hybridfree/eevblog-posts huggingface dataset:
What type of high contrast / daylight readable dot matrix display is this? - Page 1
Forum section: electronics / projects

author: Mike
author_rank: Newbie
timestamp: June 13, 2018, 08:55:37 am
content: I saw this display in a taxi (see attached pic). This display had a very high contrast and easily readable black on orange / yellow letters and number. It looked like a dot matrix type display.Is this OLED or is it some other kind of display?Can someone tell me where I can get this type of display?I would like to use such a display for diverse micro-controller projects.

author: capt bullshot
author_rank: Super Contributor
timestamp: June 13, 2018, 09:34:39 am
content: The picture isn't good enough to determine the display type, my guess would be a monochromatic high contrast LCD with high intensity LED backlight. These often are custom made to match customer specs.BTWhigh level pricing in NOK reminds me of my upcoming holiday trip to Norway

author: Mike
author_rank: Newbie
timestamp: June 14, 2018, 08:50:54 am
content: I found this company that seems to have something similar.https://www.lcd-module.com/products/olednew-technology.html#c2878Anyone know how how to drive this type of display and if an Arduino library exists?
What type of output pin can I share on a single GPIO - Page 1
Forum section: electronics / projects

author: drakejest
author_rank: Regular Contributor
timestamp: August 31, 2020, 03:09:07 pm
content: So i am very limited on my GPIO with only 4 remaining, and using a portexpander seems to be unecessary. I have used 2 ofthis ICand 2 ofthis ICAnd i need to read their status pins.On the first IC i only need to read there are in total of 4 status pins, i do not need to know which one triggered the status so i would like to read it only using one pin, the pins seems to be an open drain type, so is it possible to share this? hopefully they can also have only one pull up the schematic kinda lookinglike thisOn the second IC is a bit tricky since it takes 2 GPIO to read, 1 for selecting either channel and 1 for the actual reading, I could not identify what type of pins they though,this is my planned circuitIn total i have used 3 pins which leaves me 1 extra for whatever i might use it for.

author: bson
author_rank: Unknown
timestamp: August 31, 2020, 09:30:55 pm
content: Drive channel select directly using the GPIO output, no need for a pull-up since they're inputs.
What type of switch? - Page 1
Forum section: electronics / projects

author: simcop2387
author_rank: Contributor
timestamp: August 26, 2014, 05:57:30 am
content: I'm looking to make a tiny tiny space invaders game into a candy tin but I'm having trouble figuring out the controls. I think the same type of "rocker" that the DSO Quad uses might work well but i have no idea what to call it. Nor have I managed to find them on mouser yet.Here's the cabinet if you want to see. Found it on a road trip and decided I had to build it.(http://smile.amazon.com/Space-Invaders-Apple-Arcade-Cabinet/dp/B00B78E9G0/)

author: Yago
author_rank: Frequent Contributor
timestamp: August 26, 2014, 06:43:04 am
content: What a cool project !Would interested to see how it all goes, will you be posting progress?For the switch, might be possible to take some assembly from existing games consoles such as Nintendo DS etc.These are probably free as there will be many knackered ones about now.Another could be the volume rocker from a mobile phone or pad.

author: tautech
author_rank: Super Contributor
timestamp: August 26, 2014, 07:42:16 am
content: Are these what you are looking for?http://nz.mouser.com/Electromechanical/Switches/Multi-Directional-Switches/_/N-5g2z

author: simcop2387
author_rank: Contributor
timestamp: August 26, 2014, 06:29:23 pm
content: Quote from: tautech on August 26, 2014, 07:42:16 amYep there's several in there that are what I'm after! Now to just figure out which is the best.QuoteI plan on either putting it up on either hackaday.io or on my own site, I haven't decided yet. Either way I'll end up posting about it again here on the forums. The plan right now is to make it all fit in the top of the compartment (it's separated by the plastic bits that make up the screen in the tin) except for the battery which will go in the bottom where the candy is. Hoping to do it all with a 9V battery because of the size but might have to use something else just for current requirements.
What value is this capacitor? - Page 1
Forum section: electronics / projects

author: Refrigerator
author_rank: Super Contributor
timestamp: October 11, 2019, 08:31:04 am
content: I found a cracked cap in my SAAB DIC and would like to replace it before i get a new DIC.I think it's a 1µF 630V poly cap but i'm not sure and would appreciate some input.

author: tautech
author_rank: Super Contributor
timestamp: October 11, 2019, 08:38:18 am
content: Quote from: Refrigerator on October 11, 2019, 08:31:04 amYep that's how I read it too plus J tolerance.

author: MagicSmoker
author_rank: Super Contributor
timestamp: October 11, 2019, 09:58:47 am
content: Yep, it's a 1uF/630VDC/5% film cap likely made by TDK/EPCOS (blue color)... BUT... what could have caused a film capacitor to fail from what looks like internal overpressure? That's something you might expect that to happen to a heavily abused elko, not a film type, so if you are going to go to the trouble of depotting the module to replace the capacitor you should do a little more investigating to see what could have caused it to fail so spectacularly.

author: Refrigerator
author_rank: Super Contributor
timestamp: October 11, 2019, 10:26:46 am
content: Quote from: MagicSmoker on October 11, 2019, 09:58:47 amI just carved out the old cap and soldered on a new one to the legs of the old one, no way am i depotting the whole thing because it's rock hard epoxy.The DIC was made in 1998 and is bolted to the top of the hot cylinder head so i think that counts as some pretty good abuse.There have been plenty of bad X/Y class caps that split open, most made by RIFA.

