hybridfree/eevblog-posts huggingface dataset:
Tested variable power supply to recommend me that use 2N3055? - Page 1
Forum section: electronics / projects

author: samsagaz
author_rank: Contributor
timestamp: March 23, 2016, 04:25:24 am
content: Hi guys, i have some(10) 2n3055 to build a variable power supply i want at least 5A 30V output, was thinking about use two transformers to get two outputs.Can someone recommend me some PSU design to build?Thanks in advance

author: Vgkid
author_rank: Super Contributor
timestamp: March 23, 2016, 05:08:52 am
content: Does your power supply need to go to 0.0v, or are a few volts ok?

author: samsagaz
author_rank: Contributor
timestamp: March 23, 2016, 05:09:52 am
content: a few vols will be OK!, think that to get close to 0v will be a little hard

author: Kleinstein
author_rank: Super Contributor
timestamp: March 23, 2016, 07:23:03 pm
content: I would recommend something similar to a commercial supply from about the 1980s. The TTi TS3021 might be one to look at (though only 2 A). It's usually not much extra effort to go alle the way down to 0 V.With so much power I would consider using at least two transformer taps to reduce the heat generation. At 30 V and 10 A the power is rather high to do this by relays. If you are new to building a supply one should start smaller e.g. 1-2 A first - less magic smoke to escape.

author: rdl
author_rank: Super Contributor
timestamp: March 23, 2016, 08:19:49 pm
content: Many high current supplies have been made for the amateur radio market and other uses with parallel 2N3055s controlled by an LM723. Pyramid and Astron are two suppliers I know of. I also have several open frame supplies that are basically the same thing but with just one 2N3055. It shouldn't be too hard to find a schematic.

author: Andy Watson
author_rank: Super Contributor
timestamp: March 23, 2016, 08:32:21 pm
content: Quote from: Kleinstein on March 23, 2016, 07:23:03 pm+1. Also look at the Farnell 'L' series - especially the L30/5.

author: mmagin
author_rank: Frequent Contributor
timestamp: March 23, 2016, 10:10:37 pm
content: Just keep in mind that the archaic 2N3055 has pretty poor gain at high currents, and mind the safe operating area!(There's at least one current manufacturer of 2N3055 that doesn't show a SOA in the datasheet -- I wouldn't believe them)
Testing 5V ARGB lights for current - Page 1
Forum section: electronics / projects

author: DW1961
author_rank: Frequent Contributor
timestamp: January 06, 2021, 07:00:37 pm
content: I've been bench testing 12V RGB lights for current, but I want to test ARGB lights now.The 12V RGB is simply because it has a power connection and then the LED light connection only. That way I can test each channel (R G or B), or just put the power to all three and get total amps at 100% duty.The ARGB, however, has 3 connections, power, negative, and data. How would I go about bench testing to check total amperage, which means all lights on 100%?

author: LexLabs
author_rank: Contributor
timestamp: January 08, 2021, 04:52:26 pm
content: Quote from: DW1961 on January 06, 2021, 07:00:37 pmHi, I guess one of the methods is to use a microcontroller to drive all the lights High and then measure the current using a multimeter/Ammeter.

author: phil from seattle
author_rank: Super Contributor
timestamp: January 08, 2021, 05:40:56 pm
content: ARGB is more of a marketing description - A stands for Addressable. What is the part number of the LEDs? I'd guess WS2812 or some such. Usually strings marketed as ARGB have a controller that drives them. If it's a bare string, then you will need to do what LexLabs said. The good news here is that once you ID the LEDs, there are plenty of libraries out there.

author: DW1961
author_rank: Frequent Contributor
timestamp: January 08, 2021, 08:59:53 pm
content: Quote from: phil from seattle on January 08, 2021, 05:40:56 pmI may have to buy a 5V controller on amazon, cut the SATA power plug off, and then attach my power supply leads.

author: Zero999
author_rank: Super Contributor
timestamp: January 08, 2021, 09:07:14 pm
content: Quote from: phil from seattle on January 08, 2021, 05:40:56 pmThanks. I didn't know that. I assumed it meant Amber, Red, Green, Blue!

author: phil from seattle
author_rank: Super Contributor
timestamp: January 08, 2021, 11:58:18 pm
content: Quote from: Zero999 on January 08, 2021, 09:07:14 pmOr, in the spirit of truth in advertising, Almost RGB.
Testing a bench power supply. Transient test  - Page 1
Forum section: electronics / projects

author: diydidi
author_rank: Contributor
timestamp: April 24, 2016, 09:01:46 am
content: Right, so I have just finished building my power supply. Its a 0-50V 0-4Amps bench supply.I have an electonic DC load that can do transient tests on power supplies.I just recently purchased this load.How do I go about testing my power supply. I have no idea at what current rating to set the dc load and at what frequency i should set it's on/ off cycle.What waveforms should I expect to see ?I have done a capture of the on waveform at switch on. Looks good no overshoot.I forgot to mention the dc load has the following parameters that can be set for transient testing.Start currentEnd currentRise timfall timeOn timeOff timeHope someone can give me a couple concrete steps to test my power supplyThanx.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 24, 2016, 09:57:50 am
content: The typical test is a load transient, so fast steps in load current between two currents. There are several steps that make sense:1) To compare with other instruments the same steps should be used, e.g. 100%-50% steps.2) To check for the performance at low currents, use transients of something like 1 A - 1 mA, and 1 A - 10 mA.As the critical load is a capacitive one, one might want to also do a test with a relatively large low ESR cap (e.g. 5000 µF) at the output. This can show trouble with some supplies.The frequency can be rather low, just to get a stable picture on the scope. So it could be even single shots with DSO. To many transients in a short time might even damage relays used to switch transformer taps.On a rising current you are expected to so see a fast drop in voltage by something like 100-500 mV and than an recovery within something like 100 µs. Often the recovery is not a single exponential but two stages: most of it fast (e.g. 10 µs) and a small rest of something like 10% with a longer time constant (e.g 100 µs). On a falling current it's opposite sign. At low currents there may be extra oscillations / slower response. With the large capacitive load, especially if really low ESR, there can be some ringing at rather low frequency, though low amplitude.

