hybridfree/eevblog-posts huggingface dataset:
Removing Solder Resist - Page 1
Forum section: electronics / projects

author: itdontgo
author_rank: Regular Contributor
timestamp: February 27, 2015, 12:17:54 pm
content: Hi,Does anybody know of a chemical which can remove solder resist from a PCB completely. I could obviously rub it off with sandpaper but I need to preserve the laminate and not scratch it. I tried brake fluid given what it does to car paint! Didn't work

author: nanofrog
author_rank: Super Contributor
timestamp: February 27, 2015, 07:10:21 pm
content: TheWhat common chemicals can remove soldermask?thread might be of interest.Seems things aren't as easy to come by in Europe these days (environmental/health & safety regs), but it may still offer up some ideas (especially if you've some of this chemistry sitting around).

author: itdontgo
author_rank: Regular Contributor
timestamp: March 02, 2015, 04:31:27 pm
content: Thanks!

author: kurt
author_rank: Contributor
timestamp: March 02, 2015, 09:57:26 pm
content: If I screw up when applying solder mask to my DIY PCBs I strip it with Sodium Hydroxide (NaOH) before starting over. I mix it much stronger than the 1.5% mixture I use for stripping photoresist, but I don't have an exact ratio. I just add a lot to water, and if it don't act as fast as I want it to I add moreThere is probably different types of solder mask compounds out there and I don't know if it works for all. But the stuff I apply to my boards seems resistant to just about anything else (like acetone) but strips when soaked in NaOH. And so will your skin, so be careful

author: Anks
author_rank: Frequent Contributor
timestamp: March 02, 2015, 11:51:01 pm
content: Quote from: kurt on March 02, 2015, 09:57:26 pmexactly the same as the way I do it.

author: itdontgo
author_rank: Regular Contributor
timestamp: March 03, 2015, 01:07:59 pm
content: I don't know why I didn't think of trying the photoresist stuff. I'll give it a go.I wonder if I can dissolve my finger prints off whilst I'm at it. They'll never catch me!

author: BradC
author_rank: Super Contributor
timestamp: March 03, 2015, 01:40:26 pm
content: Quote from: itdontgo on March 03, 2015, 01:07:59 pmI know you're not serious, but :A) It really, really, really hurtsB) they grow back *exactly* the same minus any damage caused by lasting scar tissue.
Removing tarnish from high voltage high vacuum feedthrough - Page 1
Forum section: electronics / projects

author: ChristofferB
author_rank: Frequent Contributor
timestamp: March 03, 2021, 08:30:06 pm
content: Hi!I've just received this really nice NOS MDC vacuum feedthrough. It's a hollow 1/4" copper tube insulated through the vacuum flange by about 18mm of ceramic insulator.I guess its hollow for high powered applications where the electrodes themselves has cooling water running in them. I'm unsure. I'm gonna seal it with a blob of Sn/Ag solder.Either way, how would one go about removing the copper tarnish? Abrasives are bad, as fine particles are difficult to get rid of.Maybe dilute hydrochloric acid or 30% acetic acid?I'm worried about galvanic corrosion, and deterioration of the metal/ceramic seal...Also, could anyone venture a guess on the max operating voltage?Thanks in advance!

author: Tomorokoshi
author_rank: Super Contributor
timestamp: March 03, 2021, 09:05:53 pm
content: That's tricky because of the special conditions. Perhaps one of the Deoxit series:https://caig.com/

author: ChristofferB
author_rank: Frequent Contributor
timestamp: March 03, 2021, 09:28:16 pm
content: That could be, I will look for an equivalent brand in the EU. Thanks!Either way I will try not to expose the ceramic. The inside of the tube could be cleaned by just pushing liquid through a hose attached on each end, and the outside ends with a rag.

author: vindoline
author_rank: Unknown
timestamp: March 04, 2021, 12:11:09 am
content: Chris, it's not clear to me why you want to clean the copper. However, since you're a chemist, you can brush on a solution of sodium chloride and citric acid. That will strip the oxide off the copper. I don’t imagine it will effect the copper/ceramic junction.
Removing the load from a triac circuit - Page 1
Forum section: electronics / projects

author: that_guy
author_rank: Contributor
timestamp: September 27, 2017, 08:02:25 am
content: Hi,I have a triac doing phase-angle control of a 240V heating element. The element is connected between MT2 and neutral. I'd like to add a simple SPST switch between MT2 and the load to allow the load to be temporarily disconnected and re-inserted without changing the phase angle controller.Will the triac be damaged by the sudden removal and reinsertion of the load while phase-angle control is happening?

author: oldway
author_rank: Super Contributor
timestamp: September 27, 2017, 11:37:28 am
content: No, no risk at all.....
Removing Tuner from Denon dra-335r - Page 1
Forum section: electronics / projects

author: cybernaux
author_rank: Newbie
timestamp: February 10, 2012, 01:00:48 pm
content: Hello,would you show me how to disconnect the tuner part of this amp? From all I know, an amp without tuner will have much less noise distortion.Here are the schematics of the DRA-435 which is almost the same as the 335r:http://www.eserviceinfo.com/download.php?fileid=31997Many thanks for the help,Antonio DiasCheers

author: amspire
author_rank: Super Contributor
timestamp: February 10, 2012, 01:11:49 pm
content: I doubt that the tuner can have any effect on distortion. I would be surprised if it affected noise - it should not.If you can hear noise when using the CD or tape input an the volume set for a reasonable listening level, then it sounds like something is wrong.

