hybridfree/eevblog-posts huggingface dataset:
what smd part is it - Page 1
Forum section: electronics / projects

author: rooky
author_rank: Contributor
timestamp: October 28, 2017, 05:40:27 pm
content: Hi expertsI need some help with a smd label.I have a SideWinder Mouse X8 where the charging is not working. blown fuse I did repair already. On the charging cradle connected with the PC there is a SOT-23 / SOT-323 part labled ADGV 2c which has the marking M1 on the PCB next to it.Does any one have an idea what part this is. NPN/pNP or MOSFET n-/p-Channel transistor???Thanks a lotbest regardsRooky

author: RES
author_rank: Regular Contributor
timestamp: October 29, 2017, 08:06:43 am
content: BC849C(W), NPN.http://www.s-manuals.com/smd/2cYou can test if the part is a transistor (two opposite diodes), check pins in datasheethttp://www.s-manuals.com/pdf/datasheet/b/c/bc846-bc849_general.pdf

author: rooky
author_rank: Contributor
timestamp: October 29, 2017, 09:54:02 am
content: Hi RESThanks ! I found the same datasheet,but I am confused since on the PCBnext to the part is M1 printed instead of Q1 whichis at other transistors e.g labeled t04Therefore I assume it might be a MOSFET but I have no experience with smd part labeling...Also I do not now if it is pnp or npn / n-/p-Channel.Since the circuit inside the mouse shows that 2 pins are connected as soon the external plug gets connected, I assume it bridges ground and pulls the gate of this M1 smd device to ground to provide 5v to the 3rd pin. Therefor I assume it is a p-channel. But I am not sure.....Measuring this smd part shows not the result expected for a npn/pnp.Multimeter always shows no connection...
What soldering iron at 50$ should I pick? - Page 1
Forum section: electronics / projects

author: samocamo123
author_rank: Newbie
timestamp: February 21, 2017, 11:13:41 pm
content: I was just wondering, what soldering iron at about 50$ should I pick? I don't do an insane amount of soldering so I want to keep the budget around 50$ I was looking at the TS100/Sainsmart Pro 32 because it is portable and heats up insanely fast (5-10 sec) but I was wondering if something like the YiHUA 936 or even the 8786D which has a hot air rework gun (which could be useful if I ever want to go more advanced into electronics repair and etc) would be better. What soldering iron do you think is the best at about 50$

author: james_s
author_rank: Super Contributor
timestamp: February 22, 2017, 01:21:49 am
content: Maybe look for a used Hakko 936? That's one of my favorite irons.There isn't much out there between the junky $20 Chinese clones and $100+ name brand soldering stations.

author: Kjelt
author_rank: Super Contributor
timestamp: February 22, 2017, 08:29:49 am
content: Buy a second hand older Weller/JBC/Hakko/......... and a new tip.

author: GreyWoolfe
author_rank: Unknown
timestamp: February 22, 2017, 08:49:55 pm
content: Be careful buying used Hakko 936s. Make sure they are complete and sold from the US. Also know that any new 936s are fake. Hakko discontinued them several years ago. The biggest problem with the fake 936s is that the tip to heating element fit isn't very tight which affects thermal performance. Also the fake tips are crap.

author: james_s
author_rank: Super Contributor
timestamp: February 22, 2017, 09:02:21 pm
content: Yes that's a good point, the Hakko 936 is probably the most faked soldering station in the world, and most(all?) of the fakes are pretty crappy. I guess imitation is the sincerest form of flattery. It's too bad they discontinued it.

author: saturation
author_rank: Super Contributor
timestamp: February 23, 2017, 12:47:07 am
content: For US buyer consider the $50 Japanese Hakko FX601-01, its the reimagined 936, search for old posts in the forum. Its rated at 100VAC but will work well in the USA at 120VAC; Japanese packaging. May be available from Amazon but definitely eBay. US version is 601-05 and is $80 and just packaged for US distribution.
What sort of potentiometer is this? - Page 1
Forum section: electronics / projects

author: lpc32
author_rank: Frequent Contributor
timestamp: December 02, 2014, 10:27:07 pm
content: Any idea what sort of slide potentiometer this is? There are 4 terminals on each end. It's part of an old boombox.

author: jlmoon
author_rank: Unknown
timestamp: December 02, 2014, 10:39:55 pm
content: dual channel pot with guard or shield node? Could be a volume, tone or balance

author: free_electron
author_rank: Super Contributor
timestamp: December 02, 2014, 11:07:36 pm
content: that extra pin is a tap for loudness. if you go over a certain setting they alter the bandpass curve.

author: lpc32
author_rank: Frequent Contributor
timestamp: December 02, 2014, 11:17:50 pm
content: Is there a name for this form factor?Is that 4th terminal a standard/common feature?I'm guessing "B" is the taper. Any idea what's the 4 letter code and the circled A?It appears to be Panasonic, based on this:http://www.ebay.com/itm/171200931961

author: miguelvp
author_rank: Super Contributor
timestamp: December 03, 2014, 02:21:14 am
content: I would think the B denotes that it's a linear pot.http://sound.westhost.com/pots.htm
What sort of stepper motor should I use for this? - Page 1
Forum section: electronics / projects

author: Ampera
author_rank: Super Contributor
timestamp: February 24, 2015, 07:29:04 pm
content: I wasn't sure if this belonged in beginner questions, or here so I picked one.I am working on a robot based off the RasPi2 and I want to have it basically be a car with plugs for attachments like arms, baskets, HIDs etc.. and I want to base the whole drive off one stepper motor. I am not sure what motor to use, and when I looked at newark I found a massive array of stepper motors that really just confused me.I am willing to do some searching if anyone can give me pointers or clues, but direct links to products would be nice.I basically need something relatively lightweight and can supply a decent amount of power (Has to carry maybe 5-8 pounds).Also if anyone has any ideas for lightweight or light cost batteries, that would help. I really don't want to say screw it and put a ton of D or C cells and have a cheap recharger.

