hybridfree/eevblog-posts huggingface dataset:
Suggestions wanted for "Soft Latching Power Switch" ICs - Page 1
Forum section: electronics / beginners

author: Manuauto
author_rank: Newbie
timestamp: July 08, 2018, 07:51:13 pm
content: Hi,I'd appreciate any suggestions for cheap, available and preferably easy to useICswhich are designed to be used in alatching On/Off Power Button circuit.I am aware that Dave made a video on this topic, describing how this function can be achieved with jelly-bean parts.This circuit has it's flaws and isn't exactly very (noob-) user friendly.While looking for something a bit more practical and "advanced", I came across the Henry HR810:https://www.aliexpress.com/item/6A-DC-3V-3-3V-3-7V-5V-Electronic-Switch-Latch-Bistable-Self-locking-Trigger-Board/32795061369.htmlThe module works great.Sadly I cannot find a way to purchase the IC cheaply without the mosfet etc.Other requirements:- low voltage operation (battery power, singe cell Li-Ion)- low quiescent current / low power consumption- low price(Aliexpress would be good because of the usually free shipping)!Less important- maybe even a built-in mosfet- reasonably large footprint, maybe even "DIP-friendly"I am not asking for the "perfect solution" and am very happy about simple hints and general ideas as to which components could be used.When searching the internet for suitable parts, I came across several Ti parts which weren't available on Aliexpress. Digikey has them (TPS3422) but I'd have to pay shipping...Thanks in advance!

author: Zero999
author_rank: Super Contributor
timestamp: July 09, 2018, 08:06:49 am
content: Look at flip-flop ICs, such as the 74HC74, which contain two. They're also available in single, to save space, but they're SMT only.

author: Manuauto
author_rank: Newbie
timestamp: July 09, 2018, 09:25:26 am
content: Thanks for the suggestion. I came across several circuits with flip-flop ICs when looking for ways to implement this function.I thought, that they are not exactly "zero-power when off" but actually they seem to be a viable option!

author: tautech
author_rank: Super Contributor
timestamp: July 09, 2018, 11:00:32 am
content: 4013 is another option just check the datasheets for low voltage operation and select a low gate voltage MOSFET that'll work at the voltage you use.CD varieties might just work or you could be better off with an HEF version.

author: Zero999
author_rank: Super Contributor
timestamp: July 09, 2018, 11:10:14 am
content: Quote from: Manuauto on July 09, 2018, 09:25:26 amThere really is no such thing as zero power when off. Any circuit will consume a tiny amount of power.The NLX1 will consume 1µA worst case (it'll probably be much less than that, around 100nA), at an operating temperature of less than 25°C and less than 10µA, at an ambient temperature of 125°C. It's very difficult to beat that.https://assets.nexperia.com/documents/data-sheet/74LVC1G74.pdf
Suggestions required for small embedded computer - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: June 23, 2016, 04:04:40 pm
content: 1. I need a camera interface which some audio output. Image taken has to be processed inside & its contents to be spoken out.Earlier I thought of using raspberry pi as it has camera & audio out, then internally OpenCV can be used.But it has large form factor, I need something smaller. Also raspberry pi has large footprint & major problem is its current consumption also.I need to tailor down my application for this task only.2. Any suggestions on it which board can be used?

author: ebclr
author_rank: Super Contributor
timestamp: June 23, 2016, 04:19:05 pm
content: Do you know pi zero ?What about arducam ?
Sugon t26 - Page 1
Forum section: electronics / beginners

author: Shoubhik saha
author_rank: Newbie
timestamp: January 08, 2021, 10:27:58 pm
content: Recently there's been an soldering station that's doing round the YouTube namely sugon t26 (also a newer version t26d) this iron seems to use jbc tips and the handle t210 kind. It's cost around 115-150 usd (depending on where you stay) so just wanted to ask if anyone has any experience with this or can anyone give me any opinion about it. . And if it will be compatible with t245 handle? Are they any good? Please replyhttps://youtu.be/nChr8iSgAQwhttps://youtu.be/UACZMu7o06khttps://www.vipfixphone.com/products/sugon-t26d-lead-free-original-soldering-station-2s-rapid-heating-up
Suitability for use - Page 1
Forum section: electronics / beginners

author: kcs
author_rank: Regular Contributor
timestamp: January 28, 2016, 11:33:18 am
content: Many manufacturer are stating that their parts should not be used in products where failure or malfunction could result in injuries or death. For example, NXP says:QuoteI could think of many scenarios where even the most simple electronic household equipment could cause injuries if it malfunctions. So, my question is - are manufacturers really following this guideline? If so, what parts do they use then? Is it really true that there are no NXP semiconductors, for example, in any medical device, vehicle etc.?

author: AndyC_772
author_rank: Super Contributor
timestamp: January 28, 2016, 11:48:16 am
content: It's all about liability and shifting responsibility.If failure of a component could, on its own, lead to a safety hazard, then any system which incorporates that component should be designed to fail safe. For example, if a microcontroller responsible for controlling a critical system locks up, the design might include a watchdog to reboot it, and should in any event end up in a safe condition if the reboot is unsuccessful.For something like a household appliance, the applicable safety standard implies the need to consider 'what if?' each component were to fail in the worst possible way. Certain design features may be required, such as physical isolation between the mains and any part which can be touched, so that even if a whole bunch of components were to fail short circuit, the fault would still not be able to electrocute anyone or start a fire.If you need greater reliability in any individual component, then suppliers might be able to provide it - but the price will go up dramatically, depending on the amount of testing, certification, and (especially) liability that tha supplier is expected to provide or accept.
Suitable adc bits/speed for photodiode - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: April 24, 2015, 06:47:34 am
content: 1. I have to design transimpedence amplifier(TIA) for monitoring photodiode in Fiber Coupled Diode Lasers.2. Opamp which i will use for TIA is MCP6491 , 3.3V powered.3. The input pulse for laser diode will be approx 1us.4. Now as far as I understand, this is time when photodiode will give ouput? (I don't know just a guess, don't understand how this pair works).5. If yes, then what speed/bits of adc should I choose.6. Any AN or website link for understanding the operation.7. The link that I have read are either of photodiode or laser. Don't know how this combination works or what will be output of photodiode when laser turns on?

