Convert Your MULTIMETER into an accurate SHORT CIRCUIT TRACER Finder for less than $1 Build This DIY
LER #204 Want a powerful easy to use Short Circuit Tracer but can't afford the price tag? Here is how to convert a multimeter into a powerful and accurate short circuit locator for less than $1!
Review: Vici 480C+ vs YR 2050 MicroOhm meters / short circuit tracers
• MicroOhm Meter Short C...
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TEST METERS
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BENCH PSU
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SOLDERING
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Richard
So to determine the constant current you must divide 1.25v (Vref for the LM 317) by the desired current to determine the resistor value. I would choose 12.5 ohms exactly (15||75) then I know the circuit is producing exactly 100 mA. Then, the millivolt reading on the DMM can be multiplied by 10x to know how many milliohms the resistance is between the probe tips. This would be much more of the usage in my case. The nice thing is the circuit only uses the battery during test. Thanks for the idea. UPDATE: I did this 4-wire circuit using the LM317 externally and it worked really well. Then I noticed one of my super cheapo multimeters has lots of room inside behind the think COB board. I proceeded to take apart a single cell power bank device then install the charger chip and the flat 800 mAh lithium battery inside the DMM, adding a hole in the side for the charger USB access and replacing the USB out connector with wires to the LM317. Also added a small light pipe to see the LED status lights for charging. I enhanced the constant current circuit described above even further with a 0.1uF cap on the input to reduce noise and a 47uF cap on the output for stability as I saw elsewhere, mounted this on a perf board. To finalize, I added a wire soldered rapidly very close to the tip of each lead, ran the lead down the side of the regular probe, and heat shrunk them along the pen grip. I also heat shrunk each current wire to the main probe wire with a 1 cm piece every so often to keep them manageable yet flexible. I would never use the 10A jack on this meter so I removed the terminal and ran these two wires into that, with a 2P connector to remove the leads. Now I have a modern portable rechargeable micro ohmmeter! If the 2P connector is detached, I can continue to use the remainder of the DMM features off the still-installed 9V battery.
You should repeat this on camera for us to watch. Full credit given of course. Don't worry about production values. This guy obviously doesn't.
Excellent additional info , well detailed, a very big thank you for your kind input, modern day platforms gives everyone an insider view to share and discuss better innovations. a few kind appreciative words can also go a long way as feedback to the effort expended, as the old saying goes; No good deed ever goes unnoticed, Thank you 🙂
Good read I have a cheaper meter I. Might do that with
I am so glad that you covered (in the second video on this subject) the information about not using PSUs for your power supply, because they have capacitors inside them. I would have surely missed this point. Meaning, I would have included the capacitors that the data sheet suggests to stabilize the operations of the LM317. Including those capacitors would have created a monster. It is very likely that it would have never occurred to me what the problem would have been.
I quite often just set the supply to 500mV and CC=100mA, connect probes with clips so you dont have to hold them, then quick calc the wattage, and determine if I need more current or not to slightly heat up the short (EG: 100mW is not a lot of heat). With the back of my finger (its a lot more sensitive), I feel around for the warm spot, if i cant find it, I turn the current to 200mA and repeat. If its a serious dead short, there is almost no wattage to heat up the short, and you need more current. If you find the area but not the component, rub a little rubbing alcohol on it and watch the first place it evaporates = short, been doing this 1982, good luck.
Ozzy33333333 Yeah I also use this technique in several of my videos. The rear of my little finger is able to tell temperature differences within a couple of degrees C Your method will not always work though, as this video proved! I tried everything, including maxing out my 5A bench PSU and in the end had to resort to more drastic measured to find the short!! kzhead.info/sun/iL6OpJRrpXZvqmg/bejne.html
The lips are the most temperature sensitive part of the human body. If you really need to find that short, better get kissing!