author: JoeO
author_rank: Frequent Contributor
timestamp: April 24, 2016, 01:46:33 pm
content: Did you design the supply or did you get the schematic from somewhere?If you found the schematic online, it would help to supply a link to the schematic.
Testing a Converter Module Step Down from 12V to 5V....  - Page 1
Forum section: electronics / projects

author: ziomario
author_rank: Contributor
timestamp: February 27, 2025, 09:01:53 pm
content: Hello.What happens if I connect the male barrel jack to the connector of the little board that you see below ? is there some risk of explosion :D ?What is whatmini table fan : 5 watthttps://www.amazon.it/dp/B0CXXG1BXX2) battery pack : (Liitokala battery pack ioni di litio 12V 3000mAh 12V 3A) :https://it.aliexpress.com/item/32381410408.html3) board : (EPLZON DC 6V 9V 12V 24V to DC 5V 5A Buck Converter Module V-36V Step Down to DC 5V-5.3V 5.2V 3.5-6AEPLZON DC 6V 9V 12V 24V to DC 5V 5A Buck Converter Module V-36V Step Down to DC 5V-5.3V 5.2V 3.5-6A)https://www.amazon.it/dp/B0B58T2YY8Check attachments.

author: MIS42N
author_rank: Frequent Contributor
timestamp: February 28, 2025, 04:07:38 am
content: I think it should work OK. Put a switch and a fuse (say 500mA) between the battery pack and the buck converter to be safe. Make sure you get the polarities right before testing, most barrel jacks have the center pin +ve but not always true.

author: ziomario
author_rank: Contributor
timestamp: February 28, 2025, 08:12:27 am
content: Thanks.According with the display specs that I'm using in my mini-pc :https://www.waveshare.com/wiki/8HP-CAPLCD_Monitorit seems that it typically uses 800 mA.so. Can it be powered on with my buck board and the liitiokala battery pack without running the risk to burn it,in your opinion ?I should use it with the USB 3.0 port,not USB 2.0...
Testing a Custom Built Light Strip BEFORE Blowing my Computer up. - Page 1
Forum section: electronics / projects

author: DW1961
author_rank: Frequent Contributor
timestamp: July 15, 2020, 07:23:26 pm
content: I want to test my custom built (soldered) strip before smoke testing them on my motherboard.I'm going to check for continuity and current, but will that do it? Or, is there something else I should check also?

author: spudboy488
author_rank: Regular Contributor
timestamp: July 16, 2020, 11:31:15 am
content: Check for shorts between ground and power.Check for shorts between ground and any signal that will be driven by the PC CPU.Check for shorts between power and any signal that will be driven by the PC CPU.Basically, you don't want to short the PC power supply or have the CPU try and drive a ground short high or a VCC short low.

author: DW1961
author_rank: Frequent Contributor
timestamp: July 16, 2020, 07:38:04 pm
content: I'm less worried about the PSU unit. They are pretty well protected. I'm worried more about toasting the RGB fets. So I want to test the strips when I get done soldering them. The only thing I know to do is run an AMP and Continuity check on them. I'll also check the MB riser for correct voltage.Anything else?

author: DW1961
author_rank: Frequent Contributor
timestamp: July 22, 2020, 05:12:50 am
content: I'm talking about testing the strip itself to make sure it isn't shorted out in a way that will cause the Fets on the Motherboard's RGB circuit to melt.Would just testing the strip with continuity and amperage do it, or are there other things that could case my MB's RGB fets to go "Up In Smoke" that continuity and amperage would not show?
testing a mixer for saturation - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: December 25, 2024, 07:23:31 pm
content: Hello , I am using a DBM shown bellow TXF-18075,unlike amplifier Its mixer is more complicated.How can I see in the lab the saturation on my DBM?How can I see that LIVE the saturation and see if I have a good LO or RF signal?Thanks.

author: bairdbankovic
author_rank: Newbie
timestamp: December 25, 2024, 11:42:44 pm
content: Feed in a waveform and use an o-scope to check for clipping? Am I missing something here?

author: john23
author_rank: Frequent Contributor
timestamp: December 26, 2024, 03:33:33 am
content: I have two power levels the IF and LOHow do I test for clipping when there are two possible problematic power sources, maybe the LO power is two low ?How can I see that my LO is too low ?Thanks .

author: john23
author_rank: Frequent Contributor
timestamp: December 27, 2024, 07:33:34 am
content: What si the LO is too low.I dont have a datsheet.Thanks.