author: Dago
author_rank: Frequent Contributor
timestamp: April 24, 2015, 06:59:02 am
content: http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem

author: mikerj
author_rank: Super Contributor
timestamp: April 24, 2015, 08:25:28 am
content: You haven't stated what you are actually trying to measure:Pulse amplitude (peak,rms etc?)Pulse width?Pulse shape (rise/fall times etc?)
Suitable IC for switch/multiplexing MCU pins for TFTs - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: August 09, 2016, 07:40:49 pm
content: In past I multiplexed UART with CD4052/3 IC, currently I'm in a situation where I want to multiplex 8 MCU pins for two different types of TFTs (at 3.3v).I want to know ICs who have 4 or 8 inputs and it can switch/multiplex outputs, please refer to attached image.
Suitable MOSFET substitute for HY1403 ?  - Page 1
Forum section: electronics / beginners

author: nonsubscriber
author_rank: Newbie
timestamp: May 23, 2023, 03:05:42 pm
content: Hi all.I am trying to read up what parameters I need to match but I'm finding myself confused. This is the output MOSFET for a 3D printer hot-end.https://www.alldatasheet.com/datasheet-pdf/pdf/1145823/HUAYI/HY1403D.htmlAnyone willing to help with some common parts that would work?Thanks!

author: nonsubscriber
author_rank: Newbie
timestamp: May 23, 2023, 03:21:27 pm
content: Looking at NTE2395https://www.nteinc.com/specs/2300to2399/pdf/nte2395.pdf

author: u666sa
author_rank: Frequent Contributor
timestamp: May 23, 2023, 03:56:56 pm
content: Well here is this transistor onthissite.Andhereare 20 to 30 analogs.They are also on aliexpress, if you don't mind waiting.

author: nonsubscriber
author_rank: Newbie
timestamp: May 23, 2023, 07:19:43 pm
content: Thanks. Yes shortly after I posted I found those resources as well.The only thing I have access to locally (want to solve the issue today,) is NTE. It's not on the match list in fact it's not even on that site at all but look close enough to me? NTE2395Anyone else?

author: nonsubscriber
author_rank: Newbie
timestamp: May 23, 2023, 10:04:21 pm
content: Well nothing went bang but the mosfet didn't work/no output.

author: nonsubscriber
author_rank: Newbie
timestamp: May 25, 2023, 04:11:50 am
content: Ahh so given that my TTL/gate pin is 3.3V makes sense that the NTE2395 didn't work as should be >4V to turn on.

author: videocam
author_rank: Newbie
timestamp: July 11, 2023, 11:46:34 pm
content: I use the 70T03GH
Suitable PMIC selection - Page 1
Forum section: electronics / beginners

author: boriskorbel
author_rank: Newbie
timestamp: January 08, 2020, 01:45:21 pm
content: Hello, I am looking for suitable PMIC circuits as my project is focused on solar energy harvesting with maximal power harvested around 81 mW. My energy source is an array of 24 parallel connected solar cells. As I was searching through many PMICs I found that many are suitable for solar cells only connected in series. Solar cells are attached on the helmet and are intended to power IMU with ESP32 that sends data via BLE, therefore I supposed there might be big current peaks while data transmission. Do you have any recommendations of specific PMIC for my requirements?Boris
Suitable power supply for Analysir's 10MHz OCXO frequency standard - Page 1
Forum section: electronics / beginners

author: Nozzer
author_rank: Contributor
timestamp: October 08, 2016, 05:28:49 pm
content: I recently bought the A option of Analysir's10MHz OCXO frequency standardon Tindie and was wondering if anyone can advise me of how to make a suitable power supply for it. I was thinking of a linear regulator circuit allowing me to use an existing plug in mains to 12vdc source.
Suitable power switch solution to be used - Page 1
Forum section: electronics / beginners

author: VEGETA
author_rank: Super Contributor
timestamp: September 10, 2021, 05:40:28 pm
content: Hello,I am designing something which uses enclosed PCB mounted AC-DC converter module. It is IRM-20-5 from Meanwell (I will use a similar one from Recom because it is better in noise\ripple)... which is 5v @ 20 watts. Expected maximum consumption is less than 20 but the idea is the same.I have 2 options:1- use a hardware power rocker switch on the AC side. Typically breaks or links the live terminal to the AC-DC module while the neutral is always connected. However, this is expensive to get since such switches go for not so cheap (design is already expensive) and it could make issues in terms of how to mount it on the board or maybe on the panel then hand solder it which requires extra effort and assembler might not do good...etc... etc.a cheap one is this:https://www.digikey.com/en/products/detail/e-switch/RA17131100/3778067but how to ensure panel mount one like this is sturdy and how to make enclosure cut for it? it will require hand soldering for sure, I don't prefer screw terminals. would these wires cause any issues in terms of EMI or noise?I like this one as well:https://www.digikey.com/en/products/detail/e-switch/RR11132211/37781162- use a soft-latching solution on the 5v DC side via N or P mosfets.This solutions allows me to use a small very cheap momentary push button which I used elsewhere, it is surface mount (can reach to top side of the assembly) and can be mounted so that it points out to the top of the enclosure. such mosfets are very cheap with low Rdson. It is used in laptops all the time. I have transistors and mosfets in the design already.the disadvantage in my opinion are these:A- the power module will always be on. it is most likely a flyback design, which means pulsing and so on will always be happening which is not good! I cannot use this method on AC side right?B- where to get the DC voltage from? the idea is that the entire circuit is off therefore no MCU can be powered all the time. I would need to make everything using the 5v rail so that it cuts 5v from the entire circuit.What solutions do you propose?
Suitable replacement for AT27C1024 IC - Page 1
Forum section: electronics / beginners