author: cybernaux
author_rank: Newbie
timestamp: February 10, 2012, 01:20:38 pm
content: The amp is working fine, no hum or anything. But there's always some electronic noise going on inside de circuit board, as far as I knowThats the reason why high end systems are build alone (modules).When the amps is on, even playing the mode CD, the screen is always on saying the frequency of FM or AM.Many thanks,Dias

author: Fraser
author_rank: Super Contributor
timestamp: February 11, 2012, 11:49:36 am
content: Sounds more like noise associated with the display circuit than the tuner itself. This is not uncommon as it uses a tube display and there are quite high voltages involved. You just need to disable the display driver electronics but can you still operate the unit without a display ?Its worth checking the audio forums to see if this is a known problem first. You could just be suffering from failing decoupling and smoothing capacitors.Aurora

author: Unknown
author_rank: Unknown
timestamp: February 11, 2012, 01:49:19 pm
content: So you can't hear or measure the problem, but you just assume it's there. How would you check if the change had any positive effect?
Removing voltage spikes in a Phototransistor circuit - Page 1
Forum section: electronics / projects

author: girishji
author_rank: Contributor
timestamp: September 23, 2023, 06:38:45 am
content: I have a IR LED and PT (phototransistor) setup where LED is switched at moderate frequency. PT is connected to an amplifier circuit to increase response time. There are 5 PT's connected in parallel. There are also 5 IR Led's, one per each PT (not shown).Only one of the 5 LEDs is powered at any given time for 10-15us, followed by the next one and so on. So only one of the 5 PTs is active at a given time. But one of the LED is blocked occasionally to get voltage transition measured across Vout (Vcc is 3.3v). I am using a RP2040 to turn on LEDs through software.Whenever IR LED is blocked, oscilloscope registers sharp spike of 50v or more at the edge of the square signal. In fact, it registers sharp spikes whenver there is a sharp edge.Any idea what is going on here? Any solution how to avoid damage?

author: tggzzz
author_rank: Super Contributor
timestamp: September 23, 2023, 07:05:26 am
content: It is unlikely voltage spikes are related to the phototransistor. It is more likely that it is related to connecting the scope to your circuit, possibly due to where you are connecting the probe shield, possibly due to the PSU in your circuit.I suggest you use a voltmeter to measure voltages between the probe's shield and various parts of your circuit.(Oh, it isn't important yet, but "numbers not adjectives" hence "moderate frequency" => "x Hz"The 15µs helps, of course)
Renegotiation of an established USB-PD contract as source  - Page 1
Forum section: electronics / projects

author: johofz
author_rank: Contributor
timestamp: February 19, 2023, 01:15:46 pm
content: Hello EEVblog community,I'm researching the USB-PD 3.0 spec for a few days now and can not find information on whether it is possible to initiate a renegotiation with different PDOs as source device after the initial contract is established. In my application the capabilities of the source change dynamically and I need to set the current limit accordingly. I could achieve this by temporarily disconnect from the sink, but that is a nasty solution.A quick clarification would be much appreciated.Greetingsjohofz

author: elbucki
author_rank: Newbie
timestamp: February 23, 2023, 03:54:48 am
content: As a source, you should just have to send another source capabilities message with your updated PDOs. The sink will then have to request a new PDO based off what you sent and use the updated current values. Most all of the sinks I’ve encountered can do this without dropping Vbus.

author: johofz
author_rank: Contributor
timestamp: February 24, 2023, 02:08:25 pm
content: Thank you for your reply! Your information is very helpful.I'm planning to try this out using an evaluation board from ST once I receive it. I'll confirm if the sink device can handle the updated PDOs without dropping Vbus.
Renesas ISL3173 at 5V VCC? - Page 1
Forum section: electronics / projects

author: peter-h
author_rank: Super Contributor
timestamp: October 06, 2021, 02:08:27 pm
content: It says everywhere it is a 3.3V devicehttps://www.renesas.com/us/en/document/dst/isl3170e-isl3171e-isl3172e-isl3173e-isl3174e-isl3175e-isl3176e-isl3177e-isl3178ebut the absolute max is 7VIs there something I am missing, or is this just marketing aiming this device at the 3.3V market?
Repackaged vehicle fuses being sold on Amazon - Page 1
Forum section: electronics / projects

author: calzap
author_rank: Frequent Contributor
timestamp: March 06, 2024, 10:02:35 pm
content: I recently went through my vehicle fuse collection and weeded-out off-brand and no-brand fuses. To replace the tossed fuses, I ordered from a couple of sellers, one of which was Amazon. The most common reputable brands in the U.S. are Bussmann and Littelfuse. Some of the supposedly Bussman fuses from Amazon appeared genuine. These were packaged in blister packs with characteristic Bussmann designs on the cardboard backing. And BUSS or BUSSMANN inscriptions were molded into the plastic housing of the fuses themselves. I might test a couple.However, there were some FLF-40 cartridge fuses with suspicious packaging. The packaging was individual poly bags with a simple B&W printed label. On examination of the fuses themselves, the inscription in the plastic was AURORA. And there were some ATC-35 twin blade fuses in realistic looking Bussmann sliding cases … the common kind with a little plastic drawer that slides out of a metal housing. However, the printing on the case did not match the pictures in the ad. The inscription on the plastic housing of the fuses was PACIFIC.I talked to a Bussmann rep. He said Bussmann never out-sources, rebadges or repackages fuses. Fuses were returned. I left bad reviews and filed complaints with Amazon. I’m done with Amazon as a source of fuses. Finally, it’s really important to look at inscriptions on fuses themselves which sometimes requires a magnifying glass.Mike

