hybridfree/eevblog-posts huggingface dataset:
Diodes in 4013 D–Type Flip–Flop Circuit? - Page 1
Forum section: electronics / projects

author: Chris56000
author_rank: Frequent Contributor
timestamp: March 30, 2024, 06:39:01 pm
content: Hi!Just a quickie one!Can anyone point me in the direction of a good logic reference book that explains the use of diodes with a 4013 D–Type Flip–Flop please?I have an old Intracept Electronics N7118 Colour TV Pattern Generator which has one–half of a '4013 clocked by a 4.43361875 MHz CMOS oscillator, the Q output goes to pin 2 (enable) of a '4520 decade counter (pin 1 (CLK) is earthed – I understand the '4520 will count on the positive transitions of the "enable" pin when connected this way) – what is puzzling me is that there is a diode connected between "Q" (pin 1) of the '4013 and "Reset" on pin 4, with the anode connected to pin 4 and the cathode to the "Q" output pin 1.Part of the reason why it doesn't make sense is because the diode anode is connected to "reset" pin 4 and cathode to the '4013 "Q" output pin 1, when I would expect the diode to be the other way round, with anode to pin 1 and cathode to "reset" pin 4!I don't have the maker's original schematic for this four decades–old piece of gear by the way – I'm having to draw it out myself!(This piece of gear was originally supplied in d.i.y. kit form to build yourself and nobody has the original plans, and I am given to understand from a Vintage Radio Forum Member that no circuit description was provided!)Chris Williams

author: Kim Christensen
author_rank: Super Contributor
timestamp: March 30, 2024, 07:34:33 pm
content: Quote from: Chris56000 on March 30, 2024, 06:39:01 pmIf the anode was connected to pin 1 (Q output) and cathode to "reset" pin 4 (Active high), when Q goes high, it would reset the flipflop immediately making Q go low again.ie: Q output would only go high for the duration of the propagation delay between pin 4 (reset/clr) and Q.We'd really have to see a full schematic to figure out what the purpose of the diode is.

author: Chris56000
author_rank: Frequent Contributor
timestamp: March 30, 2024, 07:37:50 pm
content: . . .I am continuing with drawing it out! There are two other diodes connected to pin 4 of this '4013, one goes to pin 11 (Q1) of the '4520B decade counter section that follows on from the '4013, and I've not worked out where the third diode goes to yet – all three of these diodes have their anodes connected to pin 4 with a pull–up resistor to +Vdd, so I know I have a three–input diode "wired–AND" gate with the "reset" pin 4 connected to the gate "AND" output!Chris Williams
DIP-8 Adapter/Prototyping boards - Page 1
Forum section: electronics / projects

author: dardosordi
author_rank: Regular Contributor
timestamp: January 28, 2018, 03:39:46 pm
content: That is correct, its an adapter for DIP-8 packages so I can SMD solder those while prototyping.Why? Well, I have many DIP-8 op-amps, don't like doing through hole boards (specially drilling) and I find SMD packages too damn small!So with this I can SMD solder (way more fun) DIP packages (way more easy).https://github.com/dardosordi/board-adapters

author: Benta
author_rank: Super Contributor
timestamp: January 28, 2018, 03:50:23 pm
content: Why not just "gull-wing" the DIP-8 (or the socket)?

author: dardosordi
author_rank: Regular Contributor
timestamp: January 28, 2018, 03:56:38 pm
content: This gives me a nice big pad next to each pin for prototyping.I made a batch of this and started using it for prototyping and I found myself enjoying it, so I'm sharing it because someone might also like it.

author: Ian.M
author_rank: Super Contributor
timestamp: January 28, 2018, 04:05:35 pm
content: It would be a lot simpler to just use a scrap of stripboard, copper side up, and a turned pin socket with its pins cut down to about half the strip board thickness.
DIP chip footprint vs DIP socket footprint. PCB making problem ... - Page 1
Forum section: electronics / projects

author: redben
author_rank: Contributor
timestamp: November 02, 2014, 12:58:48 pm
content: Hi, I have a simple question:Does socket for DIP package have the same mechanical properties as the chip itself ??I have sockets lying around that I don't have the data sheet and I want to use them in my design.If I use the standard DIP footprint of my chip, will the socket fit in that footprint ?And my socket has rigid leadsI could print out on paper to try, but if someone has any infos it would be very very helpful.Sorry for the english mistakes ...

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 02, 2014, 02:39:10 pm
content: Quote from: redben on November 02, 2014, 12:58:48 pmIf by properties you mean distances, yes, it should. You have Augat machined sockets?Or longer leads? Then it's a wire-wrap socket. You can still solder to them, just clip off the extra length.But are you making your own PCB? Then you don't have plated-through holes, so only use the bottom for connections, otherwise you have to solder on both sides of the board.

author: westfw
author_rank: Super Contributor
timestamp: November 03, 2014, 03:01:31 am
content: A DIP socket extends slightly beyond the holes, while a DIP package fits fully inside the hole pattern (except sometimes lengthwise.) This shouldn't matter for most PCB designs, but it is possible to design a PCB for chips that won't work with sockets.In the other direction, I've seen people put crystals and other components underneath a chip, where the sockets they are using happen to have empty space. So you can also design a PCB that works with sockets, but not without.

author: sleemanj
author_rank: Super Contributor
timestamp: November 03, 2014, 03:58:31 am
content: Measure twice, make PCB once.A set of digital calipers is very useful for the PCB designer to have on their desk, 10 seconds and you can accurately measure the thing to make sure.