author: Ampera
author_rank: Super Contributor
timestamp: February 24, 2015, 09:29:23 pm
content: I asked my dad (Who has a masters in engineering) if this is good.http://www.newark.com/sanyo-denki-sanmotion/sh1601-0440/stepper-motor/dp/34R8310My plan is to run the robot off a 24v lead-acid battery (Because they are cheap and they kinda work)

author: Siwastaja
author_rank: Super Contributor
timestamp: February 25, 2015, 12:12:47 am
content: Steppers are nice when you need to hold things and move them relavitely accurately and low to medium speed, but it's useless for traction purposes due to poor efficiency, low speed and poor torque at higher speeds. So steppers can be useful for rotating an arm, for example, but for traction, use brushed DC with a gearbox, those are extremely cheap and even easier to use from the microcontroller/computer than the steppers.Regarding the battery question.Lead acid is absolutely the worst if you want even remotely light-weight, it has the worst gravimetric energy density. And, the ones that do not self-destruct in one year when cycled cost more than the usual ones (and you need to get the right type). Recharceable off-the-shelf NiMH cells is a lot better option if you want to go that way, but for the last 10 years, people have usually used those Hobbyking style "lipo" packs (about 10x better energy density than the lead acid), which is an easy solution if you use off-the-shelf chargers and low-voltage cutoff devices available at those stores. Those solutions are easy and well-tested by the masses of RC hobbyists.
What symbol is this? - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: June 24, 2021, 01:03:11 am
content: Hi,at the risk of sounding dum, what is the symbol attached? I looked up countless lists of electronic symbols and couldn't find it. And in 20 years of electronics never seen it before.Two pictures attached , the symbol and the schematic containing it.It looks something shielded as it is grounded, maybe some type of connector or connection like maybe some like of shielded jumper/link?Thank you

author: bob91343
author_rank: Super Contributor
timestamp: June 24, 2021, 01:41:30 am
content: I do believe it's shielded or coaxial.

author: Miti
author_rank: Super Contributor
timestamp: June 24, 2021, 02:26:20 am
content: That’s a weird symbol. I don’t remember seeing it before.

author: tanveerriaz
author_rank: Contributor
timestamp: June 24, 2021, 03:13:33 am
content: it's look like a test point.

author: dmendesf
author_rank: Frequent Contributor
timestamp: June 24, 2021, 03:18:45 am
content: Maybe it's a feedthrough capacitor?

author: magic
author_rank: Super Contributor
timestamp: June 24, 2021, 05:04:52 am
content: Definitely looks like abstract goatseNSFW ofcMaybe that was the whole joke and it's just coax

author: phil from seattle
author_rank: Super Contributor
timestamp: June 24, 2021, 02:34:35 pm
content: Given that the "schematic" is just block diagrams and the outer ring goes to earth, it is definitely a coax with shield.

author: ricko_uk
author_rank: Super Contributor
timestamp: June 24, 2021, 07:02:27 pm
content: Thank you all!
What the ???!!! 920MHz Xbee interferes with op amp circuit - Page 1
Forum section: electronics / projects

author: Nite_Shift
author_rank: Newbie
timestamp: December 09, 2019, 03:33:19 am
content: Wondering if anyone has any thoughts on this..I have a simple non inverting amplifier circuit (LM7321, with a gain of 4.3 (R1=33K, R2=10 K)) running on my lab power supply. The non inverting input is fed with a voltage divider off the rails.When my battery powered 920MHz xbee transmits at 100mm distance, the op amp output dips up to 1V for the amount of time the xbee is transmitting.If the xbee is 1m away, the output dips by about 100mV. I have tried a couple of other op amps, same result!\Just to be clear, The rails and the non inverting input are clean, and the dip in voltage lasts the length of the transmission and is not noisy. Very strange. Attached screen shot of op amp output. transmitter is 100mm away, and BATTERY powered.Does anyone know what I can do here, short of changing to 2.4GHz?

author: DaJMasta
author_rank: Super Contributor
timestamp: December 09, 2019, 03:38:29 am
content: Take a look at your opamp's power rail. A low power transmitter typically gulps down current compared to normal operation when transmitting a packet, so it really could just be a bypassing issue. My guess is the PSU is not fast enough to respond to the output change and probably has low output capacitance.

author: exmadscientist
author_rank: Frequent Contributor
timestamp: December 09, 2019, 03:48:17 am
content: LM7321 appears to have bipolar inputs (though the datasheet does not say this explicitly... how lazy does a manufacturer have to be to not indicate the input type?), which are quite susceptible to RFI rectification. There are several app notes out there describing this effect and proper solutions to it, though I'm feeling too lazy to link them at the moment (guess that was contagious... that way you can blame National....). For a quick fix you can try substituting a FET input type and seeing if things get better.

author: OwO
author_rank: Super Contributor
timestamp: December 09, 2019, 06:28:32 am
content: Yes any RFI on any pin of the op-am can get rectified and show up as an offset. There are op-amps with specified EMI rejection (e.g. TP2311) to deal with this problem, but I recommend just designing your board to avoid any EMI getting in in the first place. At least one solid ground plane, striplines for all sensitive signals, filtering on off-board connections, etc.

