor it will control will take the pwm signal and control the fan accordingly. Now I'm using an arduino and the standard frequency is 489 Hz whereas my motor manufacturer wants the PWM signal to be 50-150Hz.Looking at the motor datasheet the input circuitry is a low pass filter, 127K series resistor, 100nF parallel capacitor, cutoff frequency 12.5 Hz, so I'm guessing that anything like a 50-150Hz square wave will just produce a DC(ish) voltage output ? but what will happen if the frequency is higher ? the capacitor will behave like a resistor to the signal frequency so would vary it's impedience based on the frequency but that makes no sense because 50-150 is a 1-3 range so the smoothed voltage would vary by 3 times which would seriously upset the fan.So basically, I think I'm safe with the default arduino PWM frequency ? (This particular manufacturer is well known for churning out incorrect limitations on it's datasheets).
Effect of time constant of integrator on delta modulator operation - Page 1
Forum section: electronics / beginners

author: promach
author_rank: Frequent Contributor
timestamp: June 28, 2018, 04:18:23 am
content: For delta modulator with low pass RC filter as integrator , why it simply generates a periodic output at half of the clock frequency if the input peaks do not exceed the peaks of Vp ?Besides, how to derive sensitivity = Vdd * {1-exp[-Tck / (2RdCd ) ] } ?Note: the screenshot is taken fromhttps://cloudfront.escholarship.org/dist/prd/content/qt1pg6p6nb/qt1pg6p6nb.pdf#page=59
Effect of voltage and current on light bulb brightness - Page 1
Forum section: electronics / beginners

author: Legion
author_rank: Frequent Contributor
timestamp: February 13, 2014, 07:06:08 pm
content: I answered question 2 here:http://www.allaboutcircuits.com/worksheets/dc_p.htmlThe site's answer says the bulb shouldn't dim when the switch is closed since it's a parallel circuit and the voltage will remain the same (ignoring voltage sag).However, wouldn't the current division caused by the parallel circuit result in a significant change in bulb brightness (assuming the resistance in series with the switch is not significantly higher than the bulb's resistance)? Wouldn't the drop in current through the filament have a much more significant effect than voltage sag?

author: Simon
author_rank: Unknown
timestamp: February 13, 2014, 07:12:47 pm
content: Nothing will happen to change the brightness because the resistor is in parallel so both get the same voltage and as much current as required. Now if for example a tiny wire was being used then it would cause a resistance and the more current drawn the mre voltage drop on the wire so yes the bulb would dim.When i living in ital in a house with crappy wiring a plumber wanted to see if the electric boiler in the kitchen was working, so he turned on the kitchen (incandescent) light and then turned on and off the heater checking for a slight dimming of the light, this was because the wiring was so poor that a 10A load next to a 0.05A light bulb did make a difference but then i think question 2 is theoretical and not dealing with the practicalities of wire supplying the power

author: Legion
author_rank: Frequent Contributor
timestamp: February 13, 2014, 07:28:41 pm
content: Does this mean then that total circuit current will increase, but the current through the light bulb will remain constant?

author: c4757p
author_rank: Super Contributor
timestamp: February 13, 2014, 07:31:57 pm
content: Quote from: Simon on February 13, 2014, 07:12:47 pmDoes British wiringnotdo this? I would always expect flicking a 10A load on and off to visibly dim nearby lamps.

author: Simon
author_rank: Unknown
timestamp: February 13, 2014, 07:33:45 pm
content: I don't know, I've not used an electric heater near an incandescant bulb since i was back in the UK, the wiring in that particular house was really crap, it was like old 2 core speaker wire.

author: Hideki
author_rank: Frequent Contributor
timestamp: February 13, 2014, 07:35:15 pm
content: Since nothing else is specified... with perfect wire and voltage source you could in theory run additional giga-tera-peta-amperes through the switch and the bulb would still be as bright as before.As long as the voltage across the bulb is constant, the current will also remain constant.If you consider that real wires and batteries have a resistance greater than zero, then switching in the resistance will have some effect. It's still plain old Ohms law, except there now some additional resistance that previously wasn't accounted for.
Effects of Opamp Loading? - Page 1
Forum section: electronics / beginners

author: Shredhead
author_rank: Regular Contributor
timestamp: May 23, 2014, 04:22:17 pm
content: Hi guys,Someone warned me recently about picking too small of resistor values to put into op amp buffer circuits. He cautioned against "loading" the op amp.I don't know what that means. What would the effects of that translate to in an audio circuit? Increased THD, clipping or something like that?