author: redben
author_rank: Contributor
timestamp: November 05, 2014, 03:39:41 pm
content: Thanks for all the answers, That helped me figure it out.I finally made the effort to print it first on paper to make sure everything fits correctly enough.After some trouble to print it 1:1 My conclusion is :- it might be slightly too wide, but it still fit (I am talking 1/10 of a millimeter or there about).Nothing to worry about.
DIP SMT package - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 23, 2019, 11:38:33 pm
content: Using the LOC112Shttps://www.digikey.ca/product-detail/en/ixys-integrated-circuits-division/LOC112S/LOC112S-ND/654965It is basically a DIP8 with the leads splayed out and clipped.Here's my question, given the large size and weight of the chip, will the tiny SMT pads recommended have enough surface tension force to pull the package straight at reflow?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 24, 2019, 07:43:33 am
content: Parts about 1206 and larger, the package weight tends to dominate over surface tension.Basically, place it right the first time.Tim
DIP socket moss - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 31, 2019, 12:11:05 am
content: What could this be? This weird growth on just the one pin of a socket... The PCB is for a disk drive for a Commodore 64. Indoor stuff. The board looks fine. Just the ONE pin on the ONE socketed 74LS ... Is it a tardigrade? Or a new kind of mushroom?

author: amyk
author_rank: Super Contributor
timestamp: December 31, 2019, 12:56:39 am
content: Looks like dried battery electrolyte - maybe from a previous minor leak?

author: Cerebus
author_rank: Super Contributor
timestamp: December 31, 2019, 01:35:37 am
content: Tin whiskers? Certainly looks like them, and electro tin plate isn't uncommon on older sockets.

author: ChristofferB
author_rank: Frequent Contributor
timestamp: January 02, 2020, 03:06:24 pm
content: I don't think it's electrolyte leakage. The socket surface below looks shiny, and since there is almost certainly copper and/or nickel present, corrosion damage would have a green/blue tint.Quote from: Cerebus on December 31, 2019, 01:35:37 amI agree, maybe it's not tin whiskers from the socket, but from whatever DIP IC that was in it.
Need help! DIP28S to regular DIP28...? - Page 1
Forum section: electronics / projects

author: WyverntekGameRepairs
author_rank: Regular Contributor
timestamp: June 12, 2020, 02:17:36 pm
content: I ran into a problem while rebuilding a clock circuit that uses a lm8560 alarm clock chip: The pins are too close together for breadboard or perfboard use. I tried looking for socket adapters but I can’t seem to find anything. Is there any way to accommodate the DIPS into something meant to accommodate regular DIP pin spacing?
Direct drive controller for linear motor - Page 1
Forum section: electronics / projects

author: cmcraeslo
author_rank: Regular Contributor
timestamp: June 29, 2020, 06:34:24 am
content: Hey all.I have linear motor that i'd like to drive as an actuator (basically just on/off). I'm looking for the best and simplest way to actuate it fully in and fully out. Motor is capable of 2kW and I'll be running it at 48V. It needs to be as fast as possible and with maxium torque possible. Travel is only 25mm. No slow stops or starts. It will stop mechanically. Ideally, i'm looking for a solution that has all the logics & sensorless readings inside the chip, so only thing i'd wire up are the mosfets that will be driving the motor (+ other required stuff of course). I'd like to avoid china's 15usd modules.Thanks in advance.

author: Siwastaja
author_rank: Super Contributor
timestamp: June 29, 2020, 06:39:32 am
content: Is it an actual linear motor or a traditional motor integrated with a lead screw or similar? Motor type? Induction? Permanent magnet AC / BLDC? Brushed DC? Without any specs about the motor, it's hard to say anything.

author: cmcraeslo
author_rank: Regular Contributor
timestamp: June 29, 2020, 06:45:20 am
content: It's an actual linear motor. Coils are in the outside part and magnets in the middle.
Direct imaging of solder mask with UV printers - Page 1
Forum section: electronics / projects

author: cjb2051
author_rank: Newbie
timestamp: April 21, 2021, 08:23:55 am
content: Hi folks,I oversee a prototyping lab for fab/assm of PCBs and I’m exploring ideas to simplify the process of applying the solder mask treatment. Mostly I’m trying to remove the need of practice/experience from this process in a prototype setting so users can produce a precision solder mask without the headaches that are encountered with the manual application methods and inexperienced hands. Along these lines, directly printing/imaging the solder mask layer onto the board is attractive. There are some companies (Limata, Orbotech) that appear to offer this specific capability but it’s way beyond my budget.I’m wondering if anyone has tried (or maybe can tell me why its not suitable) to directly image the solder mask layer onto a PCB with a more generic UV printer. I realize these printers are also not cheap (particularly the Epson/HP brands). But there are some Chinese brand UV printers (Wer, Wayprinter, Funsun) that are within my budget of ~$3-4k and they’re happy to provide test samples. The stated printing resolution should be better than 1 mil and they claim the ink will adhere to copper and fiberglass. Board registration is a potential sticking point but I don’t feel this is insurmountable with a well designed board fixture.Is there any reason to believe these UV printed inks would not function as a suitable solder mask?

author: Berni
author_rank: Super Contributor
timestamp: April 21, 2021, 08:47:21 am
content: Make sure these UV inks can stand up to soldering temperatures. They might make a lot of awful smoke in a reflow oven, or melt off the tracks when a soldering iron is applied to a pad.But soldermask is not that important for prototype boards anyway as pretty much all common component packages solder just fine without a mask. Only exception might be advanced packages like BGAs and similar
Direct Logic 05 D0-05DR connection to pc. - Page 1
Forum section: electronics / projects

author: avitsur
author_rank: Contributor
timestamp: June 17, 2025, 11:21:02 am
content: I have this old Direct logic 05 D0-05DR controller. it's connection to the pc is via com port. is there a way to connect it to a usb port, and if so, how? I have the controller's software.