author: giosif
author_rank: Frequent Contributor
timestamp: October 08, 2022, 06:01:12 pm
content: Hi,I am looking for a suitable replacement for an Atmel AT27C1024 OTP EPROM IC in TSOP/VSOP-40 package, as it seems it's not that easy to find (let me know if you happen to have a spare one or know where to get one at a reasonable price).The replacement IC can be either EPROM (OTP or otherwise) or EEPROM and could have larger capacity (the AT27C1024 has 1Mbit - 64K x 16 - capacity), as long as the pinout is the same.Anyone has any suggestions, please?Thanks!

author: wraper
author_rank: Unknown
timestamp: October 08, 2022, 06:25:11 pm
content: You can still get one.https://www.utsource.net/itm/p/4142325.htmlEven though it says used, IME it likely will be NOS. There are a lot of suitable replacements including NOR FLASH like AT49F1024A, the issue is almost all of them are equally hard to buy in TSOP-40 package. And you need to spend a lot of time to search for all possible replacements and if you actually can buy them.

author: Benta
author_rank: Super Contributor
timestamp: October 08, 2022, 07:31:50 pm
content: I don't think many EPROMs/OTPROMs are used any more. I'd look to Flash replacements instead, better availability.

author: CaptDon
author_rank: Super Contributor
timestamp: October 08, 2022, 07:41:54 pm
content: Can't really say I have seen many offerings of quartz window eproms in small outline packages? Everyone simply went to single voltage flash memory which are available in SOP.

author: Benta
author_rank: Super Contributor
timestamp: October 08, 2022, 07:50:37 pm
content: The OP wrote "OTP EPROM". No quartz window there.

author: CaptDon
author_rank: Super Contributor
timestamp: October 09, 2022, 03:45:13 am
content: "The replacement IC can be either EPROM (OTP or otherwise)"

author: giosif
author_rank: Frequent Contributor
timestamp: October 11, 2022, 05:53:28 pm
content: Thank you all for the answers!I have found (and ordered) an AT49F1024 from a seller in China.Might turn out to be a dud, but the price was low enough to take the risk.

author: james_s
author_rank: Super Contributor
timestamp: October 11, 2022, 06:24:59 pm
content: There's a very good chance it's counterfeit, but I guess you could get lucky.

author: giosif
author_rank: Frequent Contributor
timestamp: October 12, 2022, 01:38:41 pm
content: You are probably right but, for the money, I thought I might just as well give it a try.
Suitable replacement for ML2430 rechargeable battery - Page 1
Forum section: electronics / beginners

author: giosif
author_rank: Frequent Contributor
timestamp: June 12, 2019, 10:34:00 pm
content: Hi,I am trying to find a replacement for a Sanyo ML2430 rechargeable battery, but with not much luck so far (not at a decent price, anyway).Thing is, the said battery is a Lithium Manganese Dioxide type, while most of the similar batteries I've found are the Lithium Vanadium Pentoxide type.Is it safe to use this latter type instead of the former, considering the circuit it is part of will try to charge the battery?If it's not a good idea to do that, anyone has any suggestions where I could source an ML2430 battery from and at a reasonable price?Thanks!
Suitable Replacement Screens for Displays (second noob post :) ) - Page 1
Forum section: electronics / beginners

author: PerPC
author_rank: Contributor
timestamp: April 28, 2012, 01:36:26 am
content: Ok all yall wizards and wizardesses out there, please if anyone has time wave your magic wand over me and answer me this. ummm, i hear people saying that when looking for a replacement screen for a television its about finding whats suitable. Ok now, here is where im getting at. How the H . E double honkey stick am i suppose to know whats suitable. Is there a suitable tech book or some crap out there that tells me all the parts thats suitable. Is it like a secret book or something like the techanati book of secrets; like in the chapter of suitable displays? Ok let me stop, its just that i am getting answers but half answers. can someone just be direct and could every wizard and wizardess in magic tech DavesLand please unite there powers and help a poor peasant out such as myself(resources do well)

author: vk6zgo
author_rank: Super Contributor
timestamp: April 28, 2012, 04:10:05 am
content: There are plenty of different types of displays out there,even within the major categories"LCD ,Plasma,or even good old Cathode Ray tube (CRT)!What kind of TV,old,new, brandname,model number,year of manufacture?If it is an analog CRT TV,I'd say."Don't bother",as the chance of finding a replacement tube is small,& for a noob,fitting & setting a new tube up is a nightmare.The news isn't a lot better for LCD or Plasma,unfortunately,as again,fitting & setting them up,is very messy.

author: amyk
author_rank: Super Contributor
timestamp: April 28, 2012, 10:45:36 am
content: For plasmas and LCDs you should Google the part number.This is usually more successful for smaller panels like the ones found in laptops.