author: FenTiger
author_rank: Regular Contributor
timestamp: December 09, 2019, 08:23:24 am
content: What's the bandwidth of your scope, and how are you connecting it to the power rail?If 920MHz was getting onto the rail, would it show up on the scope at all?What happens if you add a small decoupling cap directly across the op-amp power pins?
What to assume when a datasheet doesn't specify how to clean after soldering? - Page 1
Forum section: electronics / projects

author: oneil
author_rank: Newbie
timestamp: December 09, 2024, 10:20:41 pm
content: I'm getting a board manufactured that has a BMD-340-A-R (BLE module). The board house is asking me if it can be aqueous cleaned.I never gave a thought to whether or not it could be. The datasheet doesn't mention anything about cleaning after assembly. I've tried reaching out to the manufacturer, u-blox, to get a definitive answer one way or another. I also posted on their forum. No bites on either and it's been days.Looking at datasheets of other parts I frequently use, e.g. battery protection ICs from TI, battery chargers, etc. I don't see any recommendation on cleaning.In these cases, am I same to assume that aqueous cleaning is okay? Curious to hear what you think

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: December 10, 2024, 12:38:47 pm
content: Given the non-hermetic shield, that doesn't look like something that can be washed or cleaned at all. It might have a trimmer cap as well, so I'd say be safe and use a process that doesn't require cleaning.

author: oneil
author_rank: Newbie
timestamp: December 10, 2024, 03:17:22 pm
content: I will say that the shield is almost deliberately non-hermetic. There is plenty of clearance between the components and the metal shield over them. You can look through one side and see out the other. I took the shield off to inspect the components underneath: the nRF5240, some passives, and a crystal (that I tore the top of the package off of). See picture.
What to do on a desert island (in inland NSW) for 7 years? - Page 1
Forum section: electronics / projects

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2014, 12:49:25 am
content: This story definitely deserves a place here. Classic Australian story, almost Mad Max class.http://imgur.com/gallery/hRf2trVWas isolated from 1999 to 2006 with a 486. Built my own late 80s Operating System - by fiberbundleViahttps://news.ycombinator.com/item?id=8747053What an amazing tale! One that resonates for me since I had a very isolated childhood too, despite living in suburban Sydney. Nowhere near as 'colourful', thank goodness.Edit: Oops, this was meant to go in General Chat. Oh well, it kind of fits here too.

author: Falcon69
author_rank: Super Contributor
timestamp: December 15, 2014, 03:44:41 am
content: i agree, it fits here. this was a 7 year project. very interesting.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 15, 2014, 11:10:17 am
content: Cool!I have a few megs of old history with QBasic, myself. But that was an earlier time, and had the benefit of internet in the house and frequent library access.The last thing I was working on was (guess what) a raycaster: what you're seeing here is some walls on the right, and mirror blocks on the left:By this time I was even writing asm routines, which still sucked, but for how bad QB is, I was up over 30 FPS on a not-slacking machine. (Integer math is slow as it goes through functions, but woe be unto you if you start using floating point -- it steps through five or ten FAR CALLs in the process of performing one floating point operation, for all the load, manipulation, store and error checking I think.)I later studied the 8086 instruction set in depth, ported much of that program to pure asm, and got a bleeding 450 FPS on a 1.6GHz Duron.It's amusing because, a processor like that, the entirety of the program and data fits within cache, so the whole program runs inside the CPU chip itself, only ever needing to talk with peripherals and system memory for OS tasks and I/O (notably, copying the frame buffer to the display).Tim

author: Zero999
author_rank: Super Contributor
timestamp: December 15, 2014, 12:03:58 pm
content: What happens if you develop schizophrenia and can't work?Create your own operating system!http://www.templeos.org/I suppose I shouldn't laugh at this but it cracked me up when he said "God said it must be 640x480 16 colour VGA."
what to do with 2 high power devices I have aquired - Page 1
Forum section: electronics / projects

author: firehopper
author_rank: Frequent Contributor
timestamp: July 19, 2021, 06:22:15 pm
content: both are toshiba, one is a 75l6p43 3 phase bridge rectifier. the other seems to be a igbt device. I know what I want to do with the rectifier, no clue what to do with the other.

author: firehopper
author_rank: Frequent Contributor
timestamp: July 19, 2021, 06:23:42 pm
content: if I dont figure out what to do with the igbt, maybe I can send it to noopy so he can crack it open and take pictures.

author: antimatter503
author_rank: Contributor
timestamp: July 19, 2021, 06:25:28 pm
content: How about a solid state tesla coil (SSTC)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 19, 2021, 07:43:17 pm
content: Pretty ordinary, 600V 100A half bridge, mediocre speed (pretty fast for its day I suppose):https://pdf.searchdatasheet.com/datasheets-0/toshiba/MG100J2YS40.pdfYou're unlikely to use it at continuous capability (~10kW) without industrial power supply and application, but it would do fine in an offline power converter of a few kW (just running at reduced ratings, no sweat), or pulsed at a few 10s kW (like an SSTC).The downside to an SSTC is, because the switching speed is relatively low, the resonant frequency needs to be low, meaning the secondary needs thousands of turns of relatively fine wire. You'd probably want to set up a winding jig to make one, or buy one already made from eBay or whatever.Tim

author: firehopper
author_rank: Frequent Contributor
timestamp: July 19, 2021, 08:09:51 pm
content: Quote from: T3sl4co1l on July 19, 2021, 07:43:17 pmwell it was in a battey backup system with tons of gel cells in it. at least 24 batterys, 12v 10ah I do belive. there were more of the half bridge things in there. but couldnt get at them easily. including 2 huge transformers.