author: bill_c
author_rank: Regular Contributor
timestamp: June 17, 2025, 11:49:20 am
content: You need a USB to serial adapter, they even suggest or sell a specific one known to work although many others should work. Visithttps://www.automationdirect.com/they have the documentation you need.Some of the stuff they sell doesn't survive long term 24//7 use like small inverters, HMI, analog cards, etc.
Direction and proximity detection - Page 1
Forum section: electronics / projects

author: Greg J
author_rank: Regular Contributor
timestamp: May 18, 2021, 03:36:37 pm
content: Fine folk of EEVBlog forum,I got a little IoT device that I want to enhance - and it would be beneficial for it to know where the other boards are in relation to any one of them.Only a rough estimate of distance is required.The direction, however, is more important. I have thought about having a couple of traces on the PCB around the board's perimeter - to detect where a low-frequency signal is coming from - but I'm sure there are more civilised ways.Each device would know what direction other devices are and if they are close/medium/far. About 10/20m is all I need. The aim is basically to establish a poor man's mesh map in the garden. It is for another device to know where it is roughly in the 2D plane to others.With the devices on the market, such as drones being able to fly around in swarms, mobile devices knowing where things are (Apple has its U1 chip for that) - I'm sure there must be something reasonably off-the-shelf that would allow me to do that.Any ideas?Thanks

author: penfold
author_rank: Frequent Contributor
timestamp: May 18, 2021, 03:49:24 pm
content: There are some near-field/RFID type sensors that can triangulate distance, I think one of the applications was for tracking players on a sports field. I forget the exact details, though I think it was relying on time-of-flight, so could be a little awkward to implement. Maybe worth a look nonetheless.

author: Greg J
author_rank: Regular Contributor
timestamp: May 20, 2021, 09:10:19 am
content: Just to add to this question.These devices are not going to be have to actively map anything in real time - etc.Imagine a field, and you throw couple of these devices around - let them figure out positioning - and then they can remain there for days without anything moving.I'm trying to figure out if there's a way to do it, without having to dedicate 10 chips to that task - but rather with a simple design that could solve this cheaply and roughly.

author: Terry Bites
author_rank: Super Contributor
timestamp: May 20, 2021, 01:39:55 pm
content: I used a Texas part for just this. FDC1004https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjuiZuLr9jwAhXJDuwKHXokDF8QFjADegQIAxAD&url=https%3A%2F%2Fwww.ti.com%2Fcn%2Flit%2Fpdf%2Fsnoa927&usg=AOvVaw3ARm_516CI4iGz1PoGfvmvseehttps://www.analog.com/en/analog-dialogue/articles/capacitance-sensors-for-human-interfaces-to-electronics.htmltoo

author: Greg J
author_rank: Regular Contributor
timestamp: May 20, 2021, 03:49:41 pm
content: Quote from: Terry Bites on May 20, 2021, 01:39:55 pmI need higher distance then just a meter or so, and the devices need to talk to each other - so this won't do what I want - sadly. Unless I missed something.
Directional AC Current sensor with arduino? - Page 1
Forum section: electronics / projects

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: March 02, 2015, 06:16:32 pm
content: I need to find a way to sense AC current flow. I need to measure not only current, but the direction. IE +5A or -5A. It is for a grid tie setup, and I need to keep the meter from running backwards because we have been asked to unplug them. Anyone got any ideas?

author: Seekonk
author_rank: Super Contributor
timestamp: March 02, 2015, 06:22:05 pm
content: ACS712

author: mtdoc
author_rank: Super Contributor
timestamp: March 02, 2015, 06:22:11 pm
content: Current transformerHere's one example using with an Arduino.I'm sure there are many others around.

author: dannyf
author_rank: Super Contributor
timestamp: March 02, 2015, 06:23:36 pm
content: There are bi-directional current sense amplifiers.Otherwise, just wire two in with their output in parallel.

author: mtdoc
author_rank: Super Contributor
timestamp: March 02, 2015, 06:28:19 pm
content: Quote from: Seekonk on March 02, 2015, 06:22:05 pmI believe if there is only the need to measure AC (no DC) current, you're better off using a CT than a Hall effect sensor which are more prone to drift, etc.
Dirt cheap common Vref for 12bit ADC? - Page 1
Forum section: electronics / projects

author: MT
author_rank: Super Contributor
timestamp: August 02, 2018, 07:52:12 am
content: Which is the most common and dirt cheapest +2.5V and +3.6V reference? It's for STM32F4xxx obstinate 12bit ADC.The ADC is to calibrate AC signals. Yes i know, but TL431C would do 8bits for a narrow temp range so i ponder ifATL431B if temp 20degC +/-3deg C would cut 10bits. 100units for 0.318USD each from usual suspects.(ATL431B improved TL431).Perhaps i should stop fooling my self with 431, well it do make a nice white noisegen!

author: iMo
author_rank: Super Contributor
timestamp: August 02, 2018, 08:07:14 am
content: LM385-2.5 (0.3-0.6E/100pcs)?White noise is good for dithering (when you do averaging), btw

author: Andrey_irk
author_rank: Regular Contributor
timestamp: August 02, 2018, 08:37:57 am
content: I like to use REF3033. There are different versions of it and one of them has 2.5V output. These are not that cheap, but I used them to power the micros which saves on a regulator and you don't have to use an opamp to convert 2.5v to say 3v - just get a 3v version. Although the temperature stability is about 30ppm/degC which may not be enough for you if you need wide temp range.