author: PerPC
author_rank: Contributor
timestamp: April 28, 2012, 04:13:00 pm
content: Sheesh. U know i really have to figure out how the local techs manage to facilitate lcd display screens for their customers. Got one here in cleveland who promotes himself as having "screens for all sizes and types" of lcds, leds, etc etc. I wonder who their supplier is? >.< grrrrrrrrr. Either way thanks still

author: G7PSK
author_rank: Super Contributor
timestamp: April 28, 2012, 08:50:17 pm
content: The only magic answer for screen replacements is to take the serial number of the device and use it to look for the replacement part number of the screen on the devices manufacturers web site, there is one catch I have come across some manufacturers will only allow authorized dealers and repair agents on that part of their site and also will only supply such authorized agency's. Siemens is one such company and so are many others. Another spanner I have come across in the past is the replacement part numbers are totally different from the original this ploy is very popular among car manufacturers, even changing the part numbers from time to time such that even the dealers have trouble finding the right part.
Suitable RIFA replacement - Page 1
Forum section: electronics / beginners

author: giosif
author_rank: Frequent Contributor
timestamp: April 04, 2021, 06:13:10 pm
content: Hi,I am looking for a suitable replacement for a blown 10nF RIFA capacitor (model PME 265 MB 510).It is (used as) an X1 filtering cap in a Tektronix 2215 scope I am trying to repair.My first option would be the Kemet R413I210050T0K (datasheet here:https://docs.rs-online.com/906c/A700000006618006.pdf).Do you see any issues with this replacement?I would also consider other physical formats for the cap (i.e. disc-shaped), as long as they do not exceed 10 mm in diameter since, when installed, the cap is sitting right under the mains filter module and there is not much room in there.Thanks!

author: Benta
author_rank: Super Contributor
timestamp: April 04, 2021, 06:27:56 pm
content: Lots of possibilities: EPCOS, TDK, Kemet... whatever fits.

author: drussell
author_rank: Super Contributor
timestamp: April 04, 2021, 06:57:28 pm
content: There are plenty of potential options to choose from...For example, here are a few X1 ratedfilmandceramicsafety capacitors at Digikey.(You can, of course change the.cato.co.ukor whatever to surf in your local currency.)

author: giosif
author_rank: Frequent Contributor
timestamp: April 04, 2021, 06:59:24 pm
content: Ok. Thank you both!
Suitable varistor / MOV for 230V AC power supply? - Page 1
Forum section: electronics / beginners

author: [Chrille]
author_rank: Contributor
timestamp: March 03, 2024, 09:22:29 pm
content: Hi,I am in the process of designing a DIY power supply that is running on a 230V AC. I would like to add a varistor to the circuit as a safety feature for surge protection, but I am not sure what the specs should be. 230V RMS should equal ~325V peak voltage. Should I select a varistor that is rated slightly higher that the peak voltage like 350V or would a 230V, 250V, 275V or 300V varistor work? How do I know which is the best for my application? What should he energy spec (J) be?Thanks!

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: March 03, 2024, 10:35:21 pm
content: Seehttps://incompliancemag.com/new-requirements-for-movs-used-for-surge-suppression-on-ac-mains-ports/SJ

author: 5U4GB
author_rank: Super Contributor
timestamp: March 04, 2024, 03:07:24 am
content: Quote from: Solder_Junkie on March 03, 2024, 10:35:21 pmWhich contains one of my pet peeves, "an MOV". "An metal oxide varistor"? Where'swhen you need him?Ah, sorry,wrong thread.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 04, 2024, 08:24:08 am
content: Its advisable to choose a MOV 20% above your maximum mains voltage.See alsowww.littelfuse.com/~/media/electronics_technical/application_notes/varistors/littelfuse_selecting_a_littelfuse_varistor_application_note.pdf
Summing Mixer  - Page 1
Forum section: electronics / beginners

author: Jbliss
author_rank: Regular Contributor
timestamp: May 31, 2016, 05:20:59 am
content: Hi allmight be a silly question but what is the point of say 10 k restores is a summing circuit like this is it to match impedanceThanksEg.http://oi52.tinypic.com/21dqvqc.jpg

author: danadak
author_rank: Super Contributor
timestamp: May 31, 2016, 10:01:54 am
content: Spam post ?

author: Jbliss
author_rank: Regular Contributor
timestamp: May 31, 2016, 10:22:26 am
content: ....

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 01, 2016, 03:40:58 am
content: Can't see shit on the tinypic site. Looks like spam to me.

author: Jbliss
author_rank: Regular Contributor
timestamp: June 01, 2016, 09:57:42 am
content: Sorry Guys that Url is not working let me post a Picturesorry

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 01, 2016, 10:36:41 am
content: If you connected all the channels together without resistors, they would cross-talk into each other. Especially left to right (which the 14.3k resistors connect between). The resistors isolate the channels, but at the expense of reducing gain by the same amount.Tim
Summing up piezo voltages - Page 1
Forum section: electronics / beginners

author: SunboX
author_rank: Newbie
timestamp: August 27, 2022, 07:17:09 am
content: Hello,I have three piezo pickups. I'd like to sum the voltages of the three, but I don't have an external voltage source. Only the voltage generated by the piezo.Example (Px == Piezo x):P1 30V + P2 0V + P3 0V = 30VP1 10V + P2 10V + P3 0V = 20VP1 5V + P2 5V + P3 15V = 25VIs something like this feasible? If so, how?VG and thanks, André

author: Psi
author_rank: Super Contributor
timestamp: August 27, 2022, 07:38:44 am
content: Why can't you just wire them all up in series?Note that the timing and polarity of the mechanical impact will have to be identical between all 3 for them to sum correctly.