author: MagicSmoker
author_rank: Super Contributor
timestamp: October 11, 2019, 10:34:30 am
content: Quote from: Refrigerator on October 11, 2019, 10:26:46 amOh, this thing is bolted to a hot engine? Yes, that certainly counts as abuse and so I'd agree this is likely a similar failure mode to those (infamous) Rifa "safety" capacitors - epoxy molding splits open and lets in water vapor that eventually does the poor capacitor in.
What value is this resistor? - Page 1
Forum section: electronics / projects

author: Bud
author_rank: Super Contributor
timestamp: April 19, 2019, 03:10:27 am
content: The one on the left, what value is it?

author: helius
author_rank: Super Contributor
timestamp: April 19, 2019, 03:16:48 am
content: Should be 2M2.

author: David Hess
author_rank: Super Contributor
timestamp: April 19, 2019, 06:57:48 pm
content: 2.2 * 10^5 or 2.2 megohms.
What will this little device do? - Page 1
Forum section: electronics / projects

author: Merlysys
author_rank: Regular Contributor
timestamp: May 25, 2016, 07:57:38 pm
content: It is to make back up camera and display work in the car.Input is 12 volts from car battery, output is same voltage.I tested and got those results so could it be some sort of filter?What kind of waveform can I input to see it doing what it was supposed to do?

author: fcb
author_rank: Super Contributor
timestamp: May 25, 2016, 08:15:30 pm
content: Probably just a big inductor (choke), or at best a double balanced choke. The electrolytic forms a filter.You won't see much of a 'waveform' unless you have a noisy car - it'll be difficult to 'scope both the input and output simultaneously in a meaningful way, but if you could, you'd hopefully see higher frequency noise on the output would be attenuated significantly.

author: danadak
author_rank: Super Contributor
timestamp: May 25, 2016, 08:17:36 pm
content: Picture of board bottom would help.Looks like diode is for input polarity protection.Could it be a buck/boost regulator that always provides 12V if battery is below or above 12V.Could be a simple transient suppressor (if transformer actually an inductor) for load dump.Would have to see either schematic or part number for what the device is sandwiched between big cap and transformer/inductor.Regards, Dana.
What would be a good clear adhesive for this? - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: February 07, 2014, 02:00:58 pm
content: Hi Everyone,I love LED displays, segments and matrix, etc. One thing that is often annoying is that when off, the led looks different than the background color (where there are no LED's). I notice that some have a darker background and some have a medium gray background (trying to be closer to the color of the LED when off), etc.If I get some material that is tinted like you see for the covers of VFD displays, etc., is there an easy way to glue this directly to the top of a led module? I'm thinking about a clear type adhesive that wouldn't get in the way of visibility. Maybe you could cut a small square of the tinting material out and then roll an even sheet of adhesive on it, etc. Any other ideas?I've tried some car window tint that I got from a company who does it and it is thin, fills in the bumps of the LED's, etc. It does make the LED and background surface look the same, but isn't flat and professional looking...Thanks,Alan

author: staxquad
author_rank: Frequent Contributor
timestamp: February 07, 2014, 02:41:07 pm
content: Lens cement could be a possibility, Canada balsam dissolved in xylene.

author: calzap
author_rank: Frequent Contributor
timestamp: February 07, 2014, 04:07:08 pm
content: Trying to adhere two flat (or tangential surfaces) and maintaining transparency can be tricky. Biggest problems are air bubbles and Newton's rings. There are lots of tricks to avoid these (vacuum chambers, pressure chambers, rollers, clamps, ovens, etc.), and the ones to use depend on the chemical and mechanical natures of the two surfaces to be adhered and the equipment available. Good luck if any of the surfaces are fluorocarbons or polyallomers (polyethylene, polypropylene, etc.). If an air gap is allowable between the two surfaces, then the process is simpler. You can use perimeter blobs or ridges of thick adhesive, like hot snot or silicone, or a solid frame of metal or plastic with mechanical fasteners. Tinted acrylic sheet would be good choice; it's readily available in lots of colors and thicknesses.Mike in California
What's a lightweight, cheap circuit for providing 12v, ~4v, 5v on a Quadcopter? - Page 1
Forum section: electronics / projects

author: salil
author_rank: Regular Contributor
timestamp: May 30, 2015, 03:47:29 am
content: I'm looking to run all my extra stuff like GoPro camera (3.7-4.2v),TS832FPV transmitter (12v) and possibly some 5v USB device in the future on a DJI Phantom 2 I'm in the process of modding from used Phantom 2 guts (parts) I've salvaged on the cheap. I haven't invested in GoPro Hero 4 batteries and I would imagine that it would be ideal to run all onboard devices off the single 5200 mAh 3S 20c li-po pack (possibly up to 6000 mAh in the future) in order to have less batteries to worry about charging/dying, save weight and add flexibility to power other low current devices in the future.I have a couple cheapregulated dc boost/buck converters I won on eBaya while ago for basically nothing, but I'd need one for each voltage, which would take up some extra space and weight from the redundant components.With the exception of the GoPro Hero 4 Black (draws at most 1.5A, I would guess), I don't anticipate any devices drawing more than 0.5A. Does anyone have suggestions for a circuit that can simultaneously output multiple voltages, is lightweight and economical or am I better of just mounting a bunch of cheap regulated buck/boost converters as mentioned above?