author: inse
author_rank: Super Contributor
timestamp: March 06, 2024, 10:12:56 pm
content: For sure Amazon and eBay are not the places for serious sourcing, neither is Aliexpress.You get what you pay for…
Repair and Retrofit of an older "Power Max" Bench PSU. - Page 1
Forum section: electronics / projects

author: Jebnor
author_rank: Regular Contributor
timestamp: August 31, 2014, 05:57:57 pm
content: I repaired an older "Power Max" brand PSU and decided to add a front panel fuse. The PSU is based on the LM723, an older voltage regulator. I had to replace the power pass transistor as it was blown. I also added a front panel fuse holder.Also, I made a video of it.Constructive criticism please, both technical and production. I'd like to improve my videos in future.

author: void_error
author_rank: Frequent Contributor
timestamp: September 01, 2014, 12:25:04 am
content: If you look at the internal schematic of the 723 you'll notice that the current is sensed using a BE junction, basically a diode as far as temp coefficient is concerned (approx -2mV/C) which means that your current limit value decreases with temperature which is not necessarily a bad thing. It was probably set to 4.8A for that exact reason. Take a look at Figure 8.http://www.ti.com/lit/ds/symlink/lm723.pdf

author: Jebnor
author_rank: Regular Contributor
timestamp: September 01, 2014, 01:04:28 am
content: Quote from: void_error on September 01, 2014, 12:25:04 amI had opened this before and put the two 0R27 in parallel. I can't remember what was in there before, for either the Transistor nor the Rsc resistor. I put the TIP122 in because that is what I had, same for the 0R27.I hadn't thought about the tempco, I'll keep that in mind.

author: SeanB
author_rank: Super Contributor
timestamp: September 01, 2014, 05:46:45 pm
content: You probably will also be best advised to put a 100R resistor in series with the top (pin2) lead of the current limiter, so that you do not blow out the current limit transistor into a short circuit. It will increase the short circuit current slightly, but the 723 was never a stellar performer in current limit any way.You probably want a bigger heatsink on it, the flat plate is too small for a high current output for long periods. I took my clone and added a larger old CPU heatsink to it to get it to run cooler than the 120C it originally was running at.
Repair Manual for .pdf 2002 Camry 86120-AA040 Fujitsu Ten Head  - Page 1
Forum section: electronics / projects

author: ron_ditto
author_rank: Newbie
timestamp: May 10, 2021, 04:46:43 am
content: Hi there. Thanks for letting me join.I'm trying to tap into the CD signal of this head unit to add an AUX and bluetooth. I know that buying an aftermarket unit is a "better" option but I want to leave things looking original in my car.I can tap into the tape line but I'd like to tap into the CD line in (is that better though?).I'm having a lot of trouble finding a repair .pdf for the 86120-AA040 that doesn't require me to buy it that I can use to make sense of the PCB.Does anyone know where I could find such a thing or have any advice about how to proceed? On the left of the board there is a vertical connector which is connected to the LCH and RCH solder points but I don't know what it is for. The horizontal ribbon connector is for the CD.The chip that the tape head reader is touching is a 1200500-124KG1 Fujitsu Ten chip which I think might be the CD controller. Even a device specific pinout would be handy.

author: viperidae
author_rank: Frequent Contributor
timestamp: May 10, 2021, 07:15:04 am
content: You might find the signal from the cd player is digital all the way to the audio switching chip.That was the case when I was reverse engineering my old Honda heading. It was i2s from the cd to the mux. It's cheaper and makes no sense to convert the cd audio into analog, just to convert it back to digital in the audio mux chip to apply the DSP EQ, volume and fader control.

author: samnmax
author_rank: Regular Contributor
timestamp: May 10, 2021, 08:44:23 am
content: I would put the AUX/BT input after the tape preamplifier (probably the chip under the ribbon), see if you can find a datasheet of that chip or identify the audio output traces. You may have to fake with a switch the detection of tape inserted.

author: ron_ditto
author_rank: Newbie
timestamp: May 10, 2021, 12:40:03 pm
content: Absolutely.There are a lot of shady looking sites that claim to have the diagrams and data I require but I don't trust them enough to put in my credit card details.That's what I'm hoping people can help with.

author: ron_ditto
author_rank: Newbie
timestamp: May 10, 2021, 12:41:52 pm
content: Thank you.I'm on the right track then.It's finding that pinout data that's proving to be a challenge.

author: ron_ditto
author_rank: Newbie
timestamp: May 13, 2021, 04:02:33 am
content: In case anyone is following along here, I found a site in Russian that had the information I required. You'll need to Google translate it but it's what I've been searching for for the last few weeks.https://www.drive2.ru/l/572825493057855637/
repair of a Sony SCD XE670 SACD player [Solved] - Page 1
Forum section: electronics / projects

author: Satbeginner
author_rank: Regular Contributor
timestamp: October 18, 2018, 10:05:46 am
content: Hi all,just to document the successful repair of my Sony Super Audio CD player.It had developed a problem reading discs till the point where it would never read a disc at all.Looking on the internet I found it was a typical problem for earlier Sony SACD players, these lasers would just die quite soon.Anyway, long story short: I replaced the laser and now it is up-and-running again.The new laser and transport was a fully compatible drop-in replacement, so replacing it was about an hour work.One thing to pay attention to: The new laser arrived with four contacts soldered together as an ESD protection,.This little blob of solder -next to the connector- needs to be removed before mounting the laser.I bought my laser at this Chinese AliEXpress store during a sale, so I got it perfectly packed safe-and-sound at my home for only € 24,- !!AliExpress store:https://s.click.aliexpress.com/e/c93YTFc5I do not have any link with this seller, just a good experience.Here some pictures.Un saludo,Leo