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: December 27, 2024, 07:48:18 am
content: Generally +10dBm is good enough for double balanced mixers. If you have two signal sources, set the RF to -30dBm and plot the conversion loss vs LO power. You can see when the conversion loss levels out, and that is your minimum LO power.Here is some random picture I found on the internet. You can see that somewhere around +7dBm LO power is ideal for this mixer.You can also determine the input IP3 of your setup. Attach an isolator on the output and feed a slightly offset signal from a signal generator back in (like maybe input frequency + 1kHz). Make sure that your signal generator can take reverse power (some power will leak through the isolator). You can then determine linearity by measuring the 3kHz harmonic on the IF of the mixer.

author: john23
author_rank: Frequent Contributor
timestamp: December 28, 2024, 07:54:54 pm
content: Hello eggerEnjoyer,I have three ports,RF LO IF.I use this mixer in downconverting.So I need to block and cancel the IF so nothing will return.Where do i need to feed the signal?Ip3 is spposed to be the input at which the output is compressed.our output is blocked.WHat is the logic in this method?Thanks.You can also determine the input IP3 of your setup. Attach an isolator on the output and feed a slightly offset signal from a signal generator back in (like maybe input frequency + 1kHz). Make sure that your signal generator can take reverse power (some power will leak through the isolator). You can then determine linearity by measuring the 3kHz harmonic on the IF of the mixer.
Testing a VN05N - Page 1
Forum section: electronics / projects

author: cs.dk
author_rank: Unknown
timestamp: November 17, 2013, 09:42:35 am
content: Is it possible to test a VN05N for any damage, either in circuit or as a standalone component? Datasheet here:http://pdf.datasheetcatalog.com/datasheet/SGSThomsonMicroelectronics/mXuqvut.pdfReason is, that many Citroen Xantia and XM uses these transistors to activate soft suspension-mode, but because of flyback from the coil/solenoid they break down over time. I've got new VN05N's and some 1N5822 diodes, so I should be able to fix the ECU's i've got. But it would be nice to know if the VN05's in the ECU actually is dead, before just replacing them on a row..

author: SeanB
author_rank: Super Contributor
timestamp: November 17, 2013, 10:22:28 am
content: Diode test between drain and source, along with the same between gate and source. If there is any short circuit or leakage just change it. Forward voltage should be in the same ballpark as a regular silicon diode on the meter, reverse should be open circuit with the load disconnected. Gate may show some due to the driver, but check on each side of any gate resistor to see that at the driver side the voltage will be slightly lower.
Testing Ctek M100 12V Charger with Riden 6018P Bench PSU? - Page 1
Forum section: electronics / projects

author: ElectricPower
author_rank: Frequent Contributor
timestamp: December 17, 2023, 07:40:12 am
content: I have an faulty Ctek M100 car charger (12V) that do not charge in normal mode regards to the owner of the charger. I do not have any 12V battery to test with, so i wonder if i can use my Riden RD618P bench power supply to simulate the battery voltage to the clips?My consern is the current that the charger may putting inn to my PSU. Some ideas?

author: tunk
author_rank: Super Contributor
timestamp: December 17, 2023, 04:17:59 pm
content: AFAIK, you cannot use a PSU as an electronic load (unless it's specifically designed for it).

author: ElectricPower
author_rank: Frequent Contributor
timestamp: December 17, 2023, 07:04:12 pm
content: Quote from: tunk on December 17, 2023, 04:17:59 pmI know.But i just want to simulate that there is an battery connectet for testing the circuit in the charger. Will the charger push current inn to my PSU and if yes, can my cpu handle it?

author: floobydust
author_rank: Super Contributor
timestamp: December 17, 2023, 09:35:20 pm
content: What I will do to spoof a car battery is take a bench power supply (that can take backfeed or use an isolation diode) and dial it to say 11V feeding a car light bulb like a 2057 taillight or car headlight for higher current testing.So the lamp is lit, then I connect the smart charger to go through it's sequence. If it starts charging the lamp should go brighter and see the voltage go up. The charger overtakes the bench PSU output which has a lower V setpoint. The RD6018 is advertised as being able to charge batteries.It's complicated because some smart chargers have poor firmware. They can get confused by the battery appearing fully charged so quickly, if the voltage hops over 14V say. So the lightbulb load needs to keep it below the charging finished level.CTEKchargers have cheap electrolytic capacitors inside which go bad. The enclosure doesn't let heat out either, no vents. But the M100 is marine splashproof.All that hype and marketing and Swedish design, "the smartest charger in the world" - yet they get the hardware built in china using cheap caps. So they don't last.
Testing dielectric strength on secondary side of power supplies - Page 1
Forum section: electronics / projects

author: AndersJ
author_rank: Frequent Contributor
timestamp: February 23, 2016, 03:25:27 am
content: Some standards require testing of dielectric strength on the secondary side of the power supplies,and all sub systems on the secondary side.This is done by shorting all signal lines and applying a high voltage referenced to chassis ground,while the device is turned offThe measured current must be low, for instance < few mA.Many systems have signal ground galvanically connected to chassis.Needless to say, the test will fail.How is this handled, in for instance a PC, where signal ground is connected to chassis?Is the correct approach to isolate signal ground from chassis, with a HV capacitor,and possibly a high value resistor to loosely tie them together dc-wise?

author: oldway
author_rank: Super Contributor
timestamp: February 23, 2016, 10:01:15 am
content: Many systems have signal ground galvanically connected to chassis.If secondary power side is also grounded, I think you must only make a dielectric test between primary power circuit and ground.

author: AndersJ
author_rank: Frequent Contributor
timestamp: February 23, 2016, 12:58:44 pm
content: If signal ground floats relative ground,is it correct to assume that signal ground is one of the "signal lines"and therefore subject to surge injection vs ground?