author: SL4P
author_rank: Super Contributor
timestamp: May 30, 2015, 06:08:46 am
content: To some extent it depends on the current you need at each voltage.Youcouldregulate each supply individually, or use a simple divider if (I) is low enough.If the 12v current is low enough - yu might use a buck converter from the primary dirty 5V, but the problem relates closely to the length of string, and what your main power source is.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 30, 2015, 09:46:25 pm
content: I suppose the "12V" stuff goes directly to the battery, (and I suggest a filter for that), in the hobby world voltage regulators are called BECs, battery eliminator circuit, from the bad old days when the receiver and the servos had separate batteries and driving both from one battery was a revolution...http://hobbyking.com/hobbyking/store/__767__766__SBEC_UBEC_Regulator-SBEC_UBEC.htmlhttp://hobbyking.com/hobbyking/store/__68126__L_C_Power_Filter_0_7A.htmlHK looks like a good deal until you get into the shipping, it's best to make monster orders and try to get what you need in a big batch, and put lipos separately.Also it's a good idea to shop by weight for quadcopter stuff. I tried to get my boat stuff to fly and it didn't work very well.
What's Inside: Teardown of a Temperature and Humidity Sensor - Page 1
Forum section: electronics / projects

author: electronupdate
author_rank: Regular Contributor
timestamp: April 29, 2015, 02:33:50 pm
content: I bought a "Amsong AM2302/DHT22" temperature and humidity sensor off ebay... all of $4.00. It works as advertised and it was very capable for the tiny amount of money involved.Curiosity got the better of me so I de-capped the part. It still amazes me how much technology one can buy for so little money... it's basically a little micro-processor controlled measurement unit.

author: SeanB
author_rank: Super Contributor
timestamp: April 29, 2015, 07:24:30 pm
content: Very nice, and nice to see the SMD resistor trim as well. You can see it on pretty much any resistor under the black coating as lines. IIRC the larger ones are done by grinding away material with fine silica sand in air blasts or with a grinding wheel, and the smaller ones are laser. Takes a millisecond to read the resistance, and then do a preset one of a few cuts to get the value in tolerance. Then you do a random sampling of them to see if you have the right value spread. Might take a half second in total during production, and you can get a tight tolerance ( and they all will be trending to one side or the other of nominal during a batch) on them. Screen printed resistors that are not trimmed typically have a 10% tolerance in value, and this will vary from each time you swipe the resistive ink across the screen in production.

author: rsjsouza
author_rank: Super Contributor
timestamp: April 29, 2015, 07:43:29 pm
content: Good video; thumbs upped!

author: Puch-Maxi
author_rank: Newbie
timestamp: April 29, 2015, 08:25:56 pm
content: Thanks for sharing, very interesting indeed!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 29, 2015, 10:46:15 pm
content: Your voice reminds me of Nurdrage...What's this? Nitric (or sulfuric) acid? Not part of the usual engineer's kit...Tim

author: helius
author_rank: Super Contributor
timestamp: May 08, 2015, 07:48:32 pm
content: Very interesting, and thanks for posting about it.I was looking at theTI HDC1000 RH sensor, but now it looks like I can evaluate the DHT22 as well.

author: Dragon88
author_rank: Regular Contributor
timestamp: May 09, 2015, 12:55:23 am
content: Good video, I subscribed. Thanks.
What's the best company for low volume, quick turn around PCB assembly? - Page 1
Forum section: electronics / projects

author: billthebuilder
author_rank: Contributor
timestamp: October 30, 2015, 08:16:08 pm
content: What's the best company for low volume, quick turn around PCB assembly?Why do you choose their service over others?What's the ballpark cost for 10 3"x3" boards assembled?How quick can they be, from sending BOM to the package arriving?Thanks,Bill

author: marshallh
author_rank: Unknown
timestamp: October 30, 2015, 10:10:20 pm
content: Typical numbers for a not-shady Chinese outfit:$1500 NRE, setup$5-15 assembly cost per boardParts cost is BOM + 10% for overagesTurn time can be 3-5 weeks.American numbers will be 3-5 times higher.

author: krivx
author_rank: Frequent Contributor
timestamp: October 30, 2015, 10:16:38 pm
content: Quote from: marshallh on October 30, 2015, 10:10:20 pmI'm a little surprised by that setup cost, is that for a complex board?

author: nctnico
author_rank: Super Contributor
timestamp: October 30, 2015, 10:17:46 pm
content: I agree. That sounds way too high!

author: IconicPCB
author_rank: Super Contributor
timestamp: October 31, 2015, 05:31:15 am
content: Billthebuilder,email the BOM for a competitive quote.In another thread You were however saying you had a P&P machine of your own ..or did I misunderstand Your comments?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 31, 2015, 05:33:35 am
content: American protos will run in the $5k range for commercially useful turn times (say 2 weeks).Tim

author: calexanian
author_rank: Super Contributor
timestamp: October 31, 2015, 03:47:44 pm
content: Only 10 pieces? Why not just assemble them yourself? If you don't want to bother I think you would be a good candidate for Advanced Circuits turnkey option. They are in Colorado.Here is a linkhttp://www.4pcb.com/Assembly-Services.htmlbe sure to ask for the new customer discount.We use them for all of our quick turn boards and have had very good luck. We have never used their assembly services because we are all in house assembly but I have seen samples and they look legit.