author: macboy
author_rank: Super Contributor
timestamp: October 19, 2018, 02:28:01 pm
content: Good work.I am jealous of your SACD copy of DSoTM. I had put this and a few other classic rock titles on my gift wish lists for years, and myDWnever took the hint. By the time I gave up and went shopping for them myself, they were out of print and prices were obscene.
Repairing a flickering LED spotlight - Page 1
Forum section: electronics / projects

author: SolderSucker
author_rank: Regular Contributor
timestamp: June 03, 2020, 12:24:48 pm
content: One of the LED spotlights in my kitchen recently started flickering so I thought I'd save myself some money and repair ir. Sure enough, one of the surface mounted LEDs had a black scorch mark through it (there are ten LEDs) so not having any spares of that type I replaced it with a wire jumper.It works fine now, trouble is I had to use my Dremel to carefully remove the opaque dome from the body of the bulb. On studying the white glue used to stick it on place it looks like it may have been standard silicone sealant. Is this likely the case or would some kind of special adhesive been used?If it was silicone sealant I have some so could use that to re-attach the dome, but if not what would be best to use? As the bulb gets pretty warm I'm assuming that hot melt glue isn't a good option. How about epoxy resin?Also out of interest, would there have been a better way to remove the dome instead of using my Dremel? I ask this for possible future reference.

author: phil from seattle
author_rank: Super Contributor
timestamp: June 03, 2020, 01:43:10 pm
content: Hmmm. I bet they are in an unvented fixture - overheating. I'd also bet that your fix won't last long. Best to replace the whole unit.I have a kitchen with lots of MR-16 fixtures and the lamps burn out regularly. No where near the 20,000 hour claims of the manufacturers though better than halogens. I'm using them in a "bell" housing which traps the heat. The wife likes the look of them so we live with replacing a couple every year. Good that they've gotten so cheap.I'd just use some epoxy to glue the dome back.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 03, 2020, 02:29:43 pm
content: Most of the flickering issues you have in led stuff are bad drivers boards, and the second problems is the quality grade of the leds used in appliances, there is many parts quality floating around...I've bought high quality led lamps and they do their life ratings, sure the prices goes with them, and ive bought china made stuff and they dont even do half of their supposed remaining life.
reparing my GoKart Computer after battery shorting the PCB :/ - Page 1
Forum section: electronics / projects

author: phaseform
author_rank: Regular Contributor
timestamp: October 20, 2014, 03:02:19 pm
content: An old battery leaked all through my GoKart timer, which I fixed yesterday. Thought some may find it somewhat interesting.Did a write up here:http://projects.hascomp.net/Pro_Plus/- I haven't replaced LEDs as I'm worried I could damage the circuit more by doing so, ie the LED transistors are shorted high or something.- There are a couple square yellow SMD parts I didn't replace - possibly caps? which were cracked - not sure if this is living dangerously..Cheers
Replace a rechargable button cell with a supercap? In a camera. - Page 1
Forum section: electronics / projects

author: wilfred
author_rank: Super Contributor
timestamp: January 14, 2020, 08:46:08 am
content: I have a digital camera that is getting on but I still like it. It is a Nikon P7000 and the camera has started losing the date and time as well as other settings when I remove the battery to recharge it.I can't find much on this model but similar models seem to use a battery similar to one of these.https://au.mouser.com/Seiko-Instruments/Power/Batteries/Coin-Cell-Battery/_/N-965wk?P=1z0y6z5Z1z0y70eZ1z0zp45Z1y8f1hoI only use the camera occasionally in bursts and I only need the settings saved long enough to charge the battery. A few hours would be great but a day or two would be better.Would a 0.22F 3.3V supercap be a suitable option for both retention time and as a replacement for a battery in a device originally designed to charge a battery?I have some of these caps which is why I am specific. They also should be small enough to fit.Until I open the camera (shudder) I don't know what exact battery it uses. I haven't found a service manual for the P7000 and other manuals for Nikon Coolpix camera don't list the battery replacement or part number.

author: Prehistoricman
author_rank: Regular Contributor
timestamp: January 14, 2020, 09:35:59 am
content: The camera may not use the internal battery to charge the backup battery. Are you sure the one you removed is rechargeable?If it does though, then I see no issues. What's the maximum voltage of the main battery?

author: wilfred
author_rank: Super Contributor
timestamp: January 14, 2020, 11:05:33 am
content: I haven't removed it yet but similar Nikon Coolpix cameras seem to use the rechargable button cells. I am just assuming mine is similar.Looking at the datasheet here for a battery I found referenced in another teardownhttps://www.sii.co.jp/en/me/datasheets/ms-rechargeable/ms414ge/it says a charge/discharge cycle of 50 times for 100% discharge. So it is plausible the battery is dead. I want to avoid a repeat by using a supercap.

author: Mr Evil
author_rank: Regular Contributor
timestamp: January 14, 2020, 05:06:59 pm
content: You'll have to measure the current drawn from the battery, and the minimum voltage that the camera needs, and work out if the supercapacitor can remain above that voltage for long enough at that current. 0.22F won't provide much current for a day though.You'll also want to check that the charging circuit is compatible. If it's a simple 3.3V source connected to the battery through a resistor then it will be fine.
Replace CR2032 battery with 18650 - Page 1
Forum section: electronics / projects

author: tingkeeyong
author_rank: Newbie
timestamp: September 20, 2021, 12:00:19 pm
content: Hi, I am looking to modifyXiaomi thermometerfrom using CR2032 into 18650 lithium ion battery. My major concern is, if 18650 voltage could be too high for the thermometer, especially 18650 can be 4.2V when fully charged. Can anyone advice if it's workable. Thanks.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 20, 2021, 12:12:08 pm
content: Maybe add a 3.3v micropower LDO to be safe?