author: oldway
author_rank: Super Contributor
timestamp: February 23, 2016, 02:27:40 pm
content: I think that in this case, you must apply the rules of reinforced insulation, class 2, EN/IEC 61010-1 catII 300V, that's3150Vdc3000Vac or 4200Vdc during 1 min.applied voltage between high voltage power circuit and control.For basic insulation (300V), testing dielectric strengh must be done with 1500Vac or 2100Vdc applied during 1 min.
Testing EMP Jammer on Microwave (Boom!) - Page 1
Forum section: electronics / projects

author: Kedar264
author_rank: Regular Contributor
timestamp: October 13, 2015, 06:28:36 pm
content: Expensive Experiments That You Shouldn't Do AtYourHome !# Destroy Microwave With Emp Jammer#How To Make Emp Jammer# Whole Emp Playlist !https://www.youtube.com/playlist?list=PLAQHyp2rW378r39L7VruL6n9l9vZynZsoi Sacrifised lot of devices while this experiments ,Enjoy Watching thisDon't Try This if You Have No Idea How Dengerous (Or Last Experiment ) It Can Be !

author: oldway
author_rank: Super Contributor
timestamp: October 13, 2015, 07:10:08 pm
content: Interestingly, this shows how a microcontroller is fragile.But this we already knew.I remember that in the eighties, we were testing the analog circuits we were developing by connecting an old electro-mechanical doorbell (without capacitor) on the 12V power rail and everything should operate normally despite all electrical disturbances generated by the doorbell.I doubt that we can still do the same test with microcontrollers.

author: dmills
author_rank: Super Contributor
timestamp: October 13, 2015, 07:21:56 pm
content: Story goes that back in the day, Calrec Audio (Makers of big scary mixing desks) used to do immunity testing (Back before there was such a thing) with a car ignition system driven by a motor and with a pair of telescopic dipoles brazed onto the sparkplug, getting anything to pass was apparently fairly heroic (The definition of 'pass' they used was rather tighter then the one in the modern rules).Those little black 3V potted boiler ignition modules strike me as having similar possibilities, might have to build such a thing and take it to the next HIFI show......Regards, Dan.

author: calzap
author_rank: Frequent Contributor
timestamp: October 13, 2015, 08:20:17 pm
content: I'd be very careful about where such a device is taken. Would not want to be forced to explain what it is to an airport security agent. Could also be considered a RFID zapper, which it is, if found on you in a store. I didn't see an FCC compliance sticker on it!Mike in California
Testing EtherCAT - Page 1
Forum section: electronics / projects

author: mrburnzie
author_rank: Regular Contributor
timestamp: March 06, 2024, 11:39:15 am
content: I want to test if my EtherCAT master hardware is working correctly.What is my best approach here?Get a module like a LAN9252 andwith the firmware or just get an already ready to use EtherCAT slave sensor module? Is there a third option?

author: jbb
author_rank: Super Contributor
timestamp: March 07, 2024, 05:09:32 am
content: For a company: Someone (Tek?) make a great oscilloscope with an honest to goodness 10/100 Mbit Ethernetserial decoder. See if you can borrow one for a week of evaluation.Or for us mortals who can’t borrow one, I recommend getting two basicbut compliantEtherCAT slave units. Start with just one, and once you think you’re working move to two…
Testing feedback functionality of an analog controller - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: February 21, 2025, 04:02:58 pm
content: Hello,I have built an LTspice simulation of a PID controller based on this youtube video.The basic schematic is presented. The AD797 model was used to construct all the blocks.A PID controller was built by the schematic and the AC response is presented.I tested with AC response each stage but I don't want to overwhelm with plots.Basically I am used to test my circuit in AC response, but it doesn't say much to me.In AC response we test stability and gain but the PID is designed to do feedback.What method is used to test the PID feedback capabilities?LTspice files are attached.
testing LM324 OP-AMP - Page 1
Forum section: electronics / projects

author: hussamaldean
author_rank: Unknown
timestamp: March 17, 2018, 05:35:44 pm
content: Hi,I want to build PWM generator circuit using this op-amp. however, I start to doubt that the op-amp is not working since it doesn't draw any current from my PSUis there any way to test if it does work ?Regards

author: Brutte
author_rank: Frequent Contributor
timestamp: March 17, 2018, 05:47:27 pm
content: If it does not draw any current (i<1pA) then there is no need to investigate that part further.Idling device should draw idle current, more or less.

author: precaud
author_rank: Frequent Contributor
timestamp: March 17, 2018, 05:49:31 pm
content: : Double-check your supply voltages.: Short pin 1 to pin 2: Put a 1kHz signal into pin 3: Measure at pin 1, should be the same as the input at pin 3.

author: hussamaldean
author_rank: Unknown
timestamp: March 17, 2018, 06:22:32 pm
content: Quote from: precaud on March 17, 2018, 05:49:31 pmI'll test it soonQuote from: Brutte on March 17, 2018, 05:47:27 pmI can't be 100% sure since my psu has 10mA resolution only (Uni-t UTP3315TFL)so basically I can't be 100% sure

author: Zero999
author_rank: Super Contributor
timestamp: March 17, 2018, 06:51:06 pm
content: Post the schematic.The LM324 seems to be a poor choice for a PWM circuit, because it's very slow.

author: hussamaldean
author_rank: Unknown
timestamp: March 17, 2018, 07:05:47 pm
content: Quote from: Hero999 on March 17, 2018, 06:51:06 pm

author: Zero999
author_rank: Super Contributor
timestamp: March 17, 2018, 07:18:33 pm
content: Quote from: hussamaldean on March 17, 2018, 07:05:47 pmThe LM324 is no good for that circuit. Use a comparator IC with a push-pull output, such as the LMC6762 or TLC3702. Alternatively, the LM393 or LM339 will work with 1k pull-up resistors to 5V.You'll need to make sure the MOSFET can pass the required current, with a gate voltage of 5V. Consider powering the PWM circuit off 9V, directly from 12V or using a MOSFET driver IC.What's the maximum expected supply voltage? Will this be run off a car's electrical system? It may be necessary to add some overvoltage protection circuitry