author: tonyarkles
author_rank: Regular Contributor
timestamp: October 31, 2015, 04:51:12 pm
content: Check out macrofab.net. They're based in Austin, TX, and I've had fantastic luck with them. Their quick-turn (5 day) service adds about $1,000 to the price, but that's not bad at all. You just upload your Eagle or Gerbers, an XYRS for pick & place, and a BOM. They'll order the parts for you, fab the boards, and do the PCBA. You can play with the numbers right in the web interface to see how much it'll cost for different quantities.Honestly, for my business, they've changed everything. I used to order prototype boards from China with all of the expedited options, and then do hand assembly in-house. Now I just send them off to Macrofab.I don't mean for this to sound like an ad, but I've used their service more than once and am super super happy with them.
What's the biggest, most powerful, highest voltage flyback transformer here? - Page 1
Forum section: electronics / projects

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 23, 2018, 01:19:09 am
content: https://www.ebay.com/itm/Flyback-Transformer-1-439-SERIES-for-Sony-TV-Monitor-Assorted-Numbers-US-Seller/122062948466?_trkparms=pageci%3Abbd3079e-1836-11e8-8a77-74dbd180fc9e%7Cparentrq%3Ac038bca91610aadccbd0a5b9fff12806%7Ciid%3A1&_trksid=p2481888.c100675.m4236Don't worry, they will be in good hands

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 23, 2018, 02:06:48 am
content: Most likely X-ray flybacks would be the most powerful.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 23, 2018, 02:15:08 am
content: Funny you should mention that, I was looking for answers from that listing only, but I am using whatever the answer is to build an x-ray psu by using them in series (I know how). Any help (from the ebay listing only please).

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 23, 2018, 02:42:52 am
content: Use automotive ignition transformers and a voltage multiplier.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 23, 2018, 03:22:23 am
content: Read above post. Thanks.
What's the purpose for these extra pads (LMX9838 bluetooth module) - Page 1
Forum section: electronics / projects

author: miguelvp
author_rank: Super Contributor
timestamp: March 09, 2015, 01:15:26 pm
content: So I've purchase this module from our member blueskull and it's in transit here.By looking at the datasheet I noticed the footprint has a lot of internal pads but they are not connected and the datasheet warns not to place any pads (which is good for me because that would be a pain to solder)My question is, why did they even put those pads there if they are not connected and are not supposed to be soldered either?Is it a heat dissipation thing? but then the pads would help, so I'm not sure what is their purpose at all. Anyone?pdf:http://www.ti.com/lit/ds/symlink/lmx9838.pdf

author: 6thimage
author_rank: Regular Contributor
timestamp: March 09, 2015, 01:47:17 pm
content: I doubt they would be for heat dissipation - they would be connected to a ground plane if they were. My guess is that they are used for programming and testing the module during manufacture, but I can't see why they wouldn't just use the normal pins for that.

author: SeanB
author_rank: Super Contributor
timestamp: March 09, 2015, 04:41:26 pm
content: I would bet that is the through holes for the BGA package on the module. Multilayer board with a BGA package on it, and having through holes at each ball makes it easy to check all the balls did reflow during production.I would make sure that the board you solder it to in final use does not have any copper in this area, keep it as blank PCB with either a solder mask only or use it for silkscreening a batch number or other internal control number that you will not use after it is assembled.

author: miguelvp
author_rank: Super Contributor
timestamp: March 10, 2015, 04:50:59 am
content: Thank SeanB,That makes perfect sense, specially seeing that the footprint is asymmetrical from the chip itself and 1/4th overhangs the pin-out. So it seems they have a full circuit inside the chip with sub-modules.
what's the TrueArb technology? - Page 1
Forum section: electronics / projects

author: xzswq21
author_rank: Frequent Contributor
timestamp: November 08, 2017, 07:51:32 pm
content: Hellowhat's the difference between the DDS and TrueArb?I couldn't find anything about it!would you please refer me to some papers or references?i want to work it in details.Best Regards

author: jpb
author_rank: Super Contributor
timestamp: November 08, 2017, 08:26:15 pm
content: Keysight have several papers on it. (I presume that you mean TruForm - or perhaps TruArb is a rival technology).Basically they interpolate/resample in real time to give very low jitter compared to standard DDS which has a fixed sample rate.This is a good (if old) paper on the general subject:https://m.eet.com/media/1128699/12978-choosing_a_waveform_generator_the_devil_is_in_the_details.pdfan overview by Keysight:http://literature.cdn.keysight.com/litweb/pdf/5991-0852EN.pdf?id=2224576

author: tautech
author_rank: Super Contributor
timestamp: November 08, 2017, 08:34:21 pm
content: TruArb is Siglent's architecture and it delivers better signal fidelity than DDS.You can read a little more about it here:http://www.siglentamerica.com/prodcut-detailxx.aspx?id=1364&tid=16&T=2
What's this part? (SOLVED) - Page 1
Forum section: electronics / projects

author: The Soulman
author_rank: Super Contributor
timestamp: June 07, 2017, 12:09:17 pm
content: Would likely be acomparator.Its a multiplexer/de-multiplexer.