author: retrolefty
author_rank: Super Contributor
timestamp: May 23, 2014, 04:40:09 pm
content: Certainly could. All opamps have some finite output current limit value where exceeding it will cause problems and/or specification degradation.

author: David Hess
author_rank: Super Contributor
timestamp: June 01, 2014, 05:35:06 am
content: Excessive loading will degrade the precision of the operational amplifier via both heating of the IC and lower open loop gain. If this is a problem, then adding a buffer stage to the output but inside the feedback loop can help.
efficiency in boost converters - Page 1
Forum section: electronics / beginners

author: volyaire
author_rank: Contributor
timestamp: January 21, 2018, 10:18:59 pm
content: I made a boost circuit using the LMR 64010 chip to boost 7.5v to 44v at only 3mA. It works well but consumes 41mA from the 7.5v battery which is way too much. My question is if I increased the value of the 10uH inductor to say 20uH or more will it improve the efficiency of the circuit? If I had some spare inductors I would test it myself, but I haven't.

author: Zero999
author_rank: Super Contributor
timestamp: January 21, 2018, 11:29:10 pm
content: It might help, as long as it has an equal or lower ESR.Extrapolating the efficiency curves on the data sheet, 43% seems similar to what you should expect from this IC, at the input/output voltage and current you describe.http://www.ti.com/lit/ds/snvs736b/snvs736b.pdfWithout a transformer, 7.5V to 44V requires a duty cycle of >83% so you shouldn't expect great efficiency, but it's possible to get better than this. You need a boost converted designed for lower current operation.

author: soubitos
author_rank: Frequent Contributor
timestamp: January 22, 2018, 12:07:34 am
content: Quote from: Hero999 on January 21, 2018, 11:29:10 pmDoing some research on boost ic's myself lately, i realized that in current draw under certain levels, most ic's performances drop significantly

author: Paul Price
author_rank: Super Contributor
timestamp: January 22, 2018, 03:25:18 am
content: This boost chip LMR 64010 spec shows a max output voltage of 40V and the OP is attempting to get 44V out.

author: volyaire
author_rank: Contributor
timestamp: January 22, 2018, 03:42:04 am
content: I am getting 44v out

author: ocset
author_rank: Super Contributor
timestamp: January 22, 2018, 06:25:22 am
content: Yes youre stressing lmr64010 and shouldnt use it....pretty much all practical smps are very inefficient when at low power.Also, the switching frequency is 1.6MHz which wont help......though i assume it acts in burst mode at your low power leve.Also, i am looking for the bias power draw of the chiphttp://www.ti.com/lit/ds/snvs736b/snvs736b.pdf..oh its only 3ma...so i would put it down to the high f(sw) and the fact your overstressing it and could be putting much leakage current through the internal fet.....also, the operation at low power level.

author: soubitos
author_rank: Frequent Contributor
timestamp: January 22, 2018, 10:05:30 am
content: It also doesnt help when you have a very low starting voltage.. the fact the chips CAN boost say from 5 top 20V doesnt mean they will be efficient at such setting... I use MT3608 powered from 1S lithium batteries... whith fully charged battery and output at 5-9V there is no problem drawing 1A (chip is spec'ed up to 2A)... doing the same at 12 V is trickier, chip starts heating up ... over 12V efficiency drops further and you can draw 200-500mA up to 15V maybe but its best not to stress it so far... I think at 24V (from 4.2V) you can draw as much as 50-100mA continuously but its still hot... I am not an expert per se, just sharing my experience!
Efficient 0.6-3.3V regulator for small dc motor. - Page 1
Forum section: electronics / beginners

author: DanioIO
author_rank: Contributor
timestamp: May 01, 2015, 08:15:29 pm
content: Hi,I need a digitally controlled 0.6-3.3V regulator to drive a dc motor, the output current will be 200mA max. Does anyone know a small footprint digiatlly controled regulator? I found only a LTC3447 which can output max. 2.05V. The regulator should work with 3.3V supply.Can i use a op amp with sufficient output current, i would drive it using PWM from a microcontroller but how efficient will the op amp be in this configuration?Any other solutions?