author: hussamaldean
author_rank: Unknown
timestamp: March 18, 2018, 04:18:13 am
content: Quote from: Hero999 on March 17, 2018, 07:18:33 pmthe circuit for reference, I will use L298D motor driver though
Testing my nA my current source - Page 1
Forum section: electronics / projects

author: Terry Bites
author_rank: Super Contributor
timestamp: June 26, 2025, 05:53:46 pm
content: I've been musing on a generalized impedance converter based precision current source. A sketch from my notebook but it would have been lifted from a journal.Anyhow, I thought I'd give it a go. Aiming for very low currents down in the nA I realised that only fet input or zero-drift opamps would work.And so far, so good on 400Hz and DC. I used a pair of (pA) jfet buffers to measure the voltage across Rl. I got to 1Gohm before it cielinged out.My early indications are that compliance to >10V is possible at 100nA and lower.One of the strange things is that it is remarkably insensitive to resistor mismatch. I haven't got my head around that yet, any ideas why that should be?I put it all on a tiny pcb with some SMA connectors and some guard traces around the high impedance nodes. All of the opamp inputs except the non-inv of U1a.Cost about 30 quid, not bad. It’s a novelty project, I can’t imagine I'd have a real-world application!I am thinking that I might stick a mosfet buffer on the drive opamp and try it at higher currents. See idea below. Maybe a bipolar buffer would increase the compliance range somewhat.A small leakage current ~Io/1000, a 0.1% error term will flow from the load back into the sense opamp. A buffer would be a good idea here. i havent really looked into pulse response/ compensation/ stabilty yet.I'm thinking (fantasising) about running it from an isolated supply, flaoting floater so to speak.Marco Reps has a great video on how to get rid of common mode noise issues.Errata, the opamps are LTC2057s.

author: moffy
author_rank: Super Contributor
timestamp: June 26, 2025, 10:42:58 pm
content: The symmetry between U1a and U1b and the connecting of both feedback -ve inputs is not something I've seen before. It will take a little bit to mull it out, thanks for the post.
Testing my new self-made 3D-printer (video) - Page 1
Forum section: electronics / projects

author: Kaptein QK
author_rank: Regular Contributor
timestamp: June 12, 2013, 09:27:04 pm
content: Made with 30x30mm equal angle aluminum profiles and 8mm rods.The extruder is bought as a kit, can not remember the name.Steppers: 17 sizeStepper drivers: THB7128Controller board: Arduino Mega2560Idlers and holders made on a lathe.Timing belt is from a T-REX 500 RC helicopter.Written in AVR GCC, no Arduino IDE where used (it sucks)PC host written in Java (Processing) (it also sucks)Source code is attached.Don't mind the test object!

author: Adler
author_rank: Regular Contributor
timestamp: June 13, 2013, 12:24:28 am
content: Awesome!!! Print off a couple and make some coat hooks... or doorknobs... or toiler flusher... or custom handle for an oral irrigator. The possibilities are endless.I just hope you don't have a 3d scanner as well.

author: Kaptein QK
author_rank: Regular Contributor
timestamp: June 14, 2013, 08:56:34 pm
content: Haha, no, I found the model on the internet

author: Fraser
author_rank: Super Contributor
timestamp: June 14, 2013, 10:30:20 pm
content: Nice piece of engineering and though I note your comment regarding the model.....why on earth would you need another penis

author: Kaptein QK
author_rank: Regular Contributor
timestamp: June 18, 2013, 09:17:43 pm
content: There is already to many 3D-printed Yoda test objects around!

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 18, 2013, 11:02:48 pm
content: Quote from: Aurora on June 14, 2013, 10:30:20 pmyou should know why a man need another penis. btw Clone-A-Willy, coupled with 3D scanner as mentioned and the printer, can produce more professional, repeatable realistic and unforgettable gift to folks.

author: peter.mitchell
author_rank: Super Contributor
timestamp: June 19, 2013, 03:11:07 pm
content: This seems oddly relevant;

author: xchip
author_rank: Regular Contributor
timestamp: June 23, 2013, 01:58:24 pm
content: Nice! Where did you get those nice timing belts pulleys at 0:34? I want them too

author: firewalker
author_rank: Super Contributor
timestamp: June 23, 2013, 02:09:37 pm
content: It seems to be better than Makerbot.Alexander.

author: Kaptein QK
author_rank: Regular Contributor
timestamp: June 24, 2013, 09:36:49 am
content: Quote from: xchip on June 23, 2013, 01:58:24 pmEbay, as most of the other materialsThe printer can also make other usable things, not just green gentleman bits!See this video:

author: xchip
author_rank: Regular Contributor
timestamp: June 25, 2013, 03:13:42 pm
content: Are these the ones you bought? How much did you pay for them?http://www.ebay.com/itm/XL15-Stepper-motor-XL-timing-belt-pulley-Synchronization-teeth-15-Bore-6-or-6-35-/321137233263?pt=LH_DefaultDomain_0&hash=item4ac5454d6f

author: Kaptein QK
author_rank: Regular Contributor
timestamp: June 27, 2013, 01:00:17 pm
content: No, but they are similar. XL belt, 15 teeth. Can't remember the price, but they where not expensive.
Testing of a Li* cell management system, what is the best approach? - Page 1
Forum section: electronics / projects