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 20, 2021, 01:57:36 am
content: How about a DIY induction heater of some sort?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 20, 2021, 05:04:13 am
content: The trouble with doing much of anything is, the semiconductors are a tiny cost of the overall build. If you had salvaged most of the thing, it's possible it could be repurposed into something other than what it was; but without those materials, you'll have to build or buy them specifically for whatever thing you do.Tim

author: firehopper
author_rank: Frequent Contributor
timestamp: July 22, 2021, 03:37:08 pm
content: well it was still at work. got some more bits, including one more power transistor, 2 different ones, a few capacitors, and what looks to be current sensors.

author: firehopper
author_rank: Frequent Contributor
timestamp: July 24, 2021, 12:27:41 pm
content: lets see I have2 - mg100j2ys40 toshiba1 - mg75j1zs40 toshiba1 - pk55gb80 sanrex1 - 75l6p43 toshiba2 - nnc-10ga Nana electronicsa big transformer/choke maybe.4 capcacitors of differing values/voltages. have plans for the 75l6p43, no idea what to do with the rest. got a huge heatsink everything was attached to as well.
What to do with a junk A3 Wacom PCB? - Page 1
Forum section: electronics / projects

author: dexters_lab
author_rank: Unknown
timestamp: December 14, 2015, 06:50:28 pm
content: i have a big A3 sized PCB from a Wacom Intuos graphic tablet here, the controller board got used for something else so it's a case of think up something interesting to do / make with it or bin it!Has many parallel tracks vertical on one side and horizontal on the other, i dont recall how they are connected / configured thoughany ideas?!

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 15, 2015, 06:07:26 am
content: It's just a huge array of inductors. For fun, try using one to build your own graphics tablet! For a really nice project, find a LED backlit LCD (CCFL will cause too much interference) of about the same size as the active area of the array, remove the metal backing of the LCD (replace with a sheet of white paper for use as the reflector), add a panel of glass over the front, and fit it over the array. Then either make a stylus (ferrite antenna and pressure sensor in a pen casing) or get a commercial active stylus.BTW, while most commercial tablets drive the pen and receive on the array, an easier DIY approach might actually be to drive the array and receive on the pen. Main disadvantage is higher power usage, which is not really an issue for a mains powered device.

author: dexters_lab
author_rank: Unknown
timestamp: December 15, 2015, 08:32:16 am
content: Quote from: NiHaoMike on December 15, 2015, 06:07:26 amooh, well maybe a bit of an effort, was thinking of something a bit simpler, and i do have a smaller Wacom anyway.funny though, this board had previously been hacked onto the back of an LCD!
What to do with an old Fetch TV box? - Page 1
Forum section: electronics / projects

author: numloxx
author_rank: Contributor
timestamp: May 15, 2015, 11:55:25 am
content: Hi all,Hopefully I'm asking this in the right forum. Sorry if i'm not.In 2011 I bought outright a Gen 1 iiNet Fetch TV box. Recently the hdd died, and because it's out of warranty I have to rent or purchase a new one from iiNet.What can I do with the old box? The model is YX-6936U and it's got a 1tb (dead) Hitachi HDD in it. It still works apart from the hard drive, but obviously doesn't boot up. Might put a blank hard drive in and see what it does, but I've been told that the existing drive is encrypted and cannot be accessed.Any suggestions would be appreciated

author: SeanB
author_rank: Super Contributor
timestamp: May 15, 2015, 04:27:08 pm
content: Dead how, as in smoke came out of it or the drive has unrecoverable errors. If you put a blank drive in it and do a factory reset ( you will lose all the account parameters most likely, so have them handy) it should just format the drive and act like new again.

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: May 16, 2015, 11:06:23 am
content: LET THE MAGIC SMOKE OUT!!!!

author: Fraser
author_rank: Super Contributor
timestamp: May 16, 2015, 12:25:27 pm
content: OT but in a similar vein.... I bought a SKY HD Satellite receiver/PVR many month ago for £2 from a charity shop. No remote but it still had the SKY viewing card installed !I am not a fan of SKY or their marketing pratices so I had great pleasure stripping the Samsung mad box down to its parts. I binned the case etc but will be keeping the PCB's for SMD desoldering practice and the Hard Disk is working fine. The HDD is what I am most pleased with. Its a slimline 3.5" 320GB Seagate SATA pipeline drive. Even though small by modern standards, the performance is great for video editingFull testing and checking the SMART reporting shows it to be in fine shape.The Power supply is still good and I gained lots of useful screws for future projectsNot bad for the price of a coffee in CostaAurora
What to do with Dell M109S projector parts? - Page 1
Forum section: electronics / projects

author: plazma
author_rank: Frequent Contributor
timestamp: January 14, 2013, 10:46:42 am
content: I bought 2 of these:http://www.ebay.co.uk/itm/Untested-Dell-M109S-LED-Micro-Projector-Contains-High-Power-RGB-LEDs-Optics-/110999180906Looks like nice parts inside. I'll try to fix one and one can be used for something else. RGB spotlight? Other ideas for parts?The connector looks like PDMI? Any sources for PDMI connectors?
What to do with unused transformers - Page 1
Forum section: electronics / projects

author: jtruc34
author_rank: Regular Contributor
timestamp: February 15, 2023, 01:48:49 pm
content: Following a bad design and a poor decision of ordering without thinking enough, I'm now in possession of two 100VA 12V toroidal transformers.Do I have any chance to resell them at a price that'll cover shipping at least, or could you see some project I could do with them?Thank you

author: shakalnokturn
author_rank: Super Contributor
timestamp: February 15, 2023, 02:04:52 pm
content: If the tores are open and not filled with resin and a mounting thread you could stack the transformers and wind a couple of turns of thick wire for a spot welder.