author: iMo
author_rank: Super Contributor
timestamp: August 02, 2018, 09:45:52 am
content: QuoteUsing the internal 12bit ADC in those stm32F1/4 is not easy (mind the external ADC's Vref pin is available with 144pin variants only, afaik). There is usually a lot of induced noise from the MCU's circutry, and, the proper pcb routing is critical as well (4layer pcb may work best). My experience with various F1/F4 dev boards (ebay) is that you may achieve something like ~10bit with it, when lucky. I had to use an external 12bit ADC to be more happy.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 02, 2018, 10:23:21 am
content: LM4040-2.5If you don't actually need 12 bits absolute -- you can afford some calibration time, or better yet your measurement can be made ratiometrically -- a TL431 or even worse will do just fine.Tim

author: IconicPCB
author_rank: Super Contributor
timestamp: August 02, 2018, 10:56:29 am
content: LM723 with self heating setup?

author: Kjelt
author_rank: Super Contributor
timestamp: August 02, 2018, 10:58:39 am
content: IME , the lsb from most internal DACs is noise anyway, check the ref sheet.I even saw applications where it was used to seed a PRNG

author: Giaime
author_rank: Regular Contributor
timestamp: August 02, 2018, 01:05:21 pm
content: Yep, STM32 ADC has got not enough performance to justify an external reference IMHO.Just use as it is for <10bit accuracy or go external ADC.

author: MT
author_rank: Super Contributor
timestamp: August 02, 2018, 06:43:22 pm
content: Many thanks to you all for your thoughts! And to anyone further who leave ideas!Yes F4 ADC is a noise gen in it self, but the spurious crap from internal logic is worst!Time for me to contemplate!
Disable page in Micro-Cap using conditions and directives - Page 1
Forum section: electronics / projects

author: Orion33
author_rank: Contributor
timestamp: August 05, 2024, 08:55:36 am
content: Hi guys. In the latest version of Micro-Cap, you can disable a page via the context menu with a right-click.I would like to know if there is any way to do this through logical conditions and directives on the schematic itself. My research into the documentation has not yielded any results.
Discharging ultracapacitors into a globe. - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: May 28, 2016, 01:22:09 pm
content: Mid last year I bought a set of six 350uF 2.7 volt ultracapacitors on a pcb. I had it connected across the car battery to help with starting. The car has now reached the end of it's life and is soon to be gone, so I have pulled off some of the goodies. Charged up these ultracaps to 15 volts and attached them to a car stoplight globe and let it run down while watching the volts and amps. Went through the movie frame by frame and wrote down the volts and amps and the calculated capacitance on the attached spreadsheet. (poor man's data logger).Video ->https://youtu.be/N1FSPcXzJlo

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2016, 02:13:23 pm
content: QuoteYou're not exactly in the coldest place on Earth! Was your battery (or car) THAT knackered?

author: Circlotron
author_rank: Super Contributor
timestamp: May 28, 2016, 02:55:06 pm
content: The entire car is stuffed. Battery is 5 years old too. 1992, ex cop car, ex taxi. 550,000km. Rusty, registration due in 5 weeks. If you include registration plus all the things needed to get it going again it was adding up to ~$1600 or so. 5 litre motor makes big demands on battery to crank it over.

author: Fungus
author_rank: Super Contributor
timestamp: May 28, 2016, 04:44:55 pm
content: Quote from: Circlotron on May 28, 2016, 01:22:09 pmYou could at least put all the meters the right way up...Love all the ants running around in timelapse.Graph of the results?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 28, 2016, 06:40:39 pm
content: I like it. Clever use of what you have available.

author: Circlotron
author_rank: Super Contributor
timestamp: May 28, 2016, 10:12:24 pm
content: Quote from: Fungus on May 28, 2016, 04:44:55 pmYeah, there's a spreadsheet attached to the first post.

author: Circlotron
author_rank: Super Contributor
timestamp: May 28, 2016, 10:16:51 pm
content: Quote from: Fungus on May 28, 2016, 04:44:55 pmNah, that's just an artefact of you leaning over and viewing it from the northern hemisphere. Here down under it looks fine.
Discover manufacturer from ICChina - Page 1
Forum section: electronics / projects

author: myyosiura
author_rank: Newbie
timestamp: March 29, 2023, 06:37:51 pm
content: Hi everyone!I was testing a flood light and find this two chips, i research a lot an can't find the datasheet, can someone help me find the manufacturer or the datasheets from them?Thank you!
Discrete ADC LDO placement on ADC - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: May 13, 2024, 12:21:47 pm
content: I am making a design that includes discrete ADC. I use an LDO to feed the ADC. I also feed the LDO with SMPS. Why did I use LDO before ADC? Because I want to suppress the ripple. That's why I used an LDO that will suppress the switching frequency of the SMPS before the ADC, as in the analog devices and TI documentation. (Even though the ADC has a high PSRR, I am measuring at the uVolt level, so I do not want to see any switching noise around the ADC).My question here is, is it better to move LDO closer to ADC or keep it closer to SMPS? If we think of it with the logic of finding and eliminating the noise at its source, having the ldo close to the SMPS seems like a better option. So, as I showed in the image, is it better to move the ldo closer to the a or b direction? Any ideas?

author: moffy
author_rank: Super Contributor
timestamp: May 13, 2024, 12:56:59 pm
content: I vote for nearer the ADC as the ground will be closer to the ADC ground, also keep the SMPS switching currents near itself.