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 10, 2017, 08:53:07 am
content: Hello!For the past months i have been building a small open source handheld LED light.I want to test the circuit as thoroughly as i can before i put the final schematics online for others to build their own.But i ran into a small problem, i can simulate a bunch of conditions and failures but i have a hard time testing the battery circuit properly.I need a Voltage source that can sink current to simulate battery charging, i can get around that to an extend with my bench power supply but i can not sink current with that.The next best tool i could find, that would do that, is a source measure unit but after i had a look what they cost, that is out the window.I lack suitable search terms to ask google for it, all i can come up with does not lead me were i want to go.If that is not enough information, here is my project page for the light, that is all the information i have:https://hackaday.io/project/21001-brightenmacherThank you!
Testing PDM conversion - Page 1
Forum section: electronics / projects

author: davegravy
author_rank: Regular Contributor
timestamp: May 14, 2022, 03:32:46 am
content: I have a MEMS microphone which outputs PDM and it's connected to an STM32U5. It's connected via the integrated Audio Digital Filter (ADF) peripheral which implements conversion from PDM including decimation and anti-aliasing filters. I'd like to input some test stimulus to the ADF to validate performance as I have it configured. For some of my testing I'd like to exclude the microphone part of the chain and test just the DSP. In other words, I don't want to be limited to acoustic stimulus.Is there a common practice way to do this?One idea I had was to replace the microphone with a 2nd MCU programmed to be a PDM generator. I could bit bang output the PDM data values on clock line edges.The PDM encoding algorithm looks simple enough to implementand I wouldn't need to store full test waveforms in memory since I expect all my test signals could be generated algorithmically (impulses, white noise, sinusoids, etc)Is there an easier option? I looked for an off-the-shelf device for this application but found nothing.
Testing scopes - Page 1
Forum section: electronics / projects

author: Sky_hawk
author_rank: Contributor
timestamp: April 08, 2012, 12:11:10 am
content: I'd like to test the rise/fall times on several of my scopes, what is a simple way to build a signal generator with for example a 10Mhz freq with very fast rise-times to serve as a signal source? Is it better to invest in a signal generator rather then to build one? any circuit suggestions?

author: grumpydoc
author_rank: Super Contributor
timestamp: April 08, 2012, 07:44:20 am
content: You need a pulse with <1nS rise times, there was a thread discussing this a while ago. You might also find thishttp://www.ko4bb.com/Manuals/09)_Misc_Test_Equipment/Novatech/Novatech_MTS529_Scope_Calibration_Source.pdfuseful.

author: bingo600
author_rank: Super Contributor
timestamp: April 08, 2012, 08:26:31 am
content: I'm sure i saw something in the Rigol DS1052E thread , where they build a "Fast risetime" generator./Bingo

author: saturation
author_rank: Super Contributor
timestamp: April 08, 2012, 03:41:36 pm
content: For low cost, available now there is a ~ $150 "100" MHz function generator discussed on eevblog, the Hantek 3x25, see the thread and mechatrommer's goltek software. It can give you the basic test signals for measurements.You can build the Jim Williams fast pulse generator.Both are discussed in the Rigol 1052e threads.Build or buy? depends on deals on eBay and if you can wait for a deal.The Jim Williams pulser will cost ~ $50-100 in parts, S&H included.I recently bought a Tek 284 70pS reference pulse generator for $100 and adjustable 10 MHz pulse generator for $25. I waited over a year for the right moment. Until then I used the Hantek as a test source.https://www.eevblog.com/forum/projects-designs-and-technical-stuff/generating-extremely-fast-rise-time-square-waves-for-probe-compensation/msg90410/#msg90410

author: free_electron
author_rank: Super Contributor
timestamp: April 08, 2012, 05:28:57 pm
content: the jim williams pulser works really well. there is also a chip from maxim that can create a very fast rise time.
Testing the resiliance of SP4020 and SP4021 diodes (and my function generator) - Page 1
Forum section: electronics / projects

author: bloguetronica
author_rank: Frequent Contributor
timestamp: June 30, 2019, 01:42:00 pm
content: Hi,This is more a curiosity than anything else. I've read about the USB Killer, which is a stupid way to test for ESD, as virtually any host gets destroyed. However, inspired by the way it works, I've decided to see if the SP4020 and the SP4021 diodes on the outputs of my function generator were resiliant.So, I've charged a 100uF, 35V electrolytic capacitor with 28V and discharged them both ways on each output. I was surprised to see that the TVS diodes did their job well, apparently not degrading the performance of the circuitry behind. Of course, this is not how an ESD test is performed, and a large enough capacitor with a low enough ESR would kill the outputs.This test is kind of a preamble to a project that I'm making. It is basically a USB2.0 connect/disconnect switch for testing purposes, with an integrated ammeter. I'm planning to use these diodes to protect the data lines of both upstream and downstream ports (there will be also a Polyzen protecting the power on the upstream port, and a large TVS diode on the power rail of the downstream port). They are not the typical TVS arrays that try to discharge ESD over the 5V rail, which is probably why many computers get killed by the shitty killer, instead of just the USB port. Yes, many 5V DC-DC converters that are used to supply the USB ports cant cope with spikes that are injected via the TVS arrays, especially if its internal Zener goes open, and the surrounding steering diodes survive.Anyway, you can see the schematic attached, and leave your opinion on how this device managed to survive, multiple times, and some times with visible sparks while "plugging" the charged capacitor into the connectors.Kind regards, Samuel Lourenço
testing tunnel diodes - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: November 18, 2021, 01:17:30 pm
content: Hi all,i need to test the tunnel diodes in my old tek scope,i know you cant test with a dmm,can anyone recomend a way to test them?,ie a schematic for a simple go/no go test jig,i have a scope and a sig gen,thanks in advance.