author: Seekonk
author_rank: Super Contributor
timestamp: May 01, 2015, 08:20:00 pm
content: I would go with full voltage and use duty cycle to control speed.
Efficient adjustable high voltage signal from mcu - Page 1
Forum section: electronics / beginners

author: DominicusPlatus
author_rank: Newbie
timestamp: August 17, 2014, 02:11:44 pm
content: HiI would like to implement adjustable voltage amplifier for fixed output to external devices. I'm just starting to learn analog circuits and I wanted to ask if my approach to this is correct and if there are any better. I decied to use interter opamp amplifying voltage supplied from capacitor charged by microcontroller. To controll 'on time' I set-up mosfet to pull the capacitor down again. But there are 2 issues with this :1. It requires two pins from MCU : 1 for cap charging , second for switching it OFF2. Off time is long ( ~4ms @ <3V3 100nF )Schematic and simulation output in attachement. ( Vpulse is used to simulate microcontroller digital output )I was thinking of using high-frequency op-amp with MCU PWM + Low pass filter but Im not sure itd be good to relly on opamp cap discharge for precision and MCU side itd require more computation.Is there any cost-effective way to have the same functionality with possibly better off-time ?Thanks
EFM32 Zero Gecko no gpio output but the bootloader is working - Page 1
Forum section: electronics / beginners

author: DanioIO
author_rank: Contributor
timestamp: December 06, 2014, 08:21:13 pm
content: Hi,I have a problem with Zero Gecko microcontroller, I can start the bootloader and program my ic but i dont see any output on gpio. I even check the power consumption of the ic using a simple 10Ohm shunt resistor and the power consumption profile is changing with time showing me that the ic is initializing and then going into sleep mode to be awaken in 500ms, but nothing on the gpio output. The code is working on my other boards, i also tried to solder others ic and they have the same problem.I attached my PCB layout I think the problem must be there.

author: jancumps
author_rank: Unknown
timestamp: December 06, 2014, 08:54:57 pm
content: You need to start one of the timers to make GPIO working. I'll check the code needed...

author: jancumps
author_rank: Unknown
timestamp: December 06, 2014, 08:58:20 pm
content: NEVERMIND, I see you had attached your code after posting this, and you're already calling the clock...CHIP_Init();/* Enable clock for GPIO */CMU_ClockEnable(cmuClock_GPIO, true);/* Configure LED pin as push/pull output */GPIO_PinModeSet(gpioPortC, 10, gpioModePushPull , 0);If you use SimplicityStudio, it's explained in application note (tutorial) TM007.

author: jancumps
author_rank: Unknown
timestamp: December 06, 2014, 09:21:32 pm
content: I've just tried your source on my ZG starter kit (replacing your 4 IOs with 1: PortC pin 10), and it works.
EFT,ESD AND FTB TEST - Page 1
Forum section: electronics / beginners

author: kumar
author_rank: Contributor
timestamp: August 10, 2013, 07:33:30 am
content: Does any one know about these tests?Are they performed through the power cord of the instrument or even the data cables?I want to select proper TVS diode for protecting the sensitive circuit, so can any one please tell me how to calculate the voltage and wattage generated across the TVS diode during these tests? ( For ex: how much voltage may be generated across TVS diode during a 8KV test )Also in many datasheets the reverse standoff voltage ( RSV ) has a min and max value. As I understand, the TVS diode breaks down if the voltage across it exceeds the RSV. In that case only the min RSV may be required. So what is the reason behind mentioning the max. RSV?
efuse and PWN signal - Page 1
Forum section: electronics / beginners

author: Tantalum
author_rank: Regular Contributor
timestamp: December 18, 2020, 07:50:11 am
content: HelloI wanted to switch on/off a load with a mosfet. The transistor would be driven by a TPS2492 efuse, but I have a question.Can I also turn it on/off with a pwm (somewhere between 1-100khz) on the UVEN pin of the efuse for led dimming purposes?Thank you
Egale And ZIF socket PROBLEM! - Page 1
Forum section: electronics / beginners

author: harindugamlath
author_rank: Newbie
timestamp: May 02, 2014, 12:35:04 am
content: Hi, This is my first post in EEVblog. Very recently I discovered your great site and I'm a fan since.I have a little question, I tried to find what is causing this unexpected behavior in Eagle but I couldn't.The other day I was designing a demo board PCB for PIC16F877A. The problem came with the two vss and vdd pairs in the PIC. google said that it is good practice to supply power to all the vss and vdd pins. So I did.Now here's what happend. I was using this 40 pin ZIF socket.This what my schematic looks like.This is what happens in the Board!Now I tried few things like removing 5v and GND and connecting them directly to where the supply starts. But nothing helped.Now when I remove the connection from one side, say 31 and 32 pins. This is what happens. It happens other way around also.Am I doing something wrong here??Can you guys explain what is happening??