author: SunboX
author_rank: Newbie
timestamp: August 27, 2022, 11:06:02 am
content: Does this really work? 🤔 Ok, worth a try, but I thought you can't wire them in series.

author: Psi
author_rank: Super Contributor
timestamp: August 27, 2022, 11:49:31 am
content: Are they raw piezo disc elements or something else?The problem i see is getting the impacts to generate exactly the same phased waveforms on all 3 piezosSince they output AC they need to be in sync with each other.but YMMV, i don't really know anything about how guitar pickups work.

author: Manul
author_rank: Super Contributor
timestamp: August 27, 2022, 12:19:23 pm
content: The question is, do you really want to SUM voltages, or you just want to mix them into one channel?There is a slight difference, because summing in series will make a high impedance pickup even higher impedance. You might start loosing low frequencies. Voltage levels from these pickups are already quite high and I don't see a reason to specifically target summing them.And if you mean mixing them, then I would intuitively think more about paralleling pickups. Or three channel preamp and then mix.But I'm no pickup expert.

author: Terry Bites
author_rank: Super Contributor
timestamp: August 31, 2022, 05:32:44 pm
content: You can get the proportional sum or average with just resistors. You need to compensate for the attenuation.Use Millman’s Theorem to verify this result.
Super basic N MOSFET logic level shifter - done correctly? - Page 1
Forum section: electronics / beginners

author: FlashEF
author_rank: Contributor
timestamp: August 25, 2012, 06:28:57 pm
content: Hi. Could anyone tell me if the fallowing circuit is going to work?It is supposed to do a non-inverted conversion from 1.8 V logic to 3,3V. It is surprisingly hard to find information regarding those sort of circuits as they are super basic and simple. I ended up scratching my head and wondering am I right or not.

author: AndyC_772
author_rank: Super Contributor
timestamp: August 25, 2012, 07:02:13 pm
content: I'm afraid not. If you apply 1.8V to the gate, and the Vgs threshold is 0.5V, then the output voltage will be about 1.3V.There's no completely trivial solution that I'm aware of. An inverting level shifter is easier - it's more or less the circuit you've drawn, just turned upside down. Two inverters in series makes for a non-inverting circuit.

author: FlashEF
author_rank: Contributor
timestamp: August 25, 2012, 07:28:51 pm
content: Doesn't the Vgs treshold mean the point where the MOSFET starts to turn on? The ON resistance for this model is roughly in 200 mOhm so shouldn't it be a voltage divider with one resistor of 10k and the other 200mOhm? What am I missing here?

author: SeanB
author_rank: Super Contributor
timestamp: August 25, 2012, 07:34:29 pm
content: 0.5V with respect to the substrate/source. In this case the source will be at the top end of the 10k resistor. You have made a very nice voltage follower. To make a level shifter you will need to make this an inverter by swapping the mosfet and resistor and add another after to invert again. If you need to do this more than once on a board use a proper level translator.

author: fmaimon
author_rank: Unknown
timestamp: August 25, 2012, 08:08:01 pm
content: Check out this application note. Page 10 is what you are looking for.http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf

author: FlashEF
author_rank: Contributor
timestamp: August 25, 2012, 08:32:29 pm
content: Thanks for the datasheet and all other help. The method mentioned on the 10-th page seems easy to implement but I'll probably test it first cause it seems somewhat dependent on the MOSFET model.

author: AndyC_772
author_rank: Super Contributor
timestamp: August 25, 2012, 09:08:20 pm
content: Quote from: FlashEF on August 25, 2012, 07:28:51 pmI'm sure you've got it by now anyway, but: Vgs is the voltage between the gate of the transistor and the source of the transistor. Think carefully about what these two terminals are connected to; if the source were connected to ground, then it would indeed turn fully on with a 1.8V input. But it isn't!

author: FlashEF
author_rank: Contributor
timestamp: August 26, 2012, 02:08:03 pm
content: Thanks AndyC. I taught of the first split second when the bottom of the transistor is pulled to ground, but yes - after the voltage raises the MOS will start to close and settles on it's treshold voltage. Something to keep in mind for the future.
Super capacitor selection and Charging & discharging - Page 1
Forum section: electronics / beginners

author: vignesh_shan
author_rank: Contributor
timestamp: June 30, 2022, 01:30:50 pm
content: Hi enthusiasts,I just need a super capacitor for one of battery operated application, the super cap will be a back up power supply for the design. But i didn't use super cap before,. I need answer for below queries,1) why most of super capacitors are available in 2.3V to 2.7V range ?2) how to charge a super capacitor? Can we apply some minimal voltage at discharged condition and increase the voltage? Is there any plot or explanation about charging?3) please confirm below calculation is correct ?I= 200mA, V= 2.8v to 2.5V need to be discharged at t = 30sC = I * dt/dv= 0.2 * 30/0.3=20FSo required C is 20F ??Please answer the queriesThanks,Vicky
Super high quality "Haicco" FG-100 - Which direction does temperature sensor go? - Page 1
Forum section: electronics / beginners

author: sofakng
author_rank: Regular Contributor
timestamp: February 18, 2022, 08:23:36 pm
content: Hey guys ... I'm excited that I bought a really high quality "Haicco" FG-100 soldering temperature sensor, but lucky for me it also came with very high quality temperature sensors:Only the blue side of the sensor is marked, so which side goes to the red on the FG-100?