author: Dr.Rob
author_rank: Newbie
timestamp: June 07, 2017, 12:20:13 pm
content: This might be of interest ... or I could be completely wrong.http://www.intersil.com/content/dam/Intersil/documents/isl8/isl84051-52-53.pdfRob

author: The Soulman
author_rank: Super Contributor
timestamp: June 07, 2017, 12:25:32 pm
content: That is it! Thanks.From the datasheet:Quote
What's this part? "54?" SOT23-6 in a SAT multiswitch - Page 1
Forum section: electronics / projects

author: Yansi
author_rank: Super Contributor
timestamp: June 19, 2016, 04:25:56 pm
content: Hello,just being curious and salvaging usable interesting parts. ...currently dismantling and old SATellite multiswitch thingy...There is some SOT23-6 part labeled "54?" (5 4 and a triangle). Looks like some MMIC amplifier. If you look on the photo, and the left upper leg is #1, then legs 2, 4 and 5 are ground. The photo is not clear, sorry, the parts are located in a badly accessible place and covered with a little dust.There is also a fuckton of SOD323 diodes for channel switching. They are marked "AG" (Left bottom corner of the photo). I've identified them being possibly a ZMV835ATA varactor diode. But seems strange to me to use a varactor diode in a switching circuit. Is it possible?Thank you for help,Yan
What/How are stencil frames used? - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: July 03, 2015, 01:19:58 pm
content: So far I've done a couple of pcbs with a flat kapton stencil. I've got a metal one coming from elecrow to try next. For these flat ones I just use some masking tape to stick them to a metal work surface I use. What is the deal with the framed stencils? How would one use them differently? What is their purpose?

author: 8086
author_rank: Super Contributor
timestamp: July 03, 2015, 02:03:23 pm
content: They're used in machines that apply paste to the boards automatically. Not much use for manual pasting.

author: janekm
author_rank: Unknown
timestamp: July 03, 2015, 03:44:32 pm
content: There are also "plain" aluminium frames that the metal stencil is stretched onto. This keeps the stencil flat to the PCB, and is convenient for manual paste application too. Those are the standard in China (and remarkably cheap) but awkward to ship outside China.

author: alank2
author_rank: Super Contributor
timestamp: July 03, 2015, 05:10:33 pm
content: Thanks for the explanations.
What's going on in this LC power filter used with FPV drone cameras? - Page 1
Forum section: electronics / projects

author: ledtester
author_rank: Super Contributor
timestamp: October 23, 2020, 01:21:40 am
content: I'm curious what might be going on with this LC power filter (note both the front and back sides of the board):https://alexnld.com/product/10pcs-l-c-power-filter-2a-rtf-lc-filter-3amp-2-4s-lc-module-lllustrated-eliminate-moire-video-signal-filtering/What is that IR chip on the back and how is it being used?Thanks!

author: uer166
author_rank: Super Contributor
timestamp: October 23, 2020, 02:15:57 am
content: It's a MOSFET:https://www.infineon.com/dgdl/irf9335pbf.pdf?fileId=5546d462533600a40153561147881da3.Probably used as reverse polarity protection in case someone plugs it in wrong.
What's going on with Toshiba MOSFET prices? - Page 1
Forum section: electronics / projects

author: jbay
author_rank: Newbie
timestamp: August 28, 2020, 01:03:27 am
content: Hi all,Sorry I'm fairly new here and not sure if there's a better forum for parts-and-purchasing related discussion. I didn't think it quite fit in as manufacturing...Anyway, I noticed today that a whole slew of Toshiba power MOSFETs have approximatelydoubledin price compared with the last time I checked (a couple months ago) from Digikey, Mouser, etc. By comparison, similar MOSFETs from manufacturers like TI, Diodes Inc, Nexperia, etc. have either stayed the same or dropped by a small percentage, so it doesn't seem to be caused by something like a global demand surge or inflation. I know that component price swings are common in the electronics industry but doubling in a few months for commodity parts seems unusual.Has something been happening recently at Toshiba Semiconductor and Storage that's causing a disruption for them? Were they hit harder than everyone else by COVID shutdowns or something? Does anyone here have access to a price history tool that can verify this?For example (numbers are for 1000 pc quantities), TPN2R903PL and TPN7R006PL both used to be $0.15167 at Digikey and now they're $0.304; TPH1R204PB used to be $0.31287 and now it's $0.60175, and so on.
What’s inside an oscillator module? - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: September 21, 2021, 12:10:33 am
content: Anyone know what’s inside one of these tiny 4MHz 4mm x 7mm oscillator modules? Roughly what freq crystal and how long a divider chain? And how accurate is a random Chinese one likely to be? No dire need to know these things, just wondering.

author: james_s
author_rank: Super Contributor
timestamp: September 21, 2021, 12:19:09 am
content: I saw a youtube video some time back of someone dissecting one.I think this was it:From my limited experience, accuracy is pretty good on the ones I've used, comparable to any other typical crystal. The temperature compensated ones are substantially better.
Whats micros are inside the digital watches, ASICs? - Page 1
Forum section: electronics / projects

author: rvalente
author_rank: Frequent Contributor
timestamp: April 15, 2019, 01:22:46 pm
content: Hello Mates,I wonder, what micros are inside the classics digital watches? Lets take the famous casio F91W.Do you guys have any information on that?
Whats the craziest you've run a mosfet in avalanche? (or seen run?) - Page 1
Forum section: electronics / projects

author: cur8xgo
author_rank: Regular Contributor
timestamp: June 04, 2019, 12:10:22 am
content: How much power have you seen dissipated in avalanche in a mosfet in a working design, intentionally?Lots of big TO-247 fets out there are explicitly thermally limited for avalanche so the sky is the limit basically. Wondering whats been done. (and why its been done)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 04, 2019, 12:36:50 am
content: No idea. I don't look at a lot of bad designs in enough detail to know that. I avoid using avalanche in my designs, if at all possible.Some examples I can think of, mostly use terrifically slow switching to avoid avalanche in the first place. Replacing bad with worse, but if it works in the average case, they'll go ahead and sell it...Tim