author: mawyatt
author_rank: Super Contributor
timestamp: May 13, 2024, 02:54:47 pm
content: Agree.The best location for a regulator is at the load, or point of service generally speaking. This goes for on-chip, PCB, Chassis and Systems.Best

author: MasterT
author_rank: Frequent Contributor
timestamp: May 13, 2024, 05:26:07 pm
content: I see LDO & SMPS, likely ~1V for drop-off margin?My recent discovery that LDO makers cheat in datasheet regarding PSRR and drop-off voltage vs load current. Two parameters "mutual exclusion", means if one is important - disregard another one. To have PSRR >60dB great majority LDO regulators demands 3-5 V Vin - Vout difference. No one provides PSRR vs Vin-Vout in data sheets, here some results I get:// TO-220 Out=3.3V & Vp-p=2V, F-1kHzDiff=Vin-Vout1. LD1117 - 3.7V2. LD33 - 3.7V3. LD1084 - 2.4V4. LM317T(ne LDO) - 3.0V5. LM317T( LDO) - 2.7V6. LM317AHVT - 2.7V7. LM2941+ - 4.5V ** Out=5V min. Vp-p=1V, Vin=9.5V7. LM2991- - 1.2V *"bump" 10kHz -48dB (2kHZ -60dB)V-diff PSRRVolts. dB-1 kHzAP7381 1.5 -60LM2931 1.7 -54LP2950-3,3 1.7 -70L78L33 2.7 -80 * not LDOMCP1702 1.7 -18S-812C-3.5 1.3 -19 No comments. 1uF+1uFS-817B-1.8 0.8 -29 1uF+1uF// SOIC, test: 1uF+10uF, 15 mA, 1 kHz, Vout = 2.5 ВNCV47701 2.5 -60NCV47551 1.9 -51 NR = 0.00uF.NCV47551 1.7 -70 NR = 0.22uF.LM2931A 0.28 -44LM2931A 4.0 >60AP7361A 0.1 >60 5 star *****! 100мВ guaranteed PSSR.NCP731 0.6 >85
Discrete Difference Amplifier - Page 1
Forum section: electronics / projects

author: JoeyG
author_rank: Regular Contributor
timestamp: August 25, 2022, 03:24:17 am
content: AD have a neat little Difference Amp AD8276 and a voltage controlled current source 0 -10mA application note(see URLs below)The beauty is single supply unlike the howland current sources that seems to use op amps with dual supply.The AD8276 doesn't seem to be available and I was hoping to use a generic op-amp for a "loosely spec'ed" variable current source.QuestionThe block diagram of the AS8276 "seems to be" a standard op-amp with internal resistors.Could I replicate this with a standard op-amp and resistors on a single supply?What am I missing that the AD8276 has?The BW required is DC and can tolerate a little bit of driftVoltage source and supply is likely 5V or 12Vhttps://www.analog.com/en/products/ad8276.htmlhttps://www.analog.com/media/en/technical-documentation/application-notes/AN-1530.pdfThanks in advance Joe

author: exmadscientist
author_rank: Frequent Contributor
timestamp: August 25, 2022, 05:12:08 am
content: There are plenty of ways to build a single-supply current source, if you only care about sourcing current or more generally never need the negative rail. Don't feel the need to stick to the AD8276 or this particular circuit (though both are good).The main reason people like the integrated difference amps is their on-package, ratio-matched resistor networks. It is usually cheaper to buy one of these guys than to buy resistors of similar specification for rolling your own discrete version. And it gets you a guaranteed performance spec and a bit of extra bandwidth/AC performance (from the excellent capacitive matching inherent to IC processes). But the discrete version is very possible and works well if you get the resistors right. (Consider Vishay Beyschlag ACAS series resistor networks for SMT work; not the best available, but a real bargain for what you get).Other manufacturers have equivalents to the AD8276. Most notably there is TI/Burr-Brown with a wide range of great parts. I'd look up the best match for you, but they're probably all out of stock anyway. INA592 (equiv. ADI "B grade") or INA597 ("A grade") comes to mind?If you are just building one of these skip the crazy resistors and just make it tunable. The Pease app note (AN-1515) has some good ideas on how to do that.
Discrete Linear Regulator Showing Terrible Open Loop Gain - Page 1
Forum section: electronics / projects

author: EE54
author_rank: Regular Contributor
timestamp: July 07, 2025, 04:29:52 am
content: Hello, I wanted to build a little linear supply (20V, 1.5A) for learning and having an extra supply for my bench.I decided to follow the design of a lot of older HP/Topward where the feedback circuit is referenced to the positive output. The 1st inverting amplifier attenuates the full 20V output to 5V max, and inverts the polarity to + so it can be fed to the error amp(and read by an ADC for display later).Ignore R4/6/7, they’re not used and I forgot to remove them.I tested the phase and gain margin following this video instruction.https://youtu.be/uea3nwd7I4k?si=FAS5VO2uAny-DmgUAnd saw that the open loop gain is very low (90dB at the beginning) and falls off so quickly that the 0dB point is at only 850 Hz.Any idea where I messed up? Thank you.

author: moffy
author_rank: Super Contributor
timestamp: July 07, 2025, 06:00:04 am
content: It looks like you have set the output to zero and so the main transistor is OFF.