author: mariush
author_rank: Super Contributor
timestamp: February 15, 2023, 02:14:52 pm
content: Make a class AB audio amplifier, or even a class D amp.Make a soldering station - get a Hakko 936 clone circuit board and hand piece for 24v AC , connect your two transformers in series to get 24v AC and you have a soldering station.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 15, 2023, 02:44:07 pm
content: Connect the secondaries together to make yourself an isolation transformer, then plug one primary to the mains.The remaining primary will be a galvanic isolated mains, useful when a measurement requires to float the DUT.

author: Bud
author_rank: Super Contributor
timestamp: February 15, 2023, 02:54:39 pm
content: Connecting the primaries in series will make 2x 6V on the secondary side that can be used in parallel, individually or as 12V center tap.Edit: thinking a bit more, with two switches commutating the primaries and secondaries in series or parallel on each side, can produce 6V, 2x 6V, 12v, 2x12 or 24v AC. May be useful to make a bench power supply.
What to implement for gaining experience in control loops? - Page 1
Forum section: electronics / projects

author: atferrari
author_rank: Frequent Contributor
timestamp: May 24, 2015, 02:17:48 pm
content: I intend to gain hands-on experience in control loops (of the PID type). At this stage, op amps to be used.I am looking for suggestions (the easiest / simplest / cheapest / quickest) on two concrete points:1) a "plant" that I could implement on my bench.2) way of tracking ( eventually recording) set point - system output - error - time. If things go not too fast, I guess I could do it manually but not really sure.After reading a lot, starting with Bob Pease, I concluded that something related to temperature control or motor speed are the best candidates. Have read about a pendulum but sounds complex to start with so I discarded it already.Suggestions appreciated.

author: orion242
author_rank: Unknown
timestamp: May 24, 2015, 02:34:41 pm
content: Quote from: atferrari on May 24, 2015, 02:17:48 pmResistor with a bit more power than its rated with a thermocouple or thermistor strapped to it.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 24, 2015, 02:49:55 pm
content: Audio amplifier -- practical application, can be very fast (good for oscilloscope measurements, and potentially getting into more involved concerns like stray inductance and its effect on loops and stability).Switching suppliesFilters, frequency response -- it all goes on the Bode plot after alletc.Tim

author: dom0
author_rank: Super Contributor
timestamp: May 24, 2015, 03:15:49 pm
content: A large part of analog control loop design is relating bode plots to their real world effects and vice versa - deducing specific points of a bode plot from a measured real world phenomenon - the reason why many people stare at step responses and tweak things with them.

author: Kalvin
author_rank: Super Contributor
timestamp: May 24, 2015, 03:41:44 pm
content: Also a simulator, like freely available LTSpice, can be handy. You can build a PID controller and generate different stimulus (sine, step, pulse signals) with an ease, and put different loads (resistive, capacitive, inductive, combinations of R L C) and see how the control loop behaves. Simulators allow paramteric sweeping, which is a nice feature to study "how changing this parameter will affect loop stability or loop behaviour". Of course, building something is the ultimate breadboard where the theory meets practice.Ps. Simulator should be considered only as a fast calculator, not a substitute of intelligence. Simulator is a good example of a SISO device ie. s**t in - s**t out. So, if the simulation model is bad, the results will be bad - that is typically easy to detect. If the simulation model is good, the results are typically fine - and the user is happy. Worst yet, it the simulation model is wrong and you do not know that, you may still get results which look good until you build the circuit and face the reality. Simulators are nice to have, but one shouldn't trust them too much.
What to look for - DSUB shorting bar - Page 1
Forum section: electronics / projects

author: daqq
author_rank: Super Contributor
timestamp: February 19, 2016, 08:53:47 am
content: Hi guys,Some time ago I came across a DSUB connector that had a lot of pins connected in parallel (ground) using a shorting bar - a simple piece of sheet metal with solderable fingers that cut to length (to connect N pins) and was soldered into the cable positions.I can't find this kind of shorter anywhere. I'd love to use it, since I've got a lot of pins next to one another connected in parallel - this would save me a lot of time and effort.Do you know what to look for? Ideally, a farnell link :-)Thanks,David

author: Paul Price
author_rank: Super Contributor
timestamp: February 19, 2016, 10:37:00 pm
content: uhmm...have you tried wire?

author: ChristofferB
author_rank: Frequent Contributor
timestamp: February 20, 2016, 12:48:29 pm
content: Not sure it's something that's buy-able - solid core wire would be pretty much as good, I agree.Else get some thin sheet copper and cut out the bar yourself - or even single sided copper clad pcb!--Christoffer

author: Ian.M
author_rank: Super Contributor
timestamp: February 20, 2016, 12:54:22 pm
content: It may even have been the bar that insertable contacts for a mating connector came on.

author: daqq
author_rank: Super Contributor
timestamp: February 20, 2016, 01:20:55 pm
content: Thanks guys,QuoteThat's what we're using now. A pre-made fingered bar you just solder in. A wire you need to bend*, it would be generally more fiddly and looks worse (personal opinion). Also, if you have the whole bottom side of a 25 pin DSUB connector connected to one ground it just won't look nice and will be annoying to solder.* - or just solder it above the pins in parallel which looks bad and increases the height of the connection.QuoteThat's even fiddlier than wire.I was hoping to use the simplest route. I guess I'll stick with wire then.QuotePossibly, I don't remember it that well.
What to look out for in a wide output DC - DC converter? - Page 1
Forum section: electronics / projects

author: tmadness
author_rank: Regular Contributor
timestamp: October 13, 2021, 10:17:55 pm
content: My switching power supplies fundamentals are a bit rusty. if I wanted to design a dc dc converter with constant input voltage but variable output voltage, what should i be looking out for in a converter/controller?a few parameters that come to mind:Min switch on time, determines how low the output voltage can go.what about switching characteristics? PFM vs PSM vs PWM? this should not be an issue... I think.feedback mechanism? again should not matter.what else? inductor choice? angle of the sun and moon?