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 20, 2021, 12:32:53 pm
content: How about use a small LiFePO4 cell?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 20, 2021, 12:59:15 pm
content: Or a pair of alkaline AA's..?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 20, 2021, 01:31:40 pm
content: Or just put a (few) diodes or an LED in series with the LiPo.You do have to make sure the voltage drop is adequate over the whole power range (idle and sampling).Voltage regulators always need a bit of current for themselves, and you have to look good at the specifications to verify the one you use does not need to much. Some go up to several milli amps.LiPo's also need a good cutoff as protection agaist over discharging.LiFePo may also be a good solution, It has a bit lower output voltage, but I think it's also more robust.Yet another option is to use LIR2032. Same size as CR2032, but rechargeable.Edit:I had a click on that amazon link, and according to the description it already uses LiPo.Do you get some commission for page visits on amazon or something like that?

author: Labrat101
author_rank: Unknown
timestamp: September 20, 2021, 05:01:42 pm
content: What's wrong in using a Duracell CR 123a series 3.2 volt, same voltage better specs
Replace DC axial fan's impeller from other same type, but different voltage ? - Page 1
Forum section: electronics / projects

author: BravoV
author_rank: Super Contributor
timestamp: May 02, 2020, 05:48:13 pm
content: As subject says, and both are exact same type/model, its a quality aluminium frame, plastic impeller DC axial fan made by Sanyo Denki.The broken one is rated at 12V, and has one of it's blade gone caused by stupid accident as a screw driver was dropped into the spinning fan.Locally I have a cheap offering of the exact same type and model, but its different voltage variant that is rated at 48V.From the tear down of the current broken one, the plastic impeller has the embedded circle magnet, and thinking (wishfully) whether its possible to fix it by just pulling the impeller from the 48V version, and then install it at the 12V one ?

author: james_s
author_rank: Super Contributor
timestamp: May 02, 2020, 05:50:35 pm
content: It will probably work, the only difference is likely to be the windings on the stator core and possibly the ratings of some components. If it has the same number of blades then the blade assembly is probably identical. Only way to find out for sure is get one and take it apart.
Replace Eprom by Flash. - Page 1
Forum section: electronics / projects

author: luiHS
author_rank: Frequent Contributor
timestamp: April 22, 2020, 07:19:31 pm
content: Hi.Is it possible, in a circuit, to replace an Eprom memory 27C010 by Flash memory SST39SF010A ?The memory chip is not updated once it is burned with the programmer (a Chinese TL866), and in the circuit it is only read.I see that the only different pin is PGM and WE pins, although it seems to me that on both chips its used for the same purpose, to write the content, and in the case of the Flash also to erase it.The Eprom, a 27c010 I only find it in DIP and PLCC32 packages, that's why I prefer to use a Flash that is in TSOP32 package. But I don't know if there is compatibility.Regards.
replace LM324 by TL074CN ? - Page 1
Forum section: electronics / projects

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: May 07, 2016, 06:23:13 pm
content: I am repairing a linear power supply and need to change a LM324 which I have not in stock.I have some TL074CNIs there any obvious problem to replace one by the other ?Are there any other possible for a PDIP replacement of the LM324.Thanks

author: Kleinstein
author_rank: Super Contributor
timestamp: May 07, 2016, 07:48:06 pm
content: It depends on the circuit. The LM324 is single supply and can withstand input voltage higher than the supply.So in some circuits the TL074 / TL084 might work Ok in others it might not, because the TL074 are nor single supply.

author: edavid
author_rank: Super Contributor
timestamp: May 07, 2016, 07:56:07 pm
content: Quote from: JacquesBBB on May 07, 2016, 06:23:13 pmProbably won't work because of different common mode range.QuoteLM2902But why don't you stock the LM324It's the most common op amp in the world.

author: Cerebus
author_rank: Super Contributor
timestamp: May 07, 2016, 08:32:46 pm
content: LT1014 from Linear (and second sourced from Texas) is a direct replacement with much, much better parametrics. The Texas 'D' version can be had for jelly-bean prices and even that is still much, much better than the LM324.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 07, 2016, 08:36:25 pm
content: The LM2902 is the low grade version, with a slightly lower maximum supply voltage than the LM324/LM358.