author: MariuszD
author_rank: Regular Contributor
timestamp: July 07, 2025, 06:57:32 am
content: The transconductance of the transistor depends on the current. Check the loop gain for different currents.Why are you using an inverting amplifier? Frequency compensation will be easier without it.
Discrete Logic Projects - Page 1
Forum section: electronics / projects

author: tim_
author_rank: Regular Contributor
timestamp: March 04, 2021, 08:57:15 am
content: Hi,I am wondering whether this a good place to discuss discrete logic development? It's very retro technology, but I like it for the puzzle-solving and learning aspect.I noticed one very interesting project on here:https://www.eevblog.com/forum/projects/improving-bandwidth-of-discrete-ecl-logic/My most recent project is the TransistorPixel:https://cpldcpu.wordpress.com/2021/02/27/the-transistorpixel/You can find a lot more on my hackaday.io account:https://hackaday.io/projects/hacker/100317

author: tim_
author_rank: Regular Contributor
timestamp: March 04, 2021, 08:59:20 am
content: To also pose a challenge:The Transistorpixel has a receiver circuit that sets a latch depending on whether a long or a short (<500 ns) pulse is applied to the input.Can you simplify the circuit further? Especially in terms of number of transistors.
Discrete Programmable Shunt Regulator Design - Page 1
Forum section: electronics / projects

author: nathanpc
author_rank: Unknown
timestamp: February 22, 2016, 04:49:17 pm
content: Yesterday I was having some fun experimenting with some shunt regulators for a next project. I started with the resistor and a zener diode, then upgraded to a buffered zener with a TIP31 transistor, then replaced the resistor with a constant current source, and learned a lot along the way, since I never built a shunt regulator before. After all this I decided I wanted the regulator to be adjustable, so the first thing that came to my mind was using a TL431 as the zener diode and I liked the results I got with it, but after a while I had another idea, combine the feedback circuit from awith this shunt regulator and use the B-E junction of the shunt transistor as the reference for the feedback transistor and I ended up with this, the performance is good and I quite like the simplicity of the final result:So, what do you guys think? I haven't seen this before anywhere so I was interested to know your opinion and specially if any improvements could be made. Feedback is greatly appreciated.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 22, 2016, 07:45:49 pm
content: Try a .TEMP sweep...Tim

author: nathanpc
author_rank: Unknown
timestamp: February 23, 2016, 10:24:52 am
content: Haha, well the result was expected, but I forgot it would be greatly amplified by the feedback, do you have any suggestions on how to do some sort of temperature compensation?

author: nathanpc
author_rank: Unknown
timestamp: February 23, 2016, 04:31:02 pm
content: I decided to modify the circuit a bit to improve the temperature coefficient, this is what I could come up with, the results are not great, but they are good enough, I'll think more about this problem and try to improve this even more, then I'll move to other improvements like line regulation, and etc.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 23, 2016, 07:55:28 pm
content: The solution is to build a band gap voltage reference:You use a current mirror, that has a ratio of emitter areas and current densities, to obtain a voltage offset which is independent of temperature (the individual Vbe's have strong tempcos, but the tempco of the exponential slopes cancels out as a ratio).This is only practical if you can pick transistors with emitter area ratios, and exactly matched temperatures. So, ICs. So, just plop in a TL431 instead -- it's also got an op-amp with open-collector output, ideal for your circuit. (Like an op-amp, it needs compensation. With a follower around the outside, probably nothing special. Beware of instability for large capacitive loads.)Tim

author: Kleinstein
author_rank: Super Contributor
timestamp: February 23, 2016, 08:31:29 pm
content: The poor temperature stability is expected when using the U_BE as a reference.A better discrete reference could be obtained from a JFET and suitable adjusted resistor to make it a low TC current source.
Discrete schmitt trigger without separate supply rail. - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: October 09, 2014, 05:59:40 am
content: Trying to cook up a circuit using discrete components (no ICs) to make a schmitt trigger function where the input signal is 0-5V and the upper and lower trip points are say 1.5V and 3.5V. The output voltage is 0-10V. The main design problem is that the circuit cannot have a separate supply rail; besides ground it has to have only one open-collector line to the following circuit. I don't mind trying old timey stuff like UJTs and the like. I'd like to keep the complexity to a max of 4 or 5 transistors because board space is very limited. Any ideas?

author: macboy
author_rank: Super Contributor
timestamp: October 09, 2014, 05:06:15 pm
content: Like this?The turn-on is a little slow. Normally a schmitt trigger has a sharp turn-on, but normally they work with a positive feedback to boost the input when the output turns on. Since you have no power source, I used a sort of negative feedback to the input, which is defeated when the output turns on. The slow turn-on may not be suitable for you.

author: Marco
author_rank: Super Contributor
timestamp: October 09, 2014, 05:42:19 pm
content: Does that still work if V1 doesn't supply enough voltage to turn on Q2? (It had to support output voltages 0-10V.) Still, a lot more elegant than mine (oh and I accidentally made it inverting too, but can't be bothered to fix it).
Discrete through hole MosFETS for push button latch circuit question - Page 1
Forum section: electronics / projects

author: dicky96
author_rank: Regular Contributor
timestamp: August 23, 2017, 03:28:15 pm
content: Hi guysCan someone recommend some easily available and cheap discrete N and P channel mosfets that I can use to build this circuit on veroboard while I am experimentinghttp://www.mosaic-industries.com/embedded-systems/microcontroller-projects/electronic-circuits/push-button-switch-turn-on/latching-toggle-power-switchFigure 3 - Latching Push Button High Side SwitchI want to replace the IRF7319 dual mosfet with discrete through hole N and P channel devices. I will only be switching a very light load of a few milliamps at 3.3VAlso does this circuit need some modification to debounce the push button to get reliable switching?ThanksRich

author: dicky96
author_rank: Regular Contributor
timestamp: August 23, 2017, 06:11:43 pm
content: While waiting for a reply I had a look around on ebayI can get these 4 pin DIL N and P Channel MosFets that look handy for breadboard or veroboard prototyping and they are readily available in UK in packs of 10 for not too much money - and they can switch loads up to an amp or so.Obviously they are cheaper in bulk from china and wait a while for them to arrive....IRFD020 (cheaper option) or IRFD220 N ChannelIRFD9020 (cheaper option) or IRFD9120 P ChannelAre those suitable?Rich

author: colorado.rob
author_rank: Frequent Contributor
timestamp: August 23, 2017, 08:35:47 pm
content: I have used the circuit in figure 5 on that site in the past. It works reliably as is. The switch state can be fed into an MCU to act on short button presses. Just trigger on a rising edge to detect a button press. The logic gates are easy to get in anything from massive DIPs to tiny DFNs.The 1uF cap on the circuit in figure 3 provides adequate de-bounce.