author: moffy
author_rank: Super Contributor
timestamp: October 14, 2021, 12:28:25 am
content: If going for PWM(I am talking about a transformer with secondary and rectifier) to get the variable output voltage vs duty cycle the output choke has to be conducting continuously. This means either large choke or a large static load, otherwise for low conduction of the output choke you are going to get a voltage leaning towards the peak pulse voltage. Flyback can be a little easier as the energy transfered is LI*I/2 for each pulse. You can adjust the frequency of the pulses to match the load/voltage, but ripple can sometimes be an issue.
What to look out for when adding a DAC to a DC/DC converter feedback ? - Page 1
Forum section: electronics / projects

author: chipeater
author_rank: Contributor
timestamp: January 13, 2023, 04:36:21 pm
content: Hello,I would like to add a DAC to the feedback of a DC/DC converter to adjust its output voltage via a microcontroller.I have already tried this type of setup with an LM3150 and a LTC2601 but I had a lot of problems (the DCDC did not start every time or stopped for no apparent reason, I had no problem without the DAC).I would like to renew the experience with a TPS62933 for example.The idea is to create an adjustable power supply from 3V to 15V from 24V.Are there any features to look at on the DAC or the DC/DC to implement this configuration ?Do you have a DAC part to recommend for this ?At first, I was inspired by this :https://www.fischl.de/dcdccontrol/Thank you very much

author: Terry Bites
author_rank: Super Contributor
timestamp: January 14, 2023, 04:38:58 pm
content: Have a read:www.analog.com/en/technical-articles/a-3step-approach-for-designing-a-variable-output-buck-regulator.html
What to make with +/-76V transformer ? - Page 1
Forum section: electronics / projects

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 26, 2019, 02:57:50 pm
content: I salvaged a Kenwood audio-video surround receiver. And it powered up and looks fine inside. So I have a big transformer with +/-12V control rails, +/-76V with bridge rec.'s rated for 2.8A unheat-sinked like these, 6A when heatsinked. There's also relays controlled from a STBY trans, for the +/-76V rails.So that whole area of the board can be sawed off and be a great and safe supply , what should I make in the way of lab power supplies or something useful like that?I also have a rotary encoder, another really nice circular dial, a nice LED/display.And I found the whole schematic and it's great. So I have all the details on the chips and controlling the LED display for other stuff I guess., And everythjing else in there.https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=2ahUKEwjhyaa8m4fjAhUiB50JHR12D8AQFjADegQIAhAC&url=https%3A%2F%2Fwww.vintageshifi.com%2Frepertoire-pdf%2Fpdf%2Ftelecharge.php%3Fpdf%3DKenwood-KRFV-4070-Service-Manual.pdf&usg=AOvVaw1xzC74qMbSssL0f9VuV2r2PSU is on page 13There's 4 relay's total, and also a +/-46V winding. I haven't found the current rating. I found the stereo schematic from looking up the transformer 1st.I could load test it, but so far it's too big for my imagination and needs.
What to shield when making a short VGA cable - Page 1
Forum section: electronics / projects

author: T0mn0mn0m
author_rank: Newbie
timestamp: April 13, 2014, 09:03:33 am
content: I'm working on a project that requires a short run of a VGA signal in fairly close proximity to some noisy ish components and space is very limitied.I'm using the red, green, blue, H-sync, V-sync, SDA and SCL wires. the cable is about 15 cm long and a few cm away from a small DC-DC converter. I tried just using hookup cable, but found that at low resolutions the image was vissible scanning, and higher resolutions did not work at all. I know I need to shield the RGB cables, and I'm fairly sure the SDA and SCL cables (carrying screen resolution info) are ok unshielded, but I'm unsure about the H-sync and V-sync wires. And as this is a direct connection I'd like to do it with minimal trial and error.Thanks for any insight.

author: SeanB
author_rank: Super Contributor
timestamp: April 13, 2014, 09:45:29 am
content: Just do them all in an overall shield, and have the RGB and HV sync in coaxial cables inside the overall shield. The I2C can just be a pair inside the overall shield. Simple to do by using some existing VGA monitor cabling, you probably either buy a complete cable and cut it and put connectors or look for a dead monitor and strip the cable out of it.
what to use 555 timer - Page 1
Forum section: electronics / projects

author: kjn4685
author_rank: Regular Contributor
timestamp: June 24, 2015, 02:57:33 am
content: I have started a new project using 555 timers to control a dc motor. I have being working on a remote control window shades. I have a diffcult time getting to the shades because I am handicap. I have tried everything that I can think of. I would appreciate any help you can give me. I would put a schematic on the forum if I had one ,but I have tried every combinations that I know about. As far as the remote I have a working circuit. Thank you in advance for your help.If you guys need more nformation I will try to come up with it.Lou

author: void_error
author_rank: Frequent Contributor
timestamp: June 24, 2015, 08:10:23 am
content: It would help a lot if you showed a schematic...There might be a better or simpler solution than the 555 timers.