3t
@@Scrogan haha
I had recently a quite odd short circuit. It was not between power and ground. It was on, and off kind one, indirectly between +15V and +24 V rails on a large PCB. That was a reasonable conclusion, as the 15 V supply voltage rose to 17 V and there was no other source to cause the climb than the +24 V. At the "far end" of the 24 V trace, there was a resistor that had (24 - 17 ) = 7 V drop at the times of the trouble. So, what was touching? I spent time with a 4-wire ohms of a bench supply, to no firm conclusion. Eventually I decided to dig out my decades old HP probes, 546 pulser and 547 current tracer. I sent pulses to the end of the found resistor and the pulser probe return to the +15 V bus. No 24 V or 15 V applied, just my pulser. then I started following with the current tracer probe the line from the the resistor and checked all the branches, changing the pulser return attachment point, until there was nothing detected further along the trace. That point still did not appear to immediately explain the short. However, touching the wire wound resistor connected and disconnected the path. The resistor was one of Ohmite enameled resistors, where the connecting leads were welded to tabs on one side of the resistor body and ran parallel to the resistor. Turned out, one tab was directly above the trace I had followed. And it had rubbed through the solder mask. The resistor had been mounted with the tabs touching the solder mask and the soldering probably caused thermal shrinkage and the punching. Bending the resistor leads up to create a gap between the tab and the board surface fixed the problem. As a distant memory, I have twice met another kind of short that was just between two parallel signal traces. In those cases there was nothing visible anywhere along those traces, and in those days we did not even have solder mask on our boards. And I did not have my HP tracer probes yet. But without the solder mask, following the traces was easy with Kelvin probes. When the short appeared at an unexpected position, I had to see what was going on. I chose to use my Dremel and started gradually grinding the epoxy board between the traces at the location indicated by the resistance measurements. In no time, I got to copper, buried inside the glass fiber epoxy material. It was just a tiny sliver, evidently buried already during the original laminate prep operation and having escaped the later etching.
Very good explanation on how to get better low ohms accuracy on your meter. Never thought of that. Its so simple it even hurts ... Your channel really needs a lot more attention from viewers.
Best thing I found is a “audible milliohm meter” like the EDS “ leak seeker” ..... seriously look it up if you haven’t seen one. It’s basically an extremely fast and accurate low ohms meter that SINGS. It plays a different pitch as the resistance changes, even the tiniest changes in resistance. Like the difference in 1 mm of copper trace. allowing you to track down shorts like nothing else you’ve ever seen. And I’ve got a metrology business doing test equipment repair and calibration… So I’ve got all the professional expensive benchtop gear… But I swear to God I grab for the EDS devices every day. Not only the leak seeker but also the cap analyzer. Not affiliated with them at all, I’ve only talked to Dave the designer once or twice. Nothing to gain or lose and don’t give a shit if anyone checks it out… I’m recommending it only because of how much it’s helped me and countless others. Like everything, it takes a bit of practice to get used to it. I like to compare it to a high-end Metal Detector or something like that… You can’t just spend a ton of money and expect it to work and interface with your brain instantly. Or like professional engraving equipment used by jewelers and Gunsmith. Or a fancy tattoo gun or something like that .....You can spend a few thousand dollars on an engraving machine… But you still have to learn to use it and practice. But with a little bit of practice it will be One of the most useful tools in your arsenal.
I took your advice and looked this up. Wow, I'm going to grab one of those. It's like a precise version of the thermal camera trick of narrowing down an area with a short. The sensetivity is incredible.
Keeping it simple…love this kind of approach to trouble shooting. Gets my brain more engaged! Well done mate. Darrell - 🇨🇦
lol, seems by the time your finish you may have found the fault but now youve got a hell of a headache.
That is a very neat way, I haven’t thought of to test resistance, but makes complete sense, as an at home amateur fixing my own things
Brilliant video as always, love these kinds of (hacks) that make expensive tools available to the hobbyist.
Hello, I’m still a novice at electronics, so some of the stuff in this video went right over my head. But it was still, so interesting to me, that just had to subscribe to your channel, straight away. I’ve always found shorts, hard to find and this build of yours seems so simple and accurate. Additionally, believe I have the components to build this device, so I will have a go at it. Thank you immensely
You have well-earned my subscription. I have a board with about 100 74HC00 series ICs on it, and the 5 Volt power rail has a dead short on it. I thought it was not even worth the trouble to cut PCB tracks to try to isolate the fault, but you, sir, may just have saved the day. 😁
Connect it to a PSU with say a 1V output and constant current set to 1 amp and you will soon find that shorted IC
A thousand thank yous for demonstrating this sir. It definitely helps a lot of amateurs like me.
Any thank you very much for your video about finding short in circuit because I am not E engineer but now can repair many things learning from yours. Thanks again.