author: rexxar
author_rank: Frequent Contributor
timestamp: May 02, 2014, 01:18:31 am
content: It looks like your ratlines are just laid out in a non-optimal way. If you follow the ratlines from C4, you can see that they go all the way around the the voltage reg, then over to C5, and then C5 has ratlines to 31/32and11/12.Electrically, it's fine, but it just looks funny. In DipTrace, I can hit F12, and it will optimize the ratlines, Eagle almost certainly has something similar.

author: harindugamlath
author_rank: Newbie
timestamp: May 02, 2014, 01:30:45 am
content: Quote from: rexxar on May 02, 2014, 01:18:31 amMany thanks!I think i just made classic stupid mistake.But i can't believe I didn't optimized the ratlines. may be from exhaustion yesterday night. Many thanks it did the trick. I was just about to modify the ZIF socket in the library. Still I can't believe what happend. Many thanks.

author: rexxar
author_rank: Frequent Contributor
timestamp: May 02, 2014, 02:21:50 am
content: Quote from: harindugamlath on May 02, 2014, 01:30:45 amNo worries!We all make rookie mistakes at some point

author: Steffen
author_rank: Regular Contributor
timestamp: May 03, 2014, 10:56:08 am
content: Just type "ratsnest" in Eagle (and hit Enter) from time to time, it optimizes airwires and renders polygons. Help ratsnest.

author: FrankBuss
author_rank: Unknown
timestamp: May 04, 2014, 04:55:23 pm
content: Quote from: Steffen on May 03, 2014, 10:56:08 amOr just click on the cross with the five green points on the bottom left on the toolbar.And another good trick when routing the board manually: Sometimes even after ratsnest the air wires are not at the position where you want to route a wire, if for example you want to route from an existing routed trace. Then just hold down the ctrl key while clicking on the routed trace and then you can route from this point.
Egg timer project help. - Page 1
Forum section: electronics / beginners

author: MarkusAnd
author_rank: Contributor
timestamp: April 02, 2019, 08:20:29 am
content: Hello!As a newbie, I thought a nice project for me is to design an egg timer. I was thinking of using two 555-timers. So my plan was to use the second one in monostable mode so that it could be triggered by the output from the first one. As a switch, I'm using the 2n2222a transistor which will connect ground to pin2.So, in short, the first 555timer outputs a signal to the base of the transistor which connects pin2 of the second 555timer to ground. The second timer then outputs a signal to a buzzer.The problem I'm having is that when I'm testing the circuit for the second timer with an LED, the LED is on even though I'm not feeding a voltage to the base of the transistor. In the circuit I have attached I'm using a pushbutton attached to VCC to act as the signal from another timer. What am I doing wrong?//MAEDIT:I figured it out!

author: Zero999
author_rank: Super Contributor
timestamp: April 02, 2019, 11:56:13 am
content: The LED is reverse biased, so will never light, which I take it is a drawing error.Pin 2 should have a pull-up resistor. It will no doubt work without one, but just letting it float makes the circuit susceptible to false triggering, due to noise pick-up.
EI Transformer design theory questions - Page 1
Forum section: electronics / beginners

author: Mephitus
author_rank: Regular Contributor
timestamp: December 30, 2016, 05:12:14 pm
content: I have been reading several different books/references about transformer design and theory. So far the hardest part has been with trudging through the math like the horse in The Never Ending Story. But I'm slowly making progress with that. I am wondering about a few design factors in regards to laminated silicon steel E-I transformers that I cant find any specifics on (or may have honestly missed).1: The dielectric medium that isolates the laminations, how much of an effect does its conductive resistance have?2: When it comes to windings, what kind of difference is there between primary and secondary being stacked one on the other vs isolated/separate windings? (See attached pic)3: Alternating each layer orientation |3 to E| vs all layers in the same orientation. What are the practical differences or considerations for this?

author: PChi
author_rank: Frequent Contributor
timestamp: December 30, 2016, 06:53:32 pm
content: Quote from: Mephitus on December 30, 2016, 05:12:14 pm1: At 50 Hz just the scale / finish on the laminations was considered to be adequate to prevent significant eddy currents and this appeared to be the case.2: The leakage inductance is determined by the flux linkage between the windings with the isolated/separate windings having a higher leakage inductance (probably). At 50 Hz it isn't usually a problem. However if it's 400 Hz then it's time to check.3: Alternating the E/I s hopefully minimises the air gap in the magnetic circuit so maximises the magnetising inductance so reduces the transformer no load current. Though I guess in practice if they were all the same way round and care was taken to minimise the air gap there may be little difference.