author: Kalvin
author_rank: Super Contributor
timestamp: June 24, 2015, 10:32:07 am
content: There are some Arduino projects floating in the internet which might be of good starting point. Maybe there are even ready made modules which would react to the IR remote button presses and activate the corresponding receiver module output line. For example, if you keep the remote button "1" pressed the corresponding receiver output pin "1" will be held active as long you keep the button pressed. When you release the button, the output "1" will go off. Similarily, for example, if you keep the button "2" pressed the corresponding receiver output "2" will be active as long you keep the button "2" pressed. And when you release the button, the receiver output "2" will be turned off. Thus, you can control the DC motor activity and direction using the IR remote.Here is a simple project using a programmable Simerec SIS-2 IR decoder:http://www.popsci.com/diy/article/2008-10/make-master-remotehttp://simerec.com/SIS-2.pdfThere is also a Simerec SIS-7 part available with 7 outputs:http://simerec.com/SIS-7.pdf

author: kjn4685
author_rank: Regular Contributor
timestamp: June 24, 2015, 05:17:48 pm
content: Hey thanks for all your information. I appreciate everything you guys have done. I will try to use the sis2 chip.Lou

author: Kalvin
author_rank: Super Contributor
timestamp: June 24, 2015, 05:50:41 pm
content: Here is one Youtube video showing the SIS-2 chip in action.1. Programming (learning) the two IR remote buttons.2. Activating the output as long the button being held.3. Discrete button mode ie. toggling the output at each button press.Looks pretty good and simple.
Transformer with 2 windings of 12V at 33.3A. What to build? - Page 1
Forum section: electronics / projects

author: peteb2
author_rank: Regular Contributor
timestamp: April 30, 2019, 03:39:16 am
content: I just scored one in an auction of 'unused' new parts. The thing is fairly big at around 170Hx152Wx85D andheavy. Spec: 400VA Pri 2 x 115V, sec 2 x 12V@33.3A (or series 24V).30 odd Amps is fairly large for general electronics. I don't need a welder and i have enough other rubbish to be put to use as boat anchors. I'm thinking maybe an old school wet-cell battery charger with BIG bridge rectifiers, switchable for 12V or 24V that'll get near the right voltage...Appreciate your ideas.

author: German_EE
author_rank: Super Contributor
timestamp: May 01, 2019, 04:37:16 pm
content: Find a local radio amateur and make a new friendI had a transformer like that once, in fact, thinking about it, it was bigger as the rating was 13V @ 100A. I built a shack power supply into a two drawer filing cabinet with the transformer in the bottom and the electronics in the top. One supply ran all of the equipment in the room.
What to use for stacking ic sockets ? - Page 1
Forum section: electronics / projects

author: Wawavoun
author_rank: Regular Contributor
timestamp: July 28, 2025, 06:44:33 pm
content: Hi All,I want to connect a pcb into a ic socket and then install a ic on this pcb exactly on top of this stack. I hope I am clear...Image like a wire wrap ic socket welded through a pcb (top one) and then the long pins inserted into another base ic socket (on the bottom pcb).I know "elevated" ic supports but I cant find them in stock somewhere on line. Wire wrap supports have square pins, I am not sure they can be inserted reliably into ic socket.I search a suitable solution for dip 14, 16 and 24 (7.62 mm).Nothing is welded at this time so the basement could be something different that standard ic socket (like sip supports etc...). Usually I use machined ic supports.Of course weld everything together is not an option...Thanks for any advice.Philippeps : I have search (may be bad ?) the forum but not found a reply.

author: Benta
author_rank: Super Contributor
timestamp: July 28, 2025, 07:42:34 pm
content: https://precidip.com/Most distis carry them.

author: westfw
author_rank: Super Contributor
timestamp: July 29, 2025, 08:14:07 am
content: Like this?That's a standard "machine pin" socket, with holes in the "thin" PCB big enough so that the fat part of the socket goes through the board, leaving "full length" TH pins that will plug into a PCB or protoboard.

author: Wawavoun
author_rank: Regular Contributor
timestamp: July 30, 2025, 06:41:22 pm
content: Its a good idea.Will look at that closely.Thanks.Philippe
What type of 4-digit digital LED display module is this? - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: October 05, 2024, 02:32:37 am
content: Hallo everyoneI found an interesting electronic tool on the Internet, please watch the videoI was lucky enough to find its schematic diagram, but when I read the circuit schematic diagram, I found that U7 is a display module, but it does not have a standard specific chip model.It looks like a 4-digit digital tube integrated module. I have never seen such a module.If anyone knows it please tell me, thanks

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 05, 2024, 03:02:50 am
content: Your title says 8 digit but your question is about 4 digit ?You may want to edit the title.4 Digit LED modules are quite common in Asia, this link shows many choices for '4 places' from 0.26" to 0.8" with 0.56" the most common,https://www.lcsc.com/products/LED-Segment-Displays_532.html

author: daisizhou
author_rank: Super Contributor
timestamp: October 05, 2024, 03:47:11 am
content: Thanks. I fixed the error.Please see the picture, this is 4 LED display modules that can display 8-bit digital tubes.But in the schematic diagram, please see U7, its pin definition is different from the common digital tube.I don't know why this isAnd I didn't find any LED module in the schematic diagram. It seems that U7 is an interface or display module integration, and U7 does not show the specific model.