author: edavid
author_rank: Super Contributor
timestamp: May 07, 2016, 09:14:52 pm
content: Quote from: Kleinstein on May 07, 2016, 08:36:25 pmFor historical reasons, but I doubt they bother having a separate test program for it.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: May 08, 2016, 04:34:07 pm
content: Thanks for all for your advices.Quote from: edavid on May 07, 2016, 07:56:07 pmI understand that now. It is impressive as there is always something essential that is missing. I have ordered a bunch of these today as they are very cheap.Quote from: Cerebus on May 07, 2016, 08:32:46 pmAt Mouser : LM324 0,179 € /100 LT1014 : 3,68 €/100 in PDIP version .Difficult to switch from LM324 to LT1014 if not necessary.But I appreciate the advice, and will try to get a few of those.Finally, I rescued a LM324 from an old board, just to find that his was not the culprit. The problem was indeed in this corner, but mostly coming from the caps that were associated to the LM324. I was misled because of the strange behavior depending on the voltage range.The PSU is now working (nearly ) fine. I have just a remaining high frequency of about 10 mV that I will try to get rid off some day.

author: dannyf
author_rank: Super Contributor
timestamp: May 09, 2016, 10:12:03 pm
content: Lm324, like 358, can take input near gnd.Tl0x4 cannot.
Replace P2111 Memory Bank - Page 1
Forum section: electronics / projects

author: asp
author_rank: Regular Contributor
timestamp: November 16, 2021, 02:49:55 pm
content: HiMaybe somebody has an idea regarding a memory upgrade/change. I have board that uses P2111A-4 SRAM memory (4 of them) and I think one my have gone bad and I would want to replace it, but It's close to impossible to find any so I thought that maybe I can change the memory to something else so I created a board but before I order it and see if it works I wanted to ask anyone if this design should work in theory. Below is the original schematic and my daughter board version that uses W24257AK-15I have removed everything from the schematic that is not part of the memory thing just so it's easier but I can add the full schematic if needed.Any thoughts?EDIT: Nope it won't work! Need to rethink it.
Replace PESD1CAN with two TVS? - Page 1
Forum section: electronics / projects

author: okw
author_rank: Frequent Contributor
timestamp: June 21, 2023, 08:20:14 pm
content: I'm looking to replace an ESD for CANBUS with a more generic product. PESD1CAN is two bidirectional TVS and comes in SOT23, and if possible I would like to replace it with two generic SOD523 or similar (more flexible in tight layout).I'm not sure how to read the PESD1CAN datasheet, and choose a "identical" or better spec'ed TVS.Like "RATED STAND-OFF VOLTAGE", should I choose exactly 24V or is higher also fine? And with the "MINIMUM BREAKDOWN VOLTAGE", can I go lower? And "MAXIMUM CLAMPING VOLTAGE", should I choose the same or higher? Etc.How to choose?

author: Niklas
author_rank: Frequent Contributor
timestamp: June 21, 2023, 08:45:04 pm
content: Low capacitance. 100pF or less for the combination of CAN transceiver, filter and TVS.Bidirectional diode. Important if 0V connection is lost, could otherwise hang the bus.Standoff voltage should be above maximum operating voltage so a harness short or miswiring does not damage the TVS. 24V is OK for passenger cars. Trucks and buses with 24 V battery will need closer to 36V to on the safe side.Clamping voltage should cover the absolute maximum rating of the CAN transceiver and filtering components.Also check the specifications for what ESD voltages and method (machine or human body) it is supposed to handle. Smaller package might not be able to handle the same pulse energy.
Replace PS transformer with Switched supply? - Page 1
Forum section: electronics / projects

author: rodcastler
author_rank: Regular Contributor
timestamp: April 07, 2014, 04:30:29 pm
content: My power supply is kind of heavy, and I happen to have a fine switching Allen Bradley fixed 24V/8A power supply lying around as well.Would it be feasible to replace the heavy AC 30V/5A transformer with the lightweight DC 24V/8A one inside my Korad PS? What are the implications?Note: I assume it's not a direct replacement since for a start one is AC the other one is DC, one is 30V the other one is 24V, and I also haven't checked if the transformer has several taps, and all that. But the thing is that I wouldn't mind to trade weight for having the PS to go only up to 24V.

author: ejeffrey
author_rank: Super Contributor
timestamp: April 08, 2014, 03:55:58 am
content: Adjustable supplies usually have multi-tap transformers so that they don't have to dissipate too much power in the pass transistors at low operating voltage. If you connect a fixed supply it will probably overheat.
replace releys with electronic circuit - Page 1
Forum section: electronics / projects

author: nmugzy40
author_rank: Newbie
timestamp: July 10, 2016, 06:08:51 pm
content: Hi my name is Nick I designed a relay circuit to control a plasma cutter torch straight line cutter. I would realy like to replace it with solid state circuit. I saw a soft latching switch on YouTube recently and it seemed it could work. I need to be able to start a small 24v motor. When the torch reaches the end of the cut its carriage makes contact with a micro switch and shuts the motor off. Another button on the control panel returns the carriage back to the starting position by reversing the motor. Both of these switches are latching the motor on in both directions. I also want to be able to latch the torch on till it reaches the end of the cut. At that point it will contact a micro switch and shut the torch off. The torch on & off is accomplished by putting a short circuit on pin 1 & 2 at the plasma cutter power source. I am hoping someone can help me design the three circuits to control my machine. Thanks

author: uncle_bob
author_rank: Unknown
timestamp: July 10, 2016, 07:47:48 pm
content: HiWhy do you want to replace the circuit you have? What is the objective of the circuit change?You are dealing with stuff that is pretty hostile to solid state devices ....Bob

author: nmugzy40
author_rank: Newbie
timestamp: July 11, 2016, 01:00:22 am
content: Thank you for replying. Relays are large and I'm trying to build a control circuit in a small package. I don't he the relay sockets so I had to solder all the wires to th e pins on the relays. I think it would be a much cleaner build.