author: David Hess
author_rank: Super Contributor
timestamp: November 18, 2021, 05:54:06 pm
content: Use your function generator to apply a sine or triangle wave through a resistor to the tunnel diode, and look for the negative-resistance switching with your oscilloscope. Do not exceed the tunnel diode's voltage or current ratings.https://www.amplifier.cd/Test_Equipment/Tektronix/Tektronix_other/Tunnel_Diode-Pulser/Tunnel_Diode_Pulser.htmlhttps://w140.com/tekwiki/wiki/067-0681-01

author: coppercone2
author_rank: Super Contributor
timestamp: November 18, 2021, 05:59:41 pm
content: and FYI I did probe tunnel diodes with a DMM before (in my 3310B repair), the voltage drop is low, but they did not break from a 34401A probing them in circuit. Just saying so you don't freak out if you test it accidentally, its not guaranteed to break, but you should take special precautions if you are soldering with them, like goot brand heat sink clips and ESD protection IMO.To be honest I was not really comfortable or happy with the tunnel diode circuits until they were fully assembled back in their box, it s a pain in the ass to replace and people seem to have bad luck with them in general.
Testing UPS Battery How-To - Page 1
Forum section: electronics / projects

author: Wrydog
author_rank: Contributor
timestamp: August 15, 2018, 10:22:13 pm
content: I have several lead-acid APC ups battery modules that I want to check if they are still good. Their voltage is a nominal 192 V and they're a couple years old. What's the best way to test these to make sure they're still good?Thanks.

author: ogden
author_rank: Super Contributor
timestamp: August 15, 2018, 11:02:21 pm
content: Usually you measure battery pack using UPS itself - run battery runtime calibration and let UPS measure it's capacity. Advanced approach would be tomeasure impedance of individual pack batteries, assemble one best pack out of two, after that run UPS runtime calibration to measure battery pack.
Testing USB and Quad-SPI signal integrity after adding ferrite beads  - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: September 11, 2023, 10:06:05 pm
content: Hi,I added ferrites and CM chokes on the USB 2.0 data lines to reduce emissions. How can I check the USB 2.0 signal integrity so to be sure that the ferrite values will still allow full signal integrity (the product will go into full production so I need to check that)?What kind of equipment do I need and what tests do I need to make?I only have a 250MHz oscilloscope. Any chance of testing it with that or not? If not, what are my options?The same for a Compute Module high speed Quad-SPI. How can I check signal integrity for Quad-SPI?Thank you

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 11, 2023, 10:27:25 pm
content: I don't know what an EMC test costs, but you can buy a pretty decent spectrum analyzer for EUR1500.You can also buy mini Vector Network Analyzers starting from very low prices, and those also go upto 1.5GHz or so (more expensive is more betterer).I am not entirely sure of all the things you can do with those things, things like antenna efficiency and other things about the test setup can have a big influence. But you should be able to do some comparative tests at least. You have your "Golden standard" that failed EMC test by a certain margin (I assume you have test reports for that), and when you compare it on your bench with the "new improved" version you should be able to make a fair estimate as to how much better it performs.

author: spostma
author_rank: Regular Contributor
timestamp: September 13, 2023, 08:29:41 am
content: For USB, the poor man's solution is to find the maximum USB cable cable length that will still work well,both with and without the USB EMI filtering. The difference in maximum cable length can be attributed to the EMI filter.

author: Someone
author_rank: Super Contributor
timestamp: September 13, 2023, 08:55:44 am
content: Quote from: ricko_uk on September 11, 2023, 10:06:05 pmNo chance of full USB 2.0 compliance test with that. Plenty of documentation from the manufacturers about what is sufficient, or just hire a facility/specialist/test house that will already have it all setup and documented.

author: ricko_uk
author_rank: Super Contributor
timestamp: October 17, 2023, 10:51:13 pm
content: Hi,I did check the USB.org website but there aren't any listed in the UK.Can anybody suggest any UK-based test lab or some consultant who can do the testing and provide a report?Thank you
Testing with a DC Electronic Load Beyond its Limits - Page 1
Forum section: electronics / projects

author: enut11
author_rank: Super Contributor
timestamp: August 03, 2024, 04:27:08 am
content: I needed to test an Agilent E3612A power supply rated at 60v/0.5A/30W. My E-Load is rated at 30v/10A/150W so obviously the problem was with the voltage limit. I could, with difficulty, change the E-Load MOSFETs to higher rated devices but a much easier way is to use an external power resistor to manage the excess voltage.Simply insert a resistor of appropriate value and power rating in series between the DUT and E-Load.The external resistor is chosen so the E-Load never sees more than its rated voltage at the test current.Calculated resistanceRext = E/I = (60-30)/0.5 = 60 ohmsand power dissipatedPext = EI = 30x0.5 = 15 wattsSo, a resistor of 60 ohms/15 watts can be used, with my E-Load, to test the E3612A to 60v/0.5A. Such a resistor is shown below as multiple smaller power resistors (50+10) mounted on a fan cooled heat-sink.Careful setup and methodology is required to avoid excess voltage at the E-Load input terminals.1) Wire the external resistor between DUT+ and E-Load+ terminals2) Monitor the voltage drop across the external resistor with a DMM3) Initially, set the DUT output to the highest voltage limit of the E-Load (30v in this example)4) Adjust the E-Load to sink the test current (eg, 0.5A)5) Slowly increase the DUT output voltage to the test limit (eg, 60v)6) Disconnect the DUT outputfirstto prevent excess voltage at the E-LoadNOTE: The E-Load will always indicate the correct amps but the indicated voltage must be added to the external resistor voltage drop to calculate the correct DUT power.