author: floobydust
author_rank: Super Contributor
timestamp: October 05, 2024, 04:38:33 am
content: This is the closest I could find, but no part number. "Youngsun"Or Lite-OnLTC-4727same pinout

author: daisizhou
author_rank: Super Contributor
timestamp: October 05, 2024, 05:05:23 am
content: Thanks .It really looks like
What Type of Binding Post Is This - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: January 10, 2024, 02:50:25 am
content: In connection with another thread regarding replacing an encoder switch in an adjustable power supply, I also need some replacement binding posts (see attached), but I've looked all over and can't find similar ones (most have male threads).The plastic external plastic piece is (all measurements in mm): 12 (diameter) and 15 (length). The metal part that goes through the panel is: 8 (diameter) and 10 (length).As the photos describe, the screw goes through a hole in the PCB (which makes the electrical connection), and into the end of the metal part of the binding post. The metal part goes through the front panel, and then the plastic screws front the front (the terminal color is painted on the front panel, not the plastic binding post).All the ones I've found online have a long screw. I can rework this into the existing design, but I can't find the correct diameter to fit through the panel (I'd be against drilling, but maybe this is an option).Does anyone have a good resource for binding posts?

author: PCB.Wiz
author_rank: Super Contributor
timestamp: January 10, 2024, 05:50:28 am
content: Google finds this spring loaded posthttps://www.farnell.com/datasheets/2787592.pdfone model shows a M3 tapped rear face, tho maybe shorter than your example ?. (the rest are the more common 4mm nuts )
What type of connector is this? - Page 1
Forum section: electronics / projects

author: graffitici
author_rank: Newbie
timestamp: July 14, 2014, 04:42:32 am
content: Hi all,I'm trying to build a PCB that can interface with the SeeedStudio Grove system. Essentially, I need a connector that looks exactly like this:http://www.seeedstudio.com/depot/Grove-Universal-4-pin-connector-p-789.htmlThe one they are selling is out of stock (and is a bit overpriced). Does anyone know what type of connector that is?There is a discussion in the comments about the "TE Connectivity 1735446-4", but apparently it doesn't fit?Thanks!

author: Psi
author_rank: Super Contributor
timestamp: July 14, 2014, 04:59:49 am
content: For people that cant be bothered clicking the link and zooming in..

author: miguelvp
author_rank: Super Contributor
timestamp: July 14, 2014, 05:13:06 am
content: doing a simple google of the sku: ACC39145Oreturned hits.http://www.epictinker.com/Grove-Universal-4-Pin-Connector-p/acc39145o.htmIs one of them in stock at $1 for 10 of them.QuoteThere are others as well, this was the first hit.Edit: the original listing is $0.90 for 10 of them so 9 cents per connector, I wouldn't call that overpriced

author: graffitici
author_rank: Newbie
timestamp: July 14, 2014, 06:09:35 pm
content: Thank you both! I didn't realize the original listing was for 10 units. That's indeed a very good price, if only they could keep them stocked!..

author: TheBorg
author_rank: Frequent Contributor
timestamp: July 15, 2014, 02:16:06 am
content: FWIW looks like a 2mm JST connector

author: Mr.B
author_rank: Unknown
timestamp: July 15, 2014, 04:20:27 am
content: TheBorg is correct.It is a 2mm JST.I have purchased them from Seeed before.They are a lot cheaper from Seeed than Mouser/Digikey.Not being in stock makes it a bit difficult.

author: Richard Crowley
author_rank: Super Contributor
timestamp: July 15, 2014, 05:19:07 am
content: As it appears to be a standard JST connector, there seem to be many alternate sources.Since graffitici has not revealed a location, it would seem pointless to try to recommend any particular sources.

author: Monkeh
author_rank: Super Contributor
timestamp: July 15, 2014, 07:29:29 pm
content: If it's a JST part, which series is it?
What type of DC-DC converter is this? - Page 1
Forum section: electronics / projects

author: Chupacabras
author_rank: Regular Contributor
timestamp: September 02, 2015, 10:40:23 pm
content: Hi,I am not able to figure out what type of DC-Dc converter is used here:http://www.ebay.com/itm/0-9V-5V-to-5V-DC-DC-Booster-Module-USB-Mobile-Step-up-Power-Supply-Module-BY-/191462466194?hash=item2c940d6292http://www.ebay.com/itm/0-9V-5V-to-5V-DC-DC-Booster-Module-USB-Mobile-Step-up-Power-Supply-Module-2014-/201110338593?hash=item2ed31c3c21http://www.ebay.com/itm/Mini-PFM-Control-DC-DC-USB-0-9V-5V-to-5V-dc-Boost-Step-up-Power-Supply-Module-/191187457756?hash=item2c83a916dcebay is full of such modules but nowhere is mentioned type.I also searched digikey and did not find such IC.What could it be?

author: tree
author_rank: Regular Contributor
timestamp: September 02, 2015, 11:00:54 pm
content: It's a boost converter.Based on the top markings it could be the KB2301.

author: Chupacabras
author_rank: Regular Contributor
timestamp: September 03, 2015, 05:34:53 am
content: I know it is boost (step-up) converter.But I was not able to find any converter in SOT-89 package and 0.8V/0.9V minimal input voltage, and 600mA maximum output current.Thanks for datasheet.
What type of filter should I use ?   - Page 1
Forum section: electronics / projects

author: Sharp
author_rank: Contributor
timestamp: October 04, 2021, 10:44:56 am
content: Hi guysI need an advice to suppress my 12V charting noise on my motor bike. I’m not at all experienced in filter design.I’m working on a project where the charting noise limit needs to be suppressed to maximum 200 mV PP.As you can see on the pictures the MC has an extreme noise level (Chanel 1 - the yellow one). I have done a preliminary test with a basic 2nd order passive low pass filter (Chanel 2 - the blue one) and as you can see it is a bad approach.What will you recommend my approach should be - A Murata fixed filter or design one like the Butterworth, Bessel or …I hope one of you experienced guys can helpBrSharp