author: cur8xgo
author_rank: Regular Contributor
timestamp: June 04, 2019, 01:33:18 am
content: Why is using avalanche bad design? Vishay has made it clear which of their fets are designed for it and those are limited only thermally. Makes an inexpensive and simple way to snub switching transients, since when its a factor you probably already have huge heat sinks on the fets.https://www.vishay.com/docs/90160/an1005.pdf

author: MagicSmoker
author_rank: Super Contributor
timestamp: June 04, 2019, 11:55:13 am
content: Quote from: cur8xgo on June 04, 2019, 01:33:18 amAvalanche is perfectly fine *if* the source impedance and/or the peak current is limited; if not, then device destruction is likely. Generally, avalanching a transistor (of any flavor) is only done when the fastest possible demagnetization is required switching an inductive load (think relays, contactors and the like; not transformers, except for old-style "transistorized" Kettering ignition systems).
What's the difference between these two thermistors? - Page 1
Forum section: electronics / projects

author: paul8f
author_rank: Regular Contributor
timestamp: August 23, 2020, 09:06:51 am
content: The type required:NTC MF52A10K, B=3950, 5%The nearest match I can find:NTC MF52D10K, B=3950, 1%Is the nearest match a good substitute component?Thanks.

author: Gyro
author_rank: Super Contributor
timestamp: August 23, 2020, 10:14:06 am
content: From the look of it, the letter specifies the tolerance. In which case, the 1% part would substitute just fine for the 5% part (not the other way round of course).It would be best to find and double check with the datasheet though.

author: paul8f
author_rank: Regular Contributor
timestamp: August 25, 2020, 09:50:01 am
content: Thanks Chris,it's been so long since I've had a chance to do anything with this repair, that I asked the wrong question!(The A version has tin plated copper wire, while the D version has PVC insulated wire.)So, my question should have been... what's the performance difference between the two? Or is it irrelevant for an everyday appliance that never goes over 70deg C?

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 26, 2020, 04:59:03 pm
content: Straight copper wire type is for PCB mounting.PVC-isolated wires are (flexible) for mounting the thermistor somewere on a distance, for example to the heatsink.'A' and 'D' may mean different in different manufacturers so it could be easier if you put correct datasheet at first post.

author: Gyro
author_rank: Super Contributor
timestamp: August 26, 2020, 06:33:59 pm
content: Quote from: paul8f on August 25, 2020, 09:50:01 amAh, I wondered why there would be so many letters different between a 5% part and a 1% one.It's hard to say without having some context of where it is to be installed, is it replacing an existing part etc. - presumably the length of the bare Tin plated copper leads would be shorter than PVC flex ones. The datasheet ought to give a maximum temperature rating for the PVC leaded part (70'C is at my personal limit of what I would be comfortable using PVC for extended periods).The effect of the different lead types (heat conducted away from the thermistor) depends on the lead length and how well the thermistor is coupled to what it is monitoring.Pictures would help.
what's the led drive chip in pololu Reflectance Sensor Array? - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 11, 2023, 03:38:36 pm
content: HiI wonder what they have used for their Reflectance Sensor Array as the led driver, in the picture's it seems there is ak622markings on the chip, here you can see their data sheethttps://www.pololu.com/file/0J1558/qtr-qtrx-hd-reflectance-sensor-array-schematic.pdf

author: mariush
author_rank: Super Contributor
timestamp: November 11, 2023, 04:13:13 pm
content: Well, you know it's 2 channel driver, you know the current output (32mA per driver), you know it's linear because there's no inductors or other stuff on the circuit board, so you could go to distributors of components and filter based on that.It could be FAN5622 :https://www.onsemi.com/pdf/datasheet/fan5626-d.pdf

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 12, 2023, 11:35:49 am
content: thanks marius, it seems it FAN5622
What's the point of connecting this to the NFBL line instead of ground in LTP PI - Page 1
Forum section: electronics / projects

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: May 11, 2021, 06:05:39 am
content: I was looking at this circuit for the Fender Super Six Reverb amp, and the PI looks like a regular Long Tail Pair one, but there's this network going from the inverted output to the NFBL line on the PI...What's the point of connecting it there, instead of just ground? does this work like additional NFB from the output to the output tubes, unrelated to the NFB from output to PI cathode?[ Attachment Invalid Or Does Not Exist ]
What's the purpose of this grounding circuit? - Page 1
Forum section: electronics / projects

author: XaviPacheco
author_rank: Regular Contributor
timestamp: July 06, 2018, 05:46:51 pm
content: Hi,I've attached a circuit which I decoded from 1-phase drive used to control a 3 phase motor. The drive is fed from 120VAC. The ground from 120VAC is connected as shown in the schematic. It goes through a RC network to another ground of the circuit. The drive has two different grounds. What's the real purpose of this arrangement?