author: enut11
author_rank: Super Contributor
timestamp: August 03, 2024, 07:21:02 am
content: Picture of the test setup.DMM indicates voltage across the (50+10) power resistors.E-Load shows voltage at its input terminals when the current is 0.5A(33.2v+26.76v)=59.96vPower supplied by the DUT (Agilent E3612A) = 59.96x0.5 = 29.98 watts, ie in spec

author: enut11
author_rank: Super Contributor
timestamp: August 03, 2024, 08:41:17 pm
content: The Agilent E3612A power supply has a high voltage range, up to 120v/0.25A, which I also want to test.This time we need to drop 90v before the E-Load so extra care needed here to avoid damage to equipment and personnel.Calculations for the external load:Rext = E/I = (120-30)/0.25 = 360 ohmsand power dissipatedPext = EI = 90x0.25 = 22.5 wattsThe setup and test procedure is similar to the first post:1) Wire the external resistor between DUT+ and E-Load+ terminals2) Monitor the voltage drop across the external resistor with a DMM3) Initially, set the DUT output to the highest voltage limit of the E-Load (30v in this example)4) Adjust the E-Load to sink the test current (eg, 0.25A)5) Slowly increase the DUT output voltage to the test limit (eg, 120v)6) Disconnect the DUT output first to prevent excess voltage at the E-LoadI don't have a suitable load resistor so ordered a 360 ohm 50 watt unit on eBay and will report results at a later date.
Texas instrument ads at top of page - Page 1
Forum section: electronics / projects

author: calexanian
author_rank: Super Contributor
timestamp: March 30, 2014, 04:35:58 am
content: My TI ads at the top of the forum pages is in Russian all of a sudden.. Strange much?

author: lapm
author_rank: Frequent Contributor
timestamp: March 30, 2014, 09:12:13 am
content: Is your data routed throw Russia suddenly? At work if i use network there all my data is routed throw Denmark, even if im living in Finland myself.

author: cravenhaven
author_rank: Contributor
timestamp: March 30, 2014, 10:20:54 am
content: I was wondering the same thing. I mean its fun to practice your ability (or otherwise) in other languages, but I wouldnt have thought TI were really interested in my education of anything but promotion of their product in my native language.

author: EEVblog
author_rank: Unknown
timestamp: March 30, 2014, 10:21:49 am
content: Weird, I don't see it, and no other reports.

author: zimzom
author_rank: Regular Contributor
timestamp: March 30, 2014, 10:28:23 am
content: I was getting Russian TI ads also. Thought it was my neighbors home-brew we had for lunch but it appears not.

author: madires
author_rank: Super Contributor
timestamp: March 30, 2014, 10:51:24 am
content: The geo-location went beserk. The German ads for MOSFETs are also quite funny. Instead of advertising a R_DS_ON of x milli-ohms they claim x Meg-ohms. Worst MOSFET ever :-)

author: Pillager
author_rank: Unknown
timestamp: March 30, 2014, 03:51:55 pm
content: Russian Ads as well. At least on my mobile internet connection. I haven't consciously looked at home.My location: Austria (NOT Australia)
Texas instruments application note - Page 1
Forum section: electronics / projects

author: Cicada
author_rank: Regular Contributor
timestamp: October 20, 2017, 11:06:22 am
content: HelloI am looking for this Texas Instruments application note. SLOA089, Circuit Board Layout Techniques. Excerpted from Op Amps for Everyone. Texas Instruments (2008) by Bruce CarterI cannot find it on the texas instruments website or on the web. I struggle with the Texas site to search for appnotes.All the datasheet that refer to this app note have the linkwww.ti.com/lit/pdf/sloa089which does not work even if you add .pdf behind it.Maybe some have it on their PC.Thanks

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 20, 2017, 11:25:25 am
content: archive.org is your friend:https://web.archive.org/web/20120324065448/http://www.ti.com/lit/ml/sloa089/sloa089.pdf

author: danadak
author_rank: Super Contributor
timestamp: October 20, 2017, 04:49:06 pm
content: More ap notes on PCB layout -https://1drv.ms/f/s!Al2JgiX7_qf0iyDXnGfeprN62OJPRegards, Dana.
Texas Instruments notation question - Page 1
Forum section: electronics / projects

author: BurnedResistor
author_rank: Regular Contributor
timestamp: November 18, 2016, 09:29:59 am
content: Dear All,I am working on designing an amplifier to alllow for the scaling in the for of y = mx-b, and found a TI reference manual:s"http://www.ti.com/lit/an/sloa030a/sloa030a.pdfHowever, in the appropriate section, on pg12 the book uses a notation that I have never seen before in Analog design: R1 || R2I am guessing that this is not a logical bitwise operation?I was not able to find out what this notation meant :/ Anyone got any ideas?

author: BurnedResistor
author_rank: Regular Contributor
timestamp: November 18, 2016, 09:32:18 am
content: Similarly they stateR1 || R2 << RgAgain i really dont think the << is a bitwise shift. Anyone know?

author: Phoenix
author_rank: Frequent Contributor
timestamp: November 18, 2016, 09:40:12 am
content: || means in parallel<< significantly less than (orders of magnitude)>> significantly greater than (orders of magnitude)

author: BurnedResistor
author_rank: Regular Contributor
timestamp: November 18, 2016, 10:02:21 am
content: Oh wow thats pretty neat!In other words, R1 || R2 << R3R1 and R2 in parrallell are 2 orders of magnitude smaller than R3?

author: dmills
author_rank: Super Contributor
timestamp: November 18, 2016, 10:19:16 am
content: I don't think << necessarily means TWO orders of magnitude so much as the less precise "LHS Much smaller then", how much smaller depends on how close you need the approximation to be.It could be 1, 2,or 3 orders, but is it uncritical as long as R3 is a lot bigger.I would note that there may be other constraints, so don't get silly, output drive, input bias current, thermal noise.... But the simplification in the maths works as long as R3 is much bigger then R1 || R2.73 Dan.