author: uncle_bob
author_rank: Unknown
timestamp: July 11, 2016, 01:28:11 am
content: HiDIN Rail was pretty much invented for this sort of thing. Why not just rig the relays on a rail and be done with it?Relays aren't bothered when a few thousand volts drifts around and drops a couple hundred volts here or there on a system. Solid state stuff gets really bothered when you have more than a few volts. You can't directly control high current (motors) with logic. You will still need something in-between. By the time you get it hooked up you will have a single SOT-23 IC and a whole bunch of protection on the inputs. The outputs will go to solid state relays. Those will need heatsinks on them since they are not as efficient as a mechanical relay. You also will need a regulated supply for the logic as well as the SSR drive.Bob

author: retrolefty
author_rank: Super Contributor
timestamp: July 11, 2016, 01:45:51 am
content: 24 volts, AC or DC? Also what is the maximum (locked rotor) current draw for the motor(s)?
Replacement 3-lug 1.6/10 connector - Page 1
Forum section: electronics / projects

author: veedub565
author_rank: Frequent Contributor
timestamp: August 22, 2021, 07:40:36 pm
content: Does anybody know if it's still possible to obtain a replacement one of these connecters (attached). It's for a W&G EPM-1 and a google search shows (at least at one end) it is a 3-lug 1.6/10 connector.You can see the female part of this connector is damaged and causing intermittant connection.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: August 22, 2021, 08:00:08 pm
content: 1.6-10 is correct, the other side (the W&G system connector) goes by the name 'Versacon'.Unfortunately for you, I have only 2 of those. Does it need to be the very same? Maybe some uncounted Versacon/BNC75 could turn up.

author: veedub565
author_rank: Frequent Contributor
timestamp: August 22, 2021, 08:08:09 pm
content: Ah thanks for confirming the W&G end of this connector (Versacon) I guess it doesn't matter if it's the very same, so long as it fits. I have the probes with the 3-lug 1.6/10 connector on them.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: August 23, 2021, 03:33:19 am
content: Quote from: veedub565 on August 22, 2021, 08:08:09 pmMaybe you misunderstood me. I might find a BNC (75R) adaptor for Versacon which is surplus to my requirements, but that would not help with your probes. But it would allow you to continue using the instrument where the adaptor comes from.

author: veedub565
author_rank: Frequent Contributor
timestamp: August 23, 2021, 08:33:21 am
content: Ah yes I think I did misunderstand you. A BNC (75R) for Versacon would be helpful if you can find one. I do have a 3-lug 1.6/10 to BNC adapter for the probes so i would be able to connect them.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: October 06, 2021, 02:02:47 am
content: Sorry, no luck yet in locating them. If it is pressing:https://www.ebay.de/itm/224223977277I would help with shipping if necessary.

author: veedub565
author_rank: Frequent Contributor
timestamp: October 06, 2021, 09:02:29 am
content: No problem, thanks for checking though. It's not pressing but I might purchase one of those ebay items
Replacement Caps - Page 1
Forum section: electronics / projects

author: veedub565
author_rank: Frequent Contributor
timestamp: December 18, 2019, 03:20:52 pm
content: I need to recap an old PSU, can somebody recommend a brand/series of capaciter and best place to buy from. I found the values I needed on RS but, not cheap and some are just general purpose series. I've read that FM, FC, FR series are good ? Values are100uF 50v47uF 50v470uF 35v330uF 50v1000uF 35v4000uF 15v (sprague can neg)An additional problem is that a lot of the newer capacitors for those values are a quite a bit smaller and the lead pitch is different so they don't fit the holes in the board. I'm guessing I can upsize capacitance/voltage rating a bit to get the right size.

author: VeryFastSnail
author_rank: Contributor
timestamp: December 18, 2019, 05:41:45 pm
content: I personally always buy more expensive caps. That ensurea that it’s quite a better quality caps, and about size, just bend the legs apart and solder it in holes... as precausion you can add heatsheink on exposed legs, but I never had a problem doing that...I would not up the voltage rating of caps just to make them fit, because it’s waste of money.

author: andy3055
author_rank: Super Contributor
timestamp: December 18, 2019, 05:54:04 pm
content: Quote from: VeryFastSnail on December 18, 2019, 05:41:45 pmYou must be a mind reader! Exactly the way I wanted to responded.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: December 18, 2019, 07:32:05 pm
content: I'll always raise the voltage on caps less than 25 volts. The higher voltage will have lower esr and generally be more reliable. I go for the better series of caps by well known manufacturers even if they cost a bit more. You'll be ahead in the long run. Be careful bending leads on electrolytic caps. You should grab them with thin pliers and make two bends. What you don't want is to spread the leads in the rubber end cap as that can damage the seal and lead to early failure.