author: Zero999
author_rank: Super Contributor
timestamp: December 31, 2016, 10:44:29 am
content: The configuration shown on the left will have better coupling between the primary and secondary but more capacitance between the windings and it's more difficult to isolate the two coils. It's more common when the secondary is connected to earth anyway so the capacitance is less of a problem.The diagram on the right, well have slightly poorer coupling but less capacitance and it's easier to isolate the two windings. Quite often the two windings will be wound on separate bobbins. This is commonly used in small mains transformers with no connection to earth on the secondary.
Eimac 3-1000z as night light (really) - Page 1
Forum section: electronics / beginners

author: blowfish
author_rank: Newbie
timestamp: September 26, 2022, 07:00:10 pm
content: I've got a real desire to turn an Eimac 3-1000z into a dresser-mounted night light.I've seen this video on Youtubeand the purple glow from that thing is mesmerizing (to me).My question: what does it take to make that thing glow like that? I've checked the specs and it says the heater voltage is 8 volts and 20 amps. Is that all I would have to do to get that thing to glow? Just supply it with 8 volts at up to 20 amps ?In the Youtube video, he's got it on standby. He mentions a plate voltage of 3500 volts.I would appreciate any thoughts or suggestions.Thanks.

author: The Doktor
author_rank: Regular Contributor
timestamp: September 26, 2022, 07:16:32 pm
content: The heater voltage is all it takes to get the yellowish white filament glow, please note that's 160 watts for a night light, giving off lots of heat. The bluish glow will take a few KV and at least several tens of ma, more likely over 100ma. It is a beautiful display piece, but expensive to run and lethal if someone makes contact. Use extreme caution.Ed

author: james_s
author_rank: Super Contributor
timestamp: September 26, 2022, 07:24:08 pm
content: Is there actually a purple glow or is that just an artifact of the camera? Camera sensors are sensitive to IR so even with the filter any object that is glowing red will appear a purplish color to most cameras. 160 Watts to drive the filament is an incredibly large amount for a nightlight. I could run the majority of the (LED) lights in my house for that much power.

author: jonpaul
author_rank: Super Contributor
timestamp: September 26, 2022, 07:38:53 pm
content: The visible light émissions are misculle the, 99.5% is InfraredBlue of energized TX tube is soft x-rays exciting the glass fluorescence, if Vplate> 10 kV.Most TX tube lamps place à conventional bulbsocket on the plate cap, and /or place LEDs under the glass envelope at the base or socketJon

author: gbaddeley
author_rank: Regular Contributor
timestamp: September 27, 2022, 12:47:28 pm
content: I’ve got two 3-1000Z. One on my side of bed, the other on the wife’s side? Maybe not during summer.
EL - Wire Inverter - Page 1
Forum section: electronics / beginners

author: MynameIsRain
author_rank: Newbie
timestamp: July 07, 2015, 03:08:59 am
content: Hello!! I would like to build a 12v EL - Wire inverter but i don't have any idea what component should i use. I search in the internet all i see is they use 555 timer and CD4047.There is out in market of 12v EL - Wire Inverter but i want to make my own.Thanks

author: Mr.B
author_rank: Unknown
timestamp: July 07, 2015, 04:26:09 am
content: Someone round here, cannot remember who, has a posting signature that reads something like this..."If you can buy it for $2 off ebay, why would you design and build it?"

author: tron9000
author_rank: Frequent Contributor
timestamp: July 07, 2015, 07:56:22 am
content: Quote from: Mr.B on July 07, 2015, 04:26:09 amto learn possibly? why else would he ask?Quote from: MynameIsRain on July 07, 2015, 03:08:59 amFor a beginner I would use those designs you have found, least then you have some idea of how it works. They are easy to obtain and cheap to replace if you go wrong.

author: richard.cs
author_rank: Super Contributor
timestamp: July 07, 2015, 12:40:24 pm
content: I have made an EL inverter. My design wasn't all that elegant, it used a conventional 240V : 12 V (centre tapped) potted PCB mount transformer in reverse running at about 120 Hz. Simple two transistor astable driving a pair of output transistors. If I were doing it again I'd use a binary divider to generate the complementary drive signals to ensure 50:50 duty cycle and probably run at much higher frequency with a ferrite transformer. The 100 Hz approach works but needs a lot more voltage to push enough current through the EL wire, which is essentially a lossy capacitor.