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 06, 2018, 07:07:09 pm
content: To stop ground loops, but provide a low impedance path for EMI and a path for static to dissipate.
What's the schematic symbol for a wire nut? - Page 1
Forum section: electronics / projects

author: Rasterist
author_rank: Contributor
timestamp: November 15, 2020, 07:32:51 pm
content: I'm working on a project where I'd like to join several grounds together with a wire nut. Is there a schematic symbol for that?

author: pwlps
author_rank: Frequent Contributor
timestamp: November 15, 2020, 07:43:21 pm
content: The wire nut won't be on the PCB so you don't need a symbol, take a 1-pin connector with a minimum footprint.

author: coppercone2
author_rank: Super Contributor
timestamp: November 15, 2020, 07:46:23 pm
content: you need to draw your own things for those levels of abstraction on wiring chart, its basically like being a cartoonist at this point without clear standards or guidelines. you need to draw them as you think your audience wants to see them.This is what I see1) lazy/strict documentation : normal industrial wiring diagram is shown (as in a motor and a drive) with footnotes about what connectors are appropriate (send to the most advanced users). This feels like getting a balonga sandwich. Yea whatever dude, take your gruel and go.2) more creative/thoughtful documentation : some kind of clear caricature is drawn of the connector to be used. (has more mass market appeal). Usually the advanced users won't complain because its a sight for sore eyes to see someone draw anything but a dot and hit a typewriter. I prefer this kind. Also since you see it on the paper you are WAY less likely to get a support question or have people mess it up (its hard to fuck up copying a picture). This is kinda fancy and more nutritious.If someone tried to define a international or even national symbol for a wiring nut, the confusion would be hilarious.
What's the smallest switch that can switch 1 mA of mains AC? - Page 1
Forum section: electronics / projects

author: Morad Tamer
author_rank: Contributor
timestamp: October 18, 2024, 10:46:04 pm
content: I'm trying to make a mains AC sensor through a big resistive ladder with output to input ratio of 1:10 (4*100k then a 47k). this then is passed over to a rectifier than a capacitor then to a mosfet which would pull some digital IO low when the mains AC input is present.The whole circuit uses about 1 mA of current.Now, is there a switch capable of handeling 250VAC mains that is not quite bigger than the circuit it self?I'm using 0805 resistors and SOT23 packages. I initially thought of using a DIP switch but found none rated for more than 50VDC.

author: Benta
author_rank: Super Contributor
timestamp: October 18, 2024, 11:00:46 pm
content: I understand your "mains present" sensor, but don't understand the switch. Where does that come in?The main thing about mains switches is preventing injuring or killing people, so a certain size for isolation and creepage is necessary.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 19, 2024, 04:11:52 am
content: How about an optoisolated triac driver?

author: mariush
author_rank: Super Contributor
timestamp: October 19, 2024, 04:21:52 am
content: you could probably use a neon bulb and a small solar cell ... or rectify with diode followed by resistor to drop some voltage and smooth with capacitor, into an optocoupler.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 19, 2024, 04:34:49 am
content: Quote from: Morad Tamer on October 18, 2024, 10:46:04 pmYou need to clarify how and when the user activates this mechanical switch ?Since you looked at DIP SW, it looks like you do not want momentary.

author: dmendesf
author_rank: Frequent Contributor
timestamp: October 19, 2024, 12:49:02 pm
content: An Optomos Relay:https://www.digikey.com/en/products/filter/solid-state-relays-ssr/183?s=N4IgTCBcDaIPIAcAuB7AtigzgAgE4FMAbAQwE9MQBdAXyA
Whats this connector? - Page 1
Forum section: electronics / projects

author: cnt
author_rank: Contributor
timestamp: January 19, 2022, 11:32:18 pm
content: I'm working on a project for pre, and post gas flow for a welder that has manual control right now. Rather than cut into the cable, I want to make an inline connection with the foot pedal so I need to find the right connector. The OEM connector costs 80$ and the other gender isn't really available without cutting up another foot pedal. Can anyone help me identify the original maker/part number or style name for this connector?You can buy it under the name amptrol pedal connector (amptrol is some welder company trademark word for potentiometer on a foot pedal).https://www.amazon.com/Lincoln-Foot-Amptrol-Adapter-K4104-1/dp/B010MZSQO4

author: coromonadalix
author_rank: Super Contributor
timestamp: January 20, 2022, 01:19:59 am
content: looks liek a din 6 connector ?? but for a thing like this you need to measure the pins spacing, the diameter of the inner shell, of the outer shell etc ....since its a chassis mount connector you can substitue it for your own ?? could cost less in the end ??

author: themadhippy
author_rank: Super Contributor
timestamp: January 20, 2022, 01:54:14 am
content: Quoteok not oem,but both genders for half of thathttps://usaweld.com/products/usaweld-replacement-6-pin-remote-amptrol-foot-pedal-connectors-for-lincoln-welders?variant=31493370871891

author: cnt
author_rank: Contributor
timestamp: January 20, 2022, 04:38:01 am
content: ah! excellent. short of finding out its a cheap commodity connector, this is a lot better!
What's this small, "free coil" over a pin component? - Page 1
Forum section: electronics / projects

author: mcinque
author_rank: Unknown
timestamp: November 14, 2020, 07:22:54 pm
content: I found this in a Xytronic soldering iron stylus.The central pin was connected to one side of the thermocouple.The free coil was connected to a wire connected to the electronic board.The coil isn't connected to the central pin.Did you ever seen this kind of component?What is it for? Some kind of capacitive sensing?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 14, 2020, 07:39:16 pm
content: It would also probably pick up vibrations or acceleration, such as movement... The spring would contact the inner pin.

author: Benta
author_rank: Super Contributor
timestamp: November 14, 2020, 08:23:15 pm
content: Movement sensor. When the iron is in its holder, it switches to stand by power. As soon as you pick it up, it goes to the preset power/temperature.Not really a power saving feature, but it prevents the tips from oxidising too much.