author: ledtester
author_rank: Super Contributor
timestamp: February 19, 2022, 07:19:10 am
content: The part no. of the official Hakko part is "191-212":https://hakkousa.com/191-212-replacement-sensor-for-fg-100b-100-101-tip-themometer.htmlBased on the orientation of the center clamp I would hazard to guess that the left loop is the red terminal - but that's just my best guess.You can find the knockoffs on ebay -- just search for "Hakko 191-212".
"Super" Powerful IR Remote, need ideas. - Page 1
Forum section: electronics / beginners

author: Undweeber
author_rank: Regular Contributor
timestamp: September 23, 2019, 12:02:33 am
content: 1. Starting with LED, I would like to use either a 50W or a 100W 940nm LED, the immediate issue, how would I be able to control the pulsing at such high power, I have searched a lot and could not find a project to replicate and steal ideas from to get me started somewhere, so here I am.2. I think I will use some type of Arduino to control it with a phone interface, I am not very imaginative.3. Goal is to be able to turn on and off multiple IR Arduino receivers at once at a distance, there cannot be radio signals used, thus IR, its just as easy and simple, just not sure what to do about the 50-100W power and how to control something that powerful, any ideas?

author: wilfred
author_rank: Super Contributor
timestamp: September 23, 2019, 12:36:49 am
content: What distance? Are all the receivers at the same distance. Could you relay signals from one Arduino device to others? Can you do anything to improve receiver sensitivity through optical means? Shield from sunlight, small dish or lens to collect and focus light. Are the receivers fixed or mobile?Can you even be sure 50W or 100W is sufficient?I would look into IR photoelectric beam sensors and or projects. They can get 100m without very high power diodes.

author: ledtester
author_rank: Super Contributor
timestamp: September 23, 2019, 12:44:10 am
content: What kind of distance?How about using a laser pointer or multiple laser pointers? A 5 milliwatt laser pointer can transmit over hundreds of feet. An unfocused light source will waste most of its input energy.

author: edavid
author_rank: Super Contributor
timestamp: September 23, 2019, 12:58:34 am
content: Quote from: Undweeber on September 23, 2019, 12:02:33 amThis would not be eye safe.

author: soldar
author_rank: Super Contributor
timestamp: September 26, 2019, 06:17:37 pm
content: I used to work for an outfit who installed simultaneous translation equipment in large venues like conferences. The speaker's voice was translated by several people in a booth and then broadcast over several channels on IR carrier. People would have headphones which could select a channel and language.I do not know how many IR diodes were in each panel but well could be a couple hundred or more.The signal input was coax and several panels could be daisy-chained. There was a switch to choose between higher power and lower power.A few panels would cover a large venue like a large auditorium.
Super Regen for AM - Page 1
Forum section: electronics / beginners

author: Simon123
author_rank: Regular Contributor
timestamp: October 27, 2014, 10:46:42 pm
content: Howdy!I'l build this FM receiver:http://www.seekic.com/uploadfile/ic-circuit/s20116225058383.jpg(waiting for sockets)Its a simple super regen circuit which uses slope detection to turn FM into AM.Would it be possible to recieve Shortwave AM- like 6MHz and up to 7.3MHz.I would ofcourse change the LC circuit.Thanks in advance!
super star! - Page 1
Forum section: electronics / beginners

author: steve750
author_rank: Newbie
timestamp: July 01, 2014, 09:53:14 pm
content: Is Dave loosing the plot? I'm an old fart so the trendy bit just passes by.

author: miguelvp
author_rank: Super Contributor
timestamp: July 02, 2014, 12:24:40 am
content: I'm an old fart too but I did like it

author: Dinsdale
author_rank: Regular Contributor
timestamp: July 02, 2014, 01:29:28 pm
content: Old fart here, too.I think E-Loc is pretty talented. Clever writer and re-mixer. Getting Dave's voice to "fit in" was amazing.This will come in handy when you start adding Ben Heckish production values to your vids, Dave.
Supercapacitors anyone ? - Page 1
Forum section: electronics / beginners

author: pootler
author_rank: Newbie
timestamp: March 29, 2021, 07:31:54 pm
content: HI - new here.I am trying to use two ( button ) supercapacitors to provide short term ( about 7 secs ) power to usb peripherals in my car so as to prevent them from dying when the car is cranked.I am using two 4 Farad 5.5 V supercapacitors in parallel, and these are connected across the input to a usb3 hub being fed from a 12V to 5V / 3A voltage adapter.I tried to find some info about what I would require to provide 15W for approx 7/8 secs, and I think this should be enough.So - I am thinking in the right direction here?When the car is cranked, it disconnects all power to accessory feeds which is running the usb hub.When the power goes, the caps if charged, should have enough to ''bridge'' the power gap, until power appears again when the engine starts?However, when power is restored, will the caps not suddenly start draining as much current as possible from the adapter in order to recharge ( i.e. the full 3A ) which will remove power from the usb hub and create another problem?Do I need some kind of resistor before the caps to reduce current claim?Sorry for the language - noob :-)pootler

author: Manul
author_rank: Super Contributor
timestamp: March 29, 2021, 09:13:14 pm
content: I would say it is probably better to put capacitors on the 12V side, input of regulator. That way it would still provide regulated 5V while the cap is discharging. But you still need some sort of inrush limitting.Huge capacitors on the 5V rail would be harder to limit the inrush, might cause instability of converter, would not hold exactly 5V (voltage would drop) and also most converters will alow current to go backwards from output to input if input disappears, so your capacitors might quickly drain into 12V rail, if it is cut off, but has some load on it. That is my thoughts.