author: Zero999
author_rank: Super Contributor
timestamp: July 07, 2015, 10:22:20 pm
content: https://www.sparkfun.com/products/10469https://www.adafruit.com/products/448

author: Whales
author_rank: Super Contributor
timestamp: July 07, 2015, 11:30:11 pm
content: @MynameIsRainWhat is wrong with the designs using the parts you mention? I'm not sure what you are after when I read your question.Also be wary of the hazards of high voltages made by EL inverters. If this is your first ever electronics project I would suggest having some fun with a few other circuits first, and get the help of someone who is confident working on high voltage items so they can give you some advice and tips when working on it.

author: MynameIsRain
author_rank: Newbie
timestamp: July 08, 2015, 01:43:36 am
content: actually i want to lighten up an EL wire about 10 m or longer. if i design a 12v El wire inverter i need a high frequency and high voltage for lighten up the longer EL wire??

author: Whales
author_rank: Super Contributor
timestamp: July 08, 2015, 06:48:48 am
content: Quote from: MynameIsRain on July 08, 2015, 01:43:36 amEL wire is strange when you add longer lengths. According tothis sourcethe driver needs to deliver more current to maintain the driving frequency (and therefore brightness) but I'm not sure what the voltage does.Again, this sounds like a pretty heavy project. I'd advise buying a pre-existing solution for this.
ELEC-TROL VPS6A05B10 (Wisdom of the Ancients ) - Page 1
Forum section: electronics / beginners

author: KubaSO
author_rank: Contributor
timestamp: June 17, 2025, 10:05:11 am
content: Circa 2006 someone had a question about ELEC-TROL part VPS6A05B10:https://www.electro-tech-online.com/threads/electrol-vps6a0b510.24676/I thought I would answer it more comprehensively, in the spirit of making Internet a better placehttps://xkcd.com/979/I'm using this part in a relay computer, got 50 of them, date code 8847, nice parts. I use them as output enable gates for connecting modules to buses in a relay computer.30mm x 23mm x 9.5mm, through-hole potted package, 12 out of 14 pins populated,hex-pole single-throw reed relay - with 6 independent form-A (normally open) contacts,single 5V, 340mW coil, 73Ω series resistance, 3V cut-in, 1V cut-out, Vmax around 6.3Vno suppression diode built-incoil inductance 24mH @ 1kHz, Q=1.8, time constant 𝜏=30μs i.e. speed limited mechanically onlyoperate time 0.3ms + <0.15ms bouncerelease time 0.3ms, no bounceoperate/release times measured with a 50Ω, 5V source connected across the coilcoil on pins 1-2, contacts are 3-4, 5-6, 7-8, 9-10, 11-12for fast operation, use a RC snubber set up for the field to decay in 3-4 cycles of oscillation - this also degausses the armature and keeps it fastFast little thing.
Electret microphone circuit - Page 1
Forum section: electronics / beginners

author: UltraRC
author_rank: Contributor
timestamp: May 11, 2016, 05:25:04 am
content: So lately I have been experimenting with electret microphone circuits.Questions:- What voltages should/can I run my microphone circuit off, and what are the effects of changing this?- What are the effects of changing the resistor value of R1 and R2?Any help would be great, and if you have any other info you want to share that would be good as well.

author: EEVblog
author_rank: Unknown
timestamp: May 11, 2016, 05:32:37 am
content: https://www.youtube.com/playlist?list=PLvOlSehNtuHv98KUcud260yJBRQngBKiw

author: UltraRC
author_rank: Contributor
timestamp: May 11, 2016, 06:40:12 am
content: Thank you!
Electric Cars\Bikes - Page 1
Forum section: electronics / beginners

author: StrayCitizen
author_rank: Newbie
timestamp: November 26, 2015, 10:00:18 am
content: Hi Guys Hows ThingsIm Building A Electric Trike With A 48V DC 1KW MotorCouple Things I Need To Know And If You Can Help That Will Be Great1. Can I Over Volt The Motor To 50V My Controller Can Handle 55V Regulated Power2. I'am Pumping Through 60a Through A Step-up Converter And Wonder What Size Caps I Need To Regulate The Power, I Would You Voltage Regulator Devices But Cant Find One With Thats 100w or Regulate 50v3. Iv'e Made A Basic Circuit Could You Guys Proof Read It For Me, Electronic Math Is Horrible For MeThank For Your HelpPlease Note Im Using A deep Cycle Marine Battery With A Computer PSU 650w To Charge The Batteries.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: November 26, 2015, 11:14:02 am
content: I think you are going to have to do a better job explaining the scematics... It might just be me, but all I'm seeing is a bunch of coils and diodes and I have no clue why you need so many of them in parralell, or what they are even supposed to do. Also, I don't seem to understand what you have all the ideal AC and current sources for... not to mention that if I'm reading it right, in the last schematic you are connecting the 12V and 50V rail to the same point, which won't work...I would like to add that your motor will probably be fine with 50V, but I don't really see the point of pushing it past spec...