author: veedub565
author_rank: Frequent Contributor
timestamp: December 19, 2019, 08:48:22 am
content: Thanks Guys, from an asthetic point of view I'd prefer to get capacitors with the right lead pitch if I can rather than bending leads. I know I know, nobody is going to see it.I'm guessing pretty much any modern electrolytic capacitor is going to have much better performance than ones from 30yrs ago. I shopped around and found some reasonably priced Nichicon PS & PX series ones. Slightly higher voltage so they match the lead pitch of the original's, 105deg rated. There is a spec for the ripple current, but I have no idea what the original requirement was. I'm assuming that these new ones will have at least an equal or better spec than the 30yr old OEM ones. being a higher voltage rating I would imagine the ripple rating is also greater.
Replacement connector options? - Page 1
Forum section: electronics / projects

author: UpLateGeek
author_rank: Contributor
timestamp: August 10, 2022, 02:08:33 pm
content: So I bought this [vintage computer] clone off the electronic bay, and it didn't come with a power supply. Unfortunately they decided not to use the same power connector as the original, so I'm having difficulty figuring out what to use as a replacement.To top things off, it looks like the pin spacing is totally weird. Measuring with my digital calipers it's closer to 4.8mm for the first 5 pins, then the last is 7.2mm. Which makes sense if it's a 1.5x gap, but I have no idea why they wouldn't use something more "standard" like 0.2". The pins themselves are 1.5mm diameter.Because connectors these days are all like "Easy-Trademark Series®" or "miniPatented 3.0+™", and only specify the pin spacing and not the diameter, it's not easy to find something using the parametric search. I did find a female connector contact from Molex called "Standard .062" 1561", but that's closer to 1.6mm, so it might not fit. And crimping a bunch of contacts onto the end of the wires and shoving them onto the pins isn't exactly the nicest solution, so if anyone has any ideas what I could use, feel free to make a suggestion.

author: ledtester
author_rank: Super Contributor
timestamp: August 10, 2022, 09:01:19 pm
content: How about just using your own connector?Use a wire header like you see in an ATX power supply: wires soldered to the pcb terminating in a header that you can then connect to mating header to your power supply.Desolder the current header if you can or solder wires to the bottom of the pcb or to the header pins.

author: tooki
author_rank: Super Contributor
timestamp: August 11, 2022, 06:04:42 am
content: Quote from: UpLateGeek on August 10, 2022, 02:08:33 pm”These days”?? It’s always been this way. When you start seeing generic descriptions (like “0.1” header”) it’s because it’s been around long enough for clone products to take over, and people forget the original name (like Bergstik in this example).Anyhow, that looks for all the world like a JST V connector: 1.55mm pin diameter, 5.0mm pitch with 7.5mm pitch on the first pin for keying.https://www.jst-mfg.com/product/index.php?series=258

author: UpLateGeek
author_rank: Contributor
timestamp: August 12, 2022, 01:05:05 pm
content: Quote from: tooki on August 11, 2022, 06:04:42 amBoom. Ordered.I knew I came to the right place! So thanks for your help, and hopefully the plug fits!

author: tooki
author_rank: Super Contributor
timestamp: August 12, 2022, 03:46:28 pm
content: You’re welcome! Let us know how it works out.
Replacement display - Page 1
Forum section: electronics / projects

author: TomS_
author_rank: Frequent Contributor
timestamp: February 19, 2018, 10:01:31 am
content: Hi everyone. Trying to find a replacement display for a piece of test equipment I have. It has taken a hit and the screen is completely blacked out (not as in it doesnt turn on, its just really smashed up).Attached are some photos. I can find what looks to be some similar displays by model number on Aliexpress, but the appear to have a wider flex with more pins (mine has 55, the others appear to be 60 or so). Finding this particular screen is proving very difficult.Markings on the rear of the display are:WZ-VGG3224A5-6UFLWA*101202/Y2googling for VGG3224A5 does produce some hits, but they appear to be mostly the same listing on Aliexpress on different regional websites.Hoping someone might know of better places to look, or perhaps you have one and would be willing to sell it? Or maybe you know of equivalent parts that would work?I'd really like to get this bit of gear working again, its a pricey optical fibre scope (for inspecting the face of connectors for dirt/grease/damage etc) with pricey attachments that I'd rather not have to replace.ThanksTom
replacement electrical part - Page 1
Forum section: electronics / projects

author: ovaifuwa
author_rank: Newbie
timestamp: January 04, 2022, 12:28:53 am
content: Can anyone help me find a similar part to this MPN: LTC3119EUFD#TRPBF. It is available on digikey but i need it on JLCPCB because I need it assembled. Any help would be appreciated or pointers towards finding another one. Thank you in advanceThe part is needed to step up a 11.1V output from a battery to a 12V output. I need the ouput current to be at least about 5A since i will be connecting a jetson xavier nx to it.https://www.digikey.ca/en/products/detail/analog-devices-inc/LTC3119EUFD-TRPBF/6412260** i should add that I am asking because i am not sure I am searching correctly for a similar part as i am new to this and learning as i am doing this. any help or pointers as to how to search for the right part will be appreciated**
Replacement for AD558 D/A converter - Page 1
Forum section: electronics / projects

author: perdrix
author_rank: Frequent Contributor
timestamp: August 10, 2025, 06:06:14 pm
content: This is quite a costly part at about USD15 or so. Is there anything cheaper that would work well as a substitute? There are so many D/A converters with different parameters that I'm rather struggling to identify any good candidates.ThanksDavid

author: xvr
author_rank: Frequent Contributor
timestamp: August 11, 2025, 05:08:44 pm
content: AD558 is a 45 year old chip. So it is expensive, like any antique.Use modern ADC - ANY of them will be better and cheaper.

author: perdrix
author_rank: Frequent Contributor
timestamp: August 15, 2025, 04:00:12 pm
content: Pin compatible?

author: xvr
author_rank: Frequent Contributor
timestamp: August 15, 2025, 04:16:30 pm
content: Quote from: perdrix on August 15, 2025, 04:00:12 pmNot, of course. If you need one-to-one replacement you have to buy AD558