author: pootler
author_rank: Newbie
timestamp: March 29, 2021, 09:51:10 pm
content: Thanks manul,I guess I would need another 5.5V cap for that, and then wire in series.Hopefully no need for balancing with only three caps.''Huge'' in capacity - but only an inch in diameter:)Cheerspootler

author: Manul
author_rank: Super Contributor
timestamp: March 29, 2021, 09:57:46 pm
content: Quote from: pootler on March 29, 2021, 09:51:10 pmHmm... not so sure about this, especially if the charge / discharge currents are somewhat high.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 30, 2021, 04:24:36 pm
content: QuoteActually the starter basically shorts out the rest of the car. A 100 A draw on 12 V means there is almost no resistance.Make sure you protect whatever you do from being "sucked up" by the starter....diode between your caps and the car.You will also need to protect the nasty transients caused by the starter turning off.I'm fairly sure TI tells you the answer here:https://www.ti.com/lit/pdf/snva681Don't have time to read it now.
Superconductor Technologies Cryocooler - Help Needed - Page 1
Forum section: electronics / beginners

author: ChildofPhoton
author_rank: Newbie
timestamp: July 13, 2022, 03:36:25 pm
content: Hello everyone, I am new to this forum but am hoping that I can find some assistance with a challenge I am facing.I recently purchased a SuperLink RX unit made by Superconductor Technologies. Originally it was used to enhance certain RF signals I think. Feel free to look it up in this AMAZING post:https://xdevs.com/article/sti/My challenge is that I want to use the actual cooler part of the unit to generate LN2 but the temperature probe used to monitor the actual cold finger temperature was part of the Dewar that encapsulated the super conductor. I am wondering if anyone has any suggestions on how/what can be used instead and also be read by the software that is used to control the unit. Right now I am having to manually increase the W very slowly as to not harm the unit but I can tell from the program (when the unit is whole and has feedback from the Dewar temp probe it can self regulate) that with a temp input it will be able to do this by itself and also self regulate a desired temperature.Please see the attached pictures (taken from the link I included) - any advice would be greatly appreciated.Update: One of the wire pairs seen in the "bottom_of_dewar" image is the connection to the temp probe. I think the actual probe can be seen in the last image and is soldered/glued to the housing?

author: ejeffrey
author_rank: Super Contributor
timestamp: July 13, 2022, 05:18:16 pm
content: I'm not sure what you are after? A temperature sensor that works around 77k? The higher grades of platinum RTDs will work there and has the advantage of being usable uncalibrated, but the most common option is a silicon diode Vf measured at constant current (10 uA is common). This really should be calibrated but you can do a 1 point calibration by dunking in LN2 that will be good enough.If you are trying to condense LN2 from air I highly recommend against that. You will condense oxygen at the same time. Because of the higher boiling point of oxygen the nitrogen will preferentially boil off leaving high concentration of liquid oxygen which is extremely dangerous even in small quantities. Commercial nitrogen liquefaction plants then undergo fractional distillation to separate the oxygen from nitrogen.

author: ChildofPhoton
author_rank: Newbie
timestamp: July 13, 2022, 05:24:55 pm
content: Thanks for the reply, I am simply looking for a way to measure the temperature and have that value be read but the Java application that controls the unit. My fear was that I would have to some how mimic the resistance of the probe originally used so the readings would be correct. As for liquifying air - I have a N2 filter that will remove the other gases present in the atmosphere. It sounds like I need to look into the platinum RTDs - just hope the input is recognized.Could you possibly go into further explanation of what they are and what signal they send to produce measurements?
Spperflat alkaline cell. - Page 1
Forum section: electronics / beginners

author: hamster_nz
author_rank: Super Contributor
timestamp: November 27, 2017, 09:02:52 am
content: I had a project outdoors running on 3 x AA batteries, and noticed that it hadn't checked in on the WiFi for a while. The batteries were flat (due to corrosion on the sensor at first guess). Drat - it was supposed to last all summer.But what was interesting was the three AA batteries. One metered 1.1V, the next 0.9V and the last was -1.0V (yes + was -1.0V relative to the - end).I didn't realize you could discharge a 1.5V cell so low that it would hold -1.0V charge! After shorting for a few seconds it was still reading -0.375V, slowly getting more negative as the cell recovered.Very odd - after about 30 minutes it is now down to -0.25V. I might leave it to the morning and see what happens....

author: ogden
author_rank: Super Contributor
timestamp: November 27, 2017, 09:17:46 am
content: Quote from: hamster_nz on November 27, 2017, 09:02:52 amIt's called battery reversal. Nothing unusual.https://en.wikipedia.org/wiki/Rechargeable_battery#Damage_from_cell_reversalThat's why you always shall use identical batteries in pack - fresh, branded, from same batch/package. For instance when I use NIMH in my photoflash, I sort them by capacity and ESR so there is no "weak link" in battery pack and they all discharge evenly.

author: hamster_nz
author_rank: Super Contributor
timestamp: November 27, 2017, 09:28:11 am
content: Quote from: ogden on November 27, 2017, 09:17:46 amIt seems it was unusual enough that somebody gave it a name, and a couple of paragraphs on a Wikipedia page....I was just surprised at the magnitude of the Voltage, and that it was relatively stable until I shorted it out.

author: ogden
author_rank: Super Contributor
timestamp: November 27, 2017, 09:58:29 am
content: Quote from: hamster_nz on November 27, 2017, 09:28:11 amVoltage alone does not tell much about magnitude of the reversal. Stored energy, capacity (mAh) does. I bet that it was so tiny that it is not even worth electronic ink of internet we are using to talk about it
Superposition theorem - Page 1
Forum section: electronics / beginners

author: JOJOElectro29
author_rank: Contributor
timestamp: May 19, 2025, 12:50:17 am
content: Hi can someone check what I did wrong here?