author: StrayCitizen
author_rank: Newbie
timestamp: November 26, 2015, 12:07:11 pm
content: Its A Capacitor Bank & Inductor To Regulate Current And VoltageThe One With The 2 Rails Are Switched Between 12v And 50v Through The Switching Filter BankHere Is A Updated One
Electric consuption for triphase dryer conveyor(with electric meter) - Page 1
Forum section: electronics / beginners

author: tlhsglm
author_rank: Contributor
timestamp: January 27, 2022, 05:28:22 pm
content: Hi dear friends,My friend's father have a dryer like below youtube video(video is not mine) . I will open it and put insulating materials. But i want to see how much it will effect electric consumption.Machine first heating up for half hours and then we are putting textiles to dry. i want to see electric consumption for like 6 hours. Because -as you know- motor is keeps running but heaters not open or at same power for everytime, i have to see consumption for a while.I have done lot of arduino projects and some monophaze projects but none triphaze so i want to do it right and safe.Kindly can you please help on below?I want to see how much electricty this machine consumpts in 1 day. I have uni-t ut89x multimeter but im not sure how much amps machine consumps. and since i want to see it's one day consumption i had and idea that i pictured below;Can electric meter mislead me? What do you think about my solution?https://www.photobox.co.uk/my/photo/full?photo_id=504499003076

author: tlhsglm
author_rank: Contributor
timestamp: January 27, 2022, 09:47:14 pm
content: please

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: January 28, 2022, 03:47:34 pm
content: I would recommend you use a proper power logger. Fluke 1748 for example. They are widely available for rent.

author: Siwastaja
author_rank: Super Contributor
timestamp: January 28, 2022, 04:14:14 pm
content: Or just a normal electricity meter (energy meter). Available everywhere. Intended for billing, accurate within a few %. Cost for a 3-phase model is something around $100, though. Maybe you could find a used unit, even an old mechanical.If you want actual logging, these have at least a blinking LED you can optically couple to, and many have open collector optoisolated pulse output for easy interfacing with any logging system. One pulse per Wh or similar.

author: tlhsglm
author_rank: Contributor
timestamp: January 28, 2022, 05:16:22 pm
content: thanks, my paint file at first message includes three phase billing energy meter i will use it

author: Siwastaja
author_rank: Super Contributor
timestamp: January 28, 2022, 06:11:21 pm
content: The link does not work and "photobox.co.uk" has broken server configuration not returning 404/403/whatever the error is, but instead silently redirecting to front page.
Electric fence teardown, trying to understand how it works - Page 1
Forum section: electronics / beginners

author: tigrou
author_rank: Regular Contributor
timestamp: May 21, 2024, 11:18:17 am
content: I have open an old electric fence for general inspection. The capacitor connectors are rusty and it probably need to be replaced.I would like to understand how it works.Inside there is a big transformer, a capacitor and this PCB :The white connections on the top left are as follow : mains / capacitor / transformer.Transformer output goes directly to electric fence output (claimed to be 10000V).Questions : why is there a need of a big 220V capacitor ? to store energy and release it later, while the transformer is "ON" and doing his job ? Isn't mains enough ?I would have expected the capacitor to store rectified transformer output, and to release in one go but that's not the case here.It's also unclear what it the role of the 2 diodes and the 4 mosfet.Probably to implement a timer circuit (that give a pulse every second). Potentiometers are probably used to adjust this.I will try do to some tracing and draw proper circuit when if I have some time.

author: madires
author_rank: Super Contributor
timestamp: May 21, 2024, 02:09:31 pm
content: Quote from: tigrou on May 21, 2024, 11:18:17 amYep! That's the best way to understand how the circuit works. And it will answer your questions.

author: tigrou
author_rank: Regular Contributor
timestamp: May 21, 2024, 04:03:33 pm
content: I think I got how it works : the capacitor is charged with DC (that's why you need diodes). Then once it's ready, it get dumped into the transformer using thyristors (so those are not MOSFETs).I expected the transformer to only work with AC but for a short pulse, it work as well. This is probably similar to "capacitor discharge ignition" used in some vehicles.