author: Kalvin
author_rank: Super Contributor
timestamp: August 24, 2017, 07:04:45 am
content: If you do not find suitable through hole components, just go to eBay and search for "PCB adapter". You will get quite many different nice SMD to TH adapter boards that are useful for prototyping.

author: dicky96
author_rank: Regular Contributor
timestamp: August 24, 2017, 08:51:04 am
content: Perfect solution - thanks KalvinRich
Discussion regarding professional soldering station JBC vs Ersa vs Weller  - Page 1
Forum section: electronics / projects

author: MuonNeutrino
author_rank: Newbie
timestamp: May 08, 2017, 02:01:18 pm
content: Dear EEV Bloggers,I had a doubt about reaching conclusion which soldering station should I acquire. Furthermore, I need your sincere advice fulfilled by your experience in order to reach final decision.Here is list of the important points that are personally important to me:1. Price is not an issue, nor the deciding factor2. High Quality and Long life expectancy is the imperative for the soldering station3. Soldering tip should not have issues with thermal loss during prolonged session of soldering4. Actual station should be intelligent5. Ergonomics of the iron itselfSince there are very good market for the soldering stations present, I will lower my choices to these stations:ERSA I-Con 1VWeller WT1010Weller WXJBC Premium line either precision or Heavy dutyThe application for which I will be using the soldering station will be in the both smd and regular electronics prototyping, so future tool upgrading is the option to consider. As I already know that each of these brands offer the proprietary smd tweezers and similar options, this choice variety makes me even harder to reach conclusion.Thank you very much.PS: If I missed the proper thread, or place for this type of question please excuse me, since Im new to the blog.

author: capt bullshot
author_rank: Super Contributor
timestamp: May 08, 2017, 02:22:26 pm
content: Ersa - first brand name in Germay, but has been a bit disappointing to me, wouldn't buy Ersa again. Mainly because of various failures of the soldering ironsWeller - just works as expectedJBC - best I've ever seen, if cost isn't a concern, I'd buy nothing else

author: digsys
author_rank: Unknown
timestamp: May 08, 2017, 02:32:11 pm
content: There's a few extensive threads on the exact same subject. Have you checked them out first? A lot of input.

author: MuonNeutrino
author_rank: Newbie
timestamp: May 08, 2017, 04:40:29 pm
content: I have read many of the forum pages, but nobody, since now, is actually comparing the top of the line brands and their top of the line products.So I have rather sweet dilema and problem. I have situation where money does not dictate the product, but I can not decide which product should I buy.Thanks for understanding.

author: stj
author_rank: Super Contributor
timestamp: May 08, 2017, 05:23:20 pm
content: if money is no object,i would buy this:http://www.ebay.co.uk/itm/Universal-soldering-controller-for-Hakko-JBC-and-etc-soldering-UniSolder-5-2-/222478565688it's a fully built clone of this:http://dangerousprototypes.com/forum/viewtopic.php?f=56&t=7218i'm going to order some pcb's soon and make a couple myself.you still need to buy the iron(s) btw - but with this, you can just swap between the ones you listed!!
Diseño de una Fuente Flyback con MC34063 - Page 1
Forum section: electronics / projects

author: nico_2006
author_rank: Newbie
timestamp: March 29, 2025, 12:55:42 am
content: Estoy diseñando una fuente flyback utilizando el IC MC34063 con el objetivo de elevar la tensión de 12V a 500V y proporcionar una corriente de salida de 10mA. Mi idea es que la salida sea regulable mediante un potenciómetro, modificando la tensión de retroalimentación (feedback). Esta fuente está destinada a alimentar pequeños amplificadores valvulares y a reformar capacitores.Para el diseño, utilicé las fórmulas proporcionadas por Electgpl, pero al realizar una simulación en Multisim, obtengo aproximadamente 70V de salida en lugar de los 500V esperados. Me gustaría que alguien con experiencia en fuentes de esta topología me ayudara a verificar si los cálculos que realicé son correctos y, en caso contrario, me orientara sobre cómo corregirlos.

author: mr ed
author_rank: Regular Contributor
timestamp: March 29, 2025, 10:20:23 am
content: 500v over 42k ohm is 6 watts, not 0.75wBallpark, something off by a factor of 10?Also, transformer output impedance is the square of the turns ratio.So 40 to 1 is 1600 times the input z.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 29, 2025, 12:00:37 pm
content: On this forum post using English only, please.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 29, 2025, 03:16:31 pm
content: Compare your derivations with thishttps://passive-components.eu/flyback-converter-design-and-calculation/
Dismantling a Philips LED light - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: December 12, 2020, 06:58:18 am
content: I have some of these 12v lights which only startup when the supply voltage is close to 12v. Once running they continue to work at lower voltages. I would like to bypass the existing controller and use my own which doesn't have the annoying 12v startup threshold.Any idea how to dismantle it with minimal damage. The back half looks like glass, but the front face sounds and feels like plastic. If I pry the front off do you think I'll be able to get at the electronics behind the LED module without destroying it?
Disparity Between Datasheet and S-param Model for Mini-Circuits Transformer - Page 1
Forum section: electronics / projects