author: ledtester
author_rank: Super Contributor
timestamp: May 19, 2025, 01:22:26 am
content: For the second case (setting the voltage source to 0) note that the 8-2*j, 4j and 6 impedances are all in parallel. Then you can determine the voltage at the intersection point and thus the current.

author: JOJOElectro29
author_rank: Contributor
timestamp: May 19, 2025, 01:26:09 am
content: For case 2 I wanted to use mesh analysis to find I1 is my KVL equations correct? because my final answer for I0 is wrong

author: ledtester
author_rank: Super Contributor
timestamp: May 19, 2025, 02:05:06 am
content: In the first case you have:$$I_0 = \frac{6}{6+Z} \times \frac{V}{6+Z}$$where \$V = 50 \angle 30 \$, but what you really want to compute is:$$I_0 = \frac{Z}{6+Z}\times V \times \frac{1}{8-2I}$$The voltage at the junction is:$$\frac{Z}{6+Z}\times V$$and then you divide that by \$8-2I\$ to get the current through the desired branch.

author: JOJOElectro29
author_rank: Contributor
timestamp: May 19, 2025, 04:58:28 am
content: Like this?, answer is still wrong.

author: ledtester
author_rank: Super Contributor
timestamp: May 20, 2025, 12:20:17 am
content: Here is some python code which computes the solution:https://www.programiz.com/online-compiler/7ODW5usI7KORNJust hit "Run" to see the output:Code:i0:= 0.39846678890044596 + j* 2.7798668222369307= 2.808279781508652 ∠ 81.84277341263095 degreesi1:= 2.0820189274447958 + j* 2.649842271293376= 3.369935737810384 ∠ 51.84277341263093 degreesi0+i1:= 2.4804857163452416 + j* 5.429709093530306= 5.969468169724877 ∠ 65.44738046442407 degreesFull code here:Code:from math import cos, sin, pi, atan2, sqrtdef par(a,b):return a*b/(a+b)def vdiv(top,bottom):return bottom/(top+bottom)def cis(degs):rads = degs*pi/180return cos(rads)+sin(rads)*1jdef to_polar(z):theta = atan2(z.imag, z.real)*180/pir = sqrt( z.imag*z.imag + z.real*z.real)return (r, theta)def show_complex(title, z):r, theta = to_polar(z)print(title+":")print(" =", z.real, "+", "j*", z.imag)print(" =", r, "∠", theta, "degrees")def solve():zlower = par(8-2j, 4j)v = 50*cis(30)*vdiv(6, zlower)i0 = v/(8-2j)show_complex("i0", i0)zpar = par(8-2j, par(4j, 6))v2 = 10*zpari1 = v2/(8-2j)show_complex("i1", i1)show_complex("i0+i1", i0+i1)solve()

author: ledtester
author_rank: Super Contributor
timestamp: May 20, 2025, 06:14:11 am
content: The problem is when you compute the discriminate of the second set of equations...It should be 56 + 44j.The real term is 48 - 8 - (-4j)*(-4j) = 48 - 8 + 16 = 56.All of those minus signs can get confusing!

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 20, 2025, 10:09:43 am
content: It's been a long time since I did this. My biggest problem was with being consequent in the direction of the arrows. For example in your c11c8e8209074c8e8630f40eb46ca3f picture I1 and I1 have opposite directions though the J4 Ohm Inductor.
Supply-cap ESR - Page 1
Forum section: electronics / beginners

author: wiss
author_rank: Frequent Contributor
timestamp: April 29, 2014, 09:27:38 pm
content: In an old style linear power-supply:Will increased ESR in supply-caps increase the total power consumed by a device?Assuming that the (regulated) current required does not increase, think rectified to 10 V and feed through a 7805 for example.I could probably spend some time calculating this but it's probably faster and more accurate to ask her

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 29, 2014, 09:56:00 pm
content: A little, due to increased ripple. The minimum peak voltage (dropout) also drops, which eventually leads to ripple passing through the regulator. Not to mention capacitance usually falls at the same time ESR rises, making things that much worse.I think there's a small amount of runaway, in that, as a cap dries out, its ESR rises, making it hotter, making it dry out faster...Tim

author: wiss
author_rank: Frequent Contributor
timestamp: April 29, 2014, 10:22:09 pm
content: Mmm, pretty much what I guessed, ofcourse the cap will run hotter and the regulator cooler but no major total change...

author: lewis
author_rank: Frequent Contributor
timestamp: April 29, 2014, 11:44:40 pm
content: Quote from: T3sl4co1l on April 29, 2014, 09:56:00 pmIncreased ripple actuallyreducespower dissipation in a linear regulator because the RMS voltage across the regulator is lower. This might compensate for any power loss in the capacitor due to its increased ESR, someone better at maths than me will be able to tell you!

author: wiss
author_rank: Frequent Contributor
timestamp: April 30, 2014, 05:41:56 am
content: But then the charging-pulses will be larger generating more heat in the transformer. But how much?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 30, 2014, 07:25:45 am
content: Quote from: wiss on April 29, 2014, 10:22:09 pmNo, I think total will go up slightly. The peaks are much higher, and the valleys lower; the transformer's RMS current is higher than the DC load current, so there's more loss there. (The RMS/DC ratio will be lower, but always above 1, unless active PFC is used.)Total dissipation may drop if capacitance rises, causing ripple to rise even further and making dropout a bigger issue.Tim