author: aliarifat794
author_rank: Regular Contributor
timestamp: May 21, 2024, 05:57:25 pm
content: In an electric fence controller, storing rectified transformer output directly for later use isn't practical. The high-voltage side needs to be isolated and controlled precisely so that it can create consistent, timed pulses.

author: tautech
author_rank: Super Contributor
timestamp: May 24, 2024, 08:16:22 am
content: Quote from: tigrou on May 21, 2024, 04:03:33 pmCorrect.It must be done this way for correct timing and limiting output as their are laws that limit output so to protect innocent individuals from serious injury and/or death.The earliest units were electromechanical and only ran from LA batteries in the days before semiconductors and required occasional maintenance of the contact points.
Electric motor and no load speed - Page 1
Forum section: electronics / beginners

author: bonzer
author_rank: Regular Contributor
timestamp: November 27, 2019, 07:46:17 pm
content: Hello everyone! Please help me to figure out the concept of no load speed.I find that from mathematical point of view we have no torque when there's no load so the motor needs no current to work. For example a SPM motor , without a current we still have a speed due to the voltage applied and the permanent magnet flux linkage and considering no resistance it's equal to back emf.V= ΛmωI'm new into this but what I think is that the motor needs always a current to work because of its physical structure it is a mechanical load itself. Maybe it's negligible compared to the currents it can work at with big loads.So I don't understand what is this information used for? Is this an approximation?
Electric motor datasheet puzzle? - Page 1
Forum section: electronics / beginners

author: electrolux
author_rank: Regular Contributor
timestamp: July 05, 2015, 11:17:01 am
content: In the datasheethttp://media.wix.com/ugd/28f2e3_421a99745acf461794f51708937c9994.pdffor the AMR Dual Corehttp://www.amracinginc.com/#!dual-core/ct07if you look at the two LAST power curves in the list are the same at: Constant 310Arms 600VDC. WHY?

author: amyk
author_rank: Super Contributor
timestamp: July 05, 2015, 12:18:27 pm
content: Look at the units on the left.It seems they want you to figure out which one is which from the general shape, which you should be able to.

author: electrolux
author_rank: Regular Contributor
timestamp: July 05, 2015, 04:16:57 pm
content: Ok......Got it!
Electric panel and MCB - Page 1
Forum section: electronics / beginners

author: mike_mike
author_rank: Super Contributor
timestamp: June 15, 2022, 02:53:24 pm
content: Hello ! I equipped an old electric panel with some new MCB's. I used 25A and 2 poles (2p) on the general, 1 pole and neutral (1p+N) for the rest of the panel: 4x 16A and 4x 10A for electrical outlets circuits and 3x 6A on the light bulbs circuits. All of them C curve.The earth arrangement is TNC.The mcb's that I used are Schneider Electric Easy9. I fed the mcb's from the bottom side and at the top side I connected the circuits.I made the following tests: I used a 4kW consumer at an C10 mcb and the mcb triggered in about a few seconds.The second test was to make a direct short circuit on the C10 mcb outlet, but instead of triggering only the C10 mcb, it also triggered the C25 mcb (the general 2p mcb). It is normal to trigger the 25A mcb instead of triggering only the C10 mcb ?

author: rstofer
author_rank: Super Contributor
timestamp: June 15, 2022, 03:34:02 pm
content: For a short circuit, timing is pretty much out the window. Basically, the instantaneous trip mechanism is a solenoid and it moves pretty fast.https://img.c3controls.com/image/upload/resources/c3controls-Understanding-Trip-Curves.pdf

author: bdunham7
author_rank: Super Contributor
timestamp: June 15, 2022, 03:43:46 pm
content: Quote from: mike_mike on June 15, 2022, 02:53:24 pmWith the magnetic trip there are two timings--the time it takes to set the trip mechanism irreversibly in motion and the time it actually takes to disconnect. The first is very short, the second is the clearing time that you usually see listed and is much longer. What happens when you short two MCBs in series is that the first one starts the trip process, but that doesn't complete immediately. During the time between the initialization of the trip and actual disconnect, current is still flowing and the second MCB may start its trip process. After this point, even if the first one clears (disconnects) the second one will continue its mechanical disconnect process.

author: tepalia02
author_rank: Regular Contributor
timestamp: June 16, 2022, 10:00:23 am
content: Quote from: bdunham7 on June 15, 2022, 03:43:46 pmThank you so much for the clarification.