author: niconiconi
author_rank: Frequent Contributor
timestamp: October 18, 2019, 08:23:58 pm
content: It's me again, asking another RF noob question.I'm trying to learn the behavior of a RF impedance transformer at different frequencies, and I used Mini-Circuits T16-1-KK81+ (0) (impedance radio 1:16) as my example. I want to look at its complex impedance (S11) on a Smith Chart when the secondary is terminated with a matched load. Mini-Circuits provided a raw 4-port S-parameter model (1) measured by a VNA for simulation, so I downloaded the model and imported it in the Qucs simulator and obtained some results.The shape of the curve is identical, but the numerical values don't match the S11 shown in the datasheet (2), S11 has an error of around 6 dB, please see the attached screenshots. For exmaple, the return loss in datasheet is around 2 dB at 100 MHz, but the simulator says it's 5 dB.Is it possible that my simulation setup is incorrect? I'm sure it's not a glitch in the simulator, I tried ADS2008 and I obtained the same results. I believe the different is due to the fact that the device is measured under different conditions, the official return loss figures are measured with a matched 800R load, but the S-parameters are measured by a 4-port 50R VNA, so the error is inevitable? Is it the correct interpenetration of my results?Also, the Smith Chart shows the transformer becomes capacitive at high frequencies, is it normal? I would expect a transformer to be inductive.---(0)https://www.minicircuits.com/WebStore/dashboard.html?model=T16-1-KK81%2B(1)https://www.minicircuits.com/pages/s-params/T16-1-KK81+_S4P.zip(2)https://ww3.minicircuits.com/pdfs/T16-1-KK81.pdf
Display CCFL as a worklight help. - Page 1
Forum section: electronics / projects

author: Mutad0r
author_rank: Contributor
timestamp: February 25, 2015, 04:25:42 pm
content: For too long I have worked in the dark and have now decided to get a decent work lamp. Only problem: there aren't any decent desk lamps available at stores where I live, I spent the whole day driving around stores (actually it was an hour [ it's a small town ] ).I have now decided to use stuff that I have laying about and make my own. I have a case load of LED brake light strips, but they're red so they're no good. I have 2 white LED light strips that would be great, but that's not good enough for me either! I also have 2 pairs of scavenged CCFL lights that I got from some old and broken LCDs which would be perfect.The problem is that I haven't found any useful information on how to use them. Sure there are schematics available, but that's not good enough. I don't like making high voltage circuits myself, so I figured I'd buy one, there are some available on ebay, but before I make a decision, I would like to know a bit more.One thing I would like to know, is the colour code of the CCFLs, there are Blue, Black, Pink, Yellow/White. Googling for that information mostly gives you stuff about how to wire CCFL angel eyes.The other thing is how do I know the correct voltage, and is there even such a thing as a correct voltage.I'm not afraid to brake them, for they were free and I'm not emotionally attached to them, but I'd rather not dive in willy-nilly, so any information on how to use an LCD display CCFL or CCFLs in general would be great (wikipedia lacks practical information on the subject).Also, I figured the following CCFL driver could do the job, if you have any comments on that, feel free to share:http://www.ebay.com/itm/4-Lamp-Backlight-Universal-Laptop-LCD-CCFL-Inverter-10-30V-For-15-26-Screen-AU-/380964054054?pt=AU_Laptop_Accessories&hash=item58b33a2426

author: kezat
author_rank: Contributor
timestamp: February 25, 2015, 05:06:46 pm
content: I had the same issue for some time with a dark work area. My solution was the common spools of LED light strips that you can pick up for about 10$ and use one of the many 12v power supply's I have laying around.Like this:http://www.amazon.com/Lampux-Flexible-Lights-Daylight-Waterproof/dp/B00HSF66JO/ref=sr_1_10?ie=UTF8&qid=1424883873&sr=8-10&keywords=waterproof+led+lightsThat is just a random link to the first I found you might get a better deal some place else.

author: Mutad0r
author_rank: Contributor
timestamp: February 25, 2015, 05:37:24 pm
content: Quote from: kezat on February 25, 2015, 05:06:46 pmYes, LED light strips are.... COOL... I have a few RGB spools and a white one. They are my second choice for lighting atm, the main reason I have for using the CCFLs is "Why not". I mean, I have them, so I might as well try to use them.
Display - Cheap and Large - Page 1
Forum section: electronics / projects

author: sidereal
author_rank: Contributor
timestamp: November 21, 2021, 09:16:23 pm
content: HiI am looking forward to build a medical routine and tracking unit for myself.I want to have nice wall covering visualizations. This is my idea :I like the modular nature of things, and will go that route.As you can see, I need 56 Screens.It'd be very cool to have something like this Sony Ericson Xperia Pureness :But such things are too difficult to read (low contrast).I have considered :https://www.exp-tech.de/displays/e-paper-e-ink/8895/waveshare-2.7-e-ink-raw-display-264x176?c=1424But doing this means i will have to shell out ~ 600 € + the SPI drivers. But this is too expensive. I need some cheaper alternative.What are my options ? My requirements are :Size : 3 inch to 5 inchesDrive Over SPI, hopfully over Arduino. If not possible, then I am open to ESP / STM32 as wellLow power consumption : <0.5 mW. If at all not possible - then i can work my way up to 10 mW max (yes, 3 orders of magnitude change)Resolution : around 170x170 or moreTo reiterate, Cheap and low power are also important to me. I am willing to shell out about 4-6 € per unit.I look forward for your recommendations. Thank you.-Sideral

author: Berni
author_rank: Super Contributor
timestamp: November 22, 2021, 06:27:15 am
content: Yep sounds like you instead want to get a large TV or one of those laser micro projectors. Likely a cheaper solution and you can run it from the HDMI port on a raspberrypi