author: mcinque
author_rank: Unknown
timestamp: November 14, 2020, 08:53:28 pm
content: Quote from: Alex Eisenhut on November 14, 2020, 07:39:16 pmQuote from: Benta on November 14, 2020, 08:23:15 pmYou are right. If not moved for a while, the soldering iron lowers the tip temperature to 100°C.Thanks! I never saw that kind of component.
What's this thing? Inside a USB wall-wart. - Page 1
Forum section: electronics / projects

author: liteyear
author_rank: Regular Contributor
timestamp: July 24, 2024, 03:07:02 am
content: Any guesses what this is? The PCB is from a mains powered USB-C power supply.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 24, 2024, 05:00:47 am
content: Hard to tell. Maybe post a side view as well? What does the silkscreen marking for it say?Is it an inductor? Looks a bit melted though.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 24, 2024, 05:16:46 am
content: If what I'm seeing is an extension of the bobbin, that's triple-insulated wire for the secondary, and extra clearance for isolation (reinforced type is required between hazardous mains wiring and touchable SELF (safe extremely low voltage).It could also be wires wrapped around a ferrite bead, or some sort of semiconductor or molded chunk that we need more angles on. It's not a very descriptive angle here.Tim

author: liteyear
author_rank: Regular Contributor
timestamp: July 26, 2024, 10:39:44 pm
content: Thanks folks. No further photos unfortunately so a bit of a mystery. A form to create clearance makes some sense.

author: CaptDon
author_rank: Super Contributor
timestamp: July 27, 2024, 01:52:15 am
content: By its location it may be a bridge rectifier made from two devices, one being common anode and one being common cathode with plyobond glue for stability physical support.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 27, 2024, 02:50:39 am
content: Is there any regulator on this thing?

author: colorburst
author_rank: Regular Contributor
timestamp: July 27, 2024, 04:50:33 am
content: Tim is correct, here is a picture of a similar transformer:

author: BrokenYugo
author_rank: Super Contributor
timestamp: July 27, 2024, 12:55:35 pm
content: The triple insulated wire usually has that color to it. It's a quick way to see if a small SMPS is safe, if they used a proper transformer everything else will probably be good too.
whats this transistor? - Page 1
Forum section: electronics / projects

author: pinballtoys
author_rank: Newbie
timestamp: May 24, 2022, 10:55:23 am
content: hello allwas looking to replace this transistor but not sure what to order?i can see its made by Vitelic and looks to be an NPN with ECB pinout but I'm struggling to find its full part numberit switches a 240V relays and suspect a MPSA42 may do the trick but the pinout is different.Anyone have some suggestions please?Bobhttps://www.dropbox.com/s/kcb7rakxpwdmziv/transistor%20%281%29.jpg?dl=0

author: wraper
author_rank: Unknown
timestamp: May 24, 2022, 11:00:23 am
content: It's certainly has ST logo, not Vitelic.

author: wraper
author_rank: Unknown
timestamp: May 24, 2022, 11:03:58 am
content: It's STBV42https://www.st.com/resource/en/datasheet/stbv42.pdf

author: Benta
author_rank: Super Contributor
timestamp: May 24, 2022, 11:04:19 am
content: Yes, ST.More likely a triac.

author: wraper
author_rank: Unknown
timestamp: May 24, 2022, 11:06:29 am
content: And you should have cleaned the part with alcohol. Since "B" in BV42 marking as basically invisible.

author: pinballtoys
author_rank: Newbie
timestamp: May 24, 2022, 11:24:14 am
content: thanks so muchI'm in the UK and would normally buy from RS components, but it looks like this device went obsolete some time ago!

author: Zero999
author_rank: Super Contributor
timestamp: May 24, 2022, 12:20:02 pm
content: Are the relays run off AC, or DC? That will enable to determine whether it's a TRIAC or BJT.

author: pinballtoys
author_rank: Newbie
timestamp: May 24, 2022, 12:26:23 pm
content: looks like mains is half-wave rectified so assume its a transistorIMG_20220429_0002.pdf(514.46 kB - downloaded 102 times.)

author: gamalot
author_rank: Super Contributor
timestamp: May 24, 2022, 12:30:41 pm
content: Quote from: wraper on May 24, 2022, 11:03:58 amI seconded, it's definitely STBV42

author: pinballtoys
author_rank: Newbie
timestamp: May 24, 2022, 12:37:51 pm
content: this is the circuit board I'm trying to repair, the problem being RLB is not switching on!i thought i'd found the problem with capacitor C2 that had a high ESR but fitted new cap and problem persistsnot sure how this works?i can see that RLA is permanently on and even though half-wave supplied C1 ensure it stays on
Whats with all the Chinese Agilent 34401a meters for sale on ebay? - Page 1
Forum section: electronics / projects

author: mr ed
author_rank: Regular Contributor
timestamp: September 05, 2025, 11:25:56 am
content: Something fishy, same stolen pictures, same 7 days to ship time. I assume they will ship some worn out production unit they get cheap.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 05, 2025, 12:54:36 pm
content: or many same items sold under different vendors names, even feedbacks are shit ...it is an really annoying behaviour and Ebay does nothing, all photos should have some markers in them

author: Terry Bites
author_rank: Super Contributor
timestamp: September 06, 2025, 04:07:47 pm
content: Ebaysee no evil, hear no evil, speak total shit.Its just a bot now. Kill the bots.