I'm still cautious with the voltage. When I'm tracking down a short on a higher impedance signal, like an IO line, I still like to be careful the level of input voltage I'm using to drive the current source. If the short somehow opens while measuring, or I accidently probe the wrong net, I don't want to put 5V into a node that's only designed to take, say, 2.5V or 3.6V max. You're correct that in most cases, ICs will have a reverse diode in the silicon that will safely backfeed the current out to whatever internal VCC is used, and the low amperage won't be enough to hurt it - but, some devices are very sensitive. What I do is use an external bench supply rather than something like the LM317, and I'll set the voltage to 1V, or whatever the rated voltage of the shorted line is ... or lower if other signals nearby are lower level - I've never gone lower than 1V though. Then, I'll short the leads on the power supply and adjust the C.C. mode to the constant current that I want before I start measuring, then I "Kelvin" around the board with the highest resolution multimeter I have on hand. On large or complex boards, sometimes shorts are still difficult to narrow down, and when desperate, I've cranked the current up high enough into the shorted net that I could "feel" around the board for the warm component. (Not too high or you might burn you finger or melt a trace). It doesn't need to be a ton of current these days if you have a sensitive thermal camera. If anyone tries the higher current 'heat' method, I recommend that you keep the supply voltage lower in case the short opens or you probe the wrong spot. Good video!
One issue with CC your bench supply is, quite often there is a cap after the CC circuit, there is on all my $1600 and up HP lab supplies at work, like 470uF or even 1000uF, this charges to the Vout voltage, then when the probes connect to the boards short, it then sends a hell of a current spike, so simply use a inline current limiting resistor.
@@Ozzy3333333 Yeah, if you're concerned about the brief current spike, using a resistor in series with the supply output isn't a bad idea.
Yeap, Im more inclined to use an external bench supply unless i really know what im probing. For capacitors is fine, but for more sensitive components, you have to be careful about the voltage used. I do find this method intriguing though. The readings he found were not overly convincing until he really hit the shorted spot. I guess I could work a diagnostic method using this principle, but does this mean that I would still have to probe each component individually? While I am not against working each component individually, Alcohol, Freeze, and Thermal Imaging do provide better pinpoint accuracy. It is perhaps my unfamiliarity with this process that I do not readily see any significant difference on the shorted capacitor column in question.
@@Ozzy3333333 hmm, thank you for this. Does those chineese, so called "short killer" voltage injectors have that in mind in design?
You've build your own Kelvin clips. I've used the technique in a commercial armature testing machine with resolution of around 1 microohm. You can also use the technique to eliminate the metal junction voltages by either reversing the current or voltage probe polarity and resolve the unwanted junction voltages algebraically. Also, in automotive simple stuff, just use an incandescent bulb in series to regulate the current.
Greetings sir. I would like to thank you and commend you for the great work you do. the way you present the content makes it very easy to understand concepts that were difficult for me in school. Be blessed and all the best in all your work.
I was looking for this kind of info about multimeter's voltage dropout measurement fundamentals. But had no luck, now this video have suddenly popup on my timeline. 😁. Brilliant.. Thanks...... Subscribed.. ✌️
Richard, I saw this title and was thinking if you will build a oscillator/freq . generator and build yet another ESR meter :) Loved your ESR video ( All You Need To Know About ESR METER To Fix Stuff. How To Use Test Capacitors Inductors Short Finder ). Keep up the good work. Today I also fixed some mainboards and GPUs. Always interesting seeing other guys with the same hobbies/passion for the same things.
There are all sorts of ways to quickly find a SC component but this is a good one. Another old school way is to connect your bench supply on current limit for a decent but not damaging current, then dust a blast of freezer to the board. after a few seconds the white frost will melt on the hot components designating the thinnest parts of the current path including the short component which will thaw before the other parts.
Thank you I guess you also watched this video for more short finding methods? kzhead.info/sun/irGhoK-KcKptf58/bejne.html
Very cool, I use a thermal cam to find shorts but I will definitely build this to see how well it works.
Thanks for sharing this with us, Richard!
I’ve done this before, but I used minigrabber clips to attach to the multimeter probe tips. I like the wire terminal solution, though! My minigrabbers would often pop off my probes if I moved them around too much
Thank you for making this 2-part video tutorial. I have built my own based on your design and it works remarkably well. The Aneng meter is a little hidden gem too!
This is a very informative video! I made some modification: 30VDC supply and dropped the current to 10mA. I can trace shorts and test LEDs and zener diodes
I've seen few videos of diy milliohm meter and this one is the most simple and easy to do i got an lm317t from an old dvb receiver and a 21ohm resistor, i will simulate a short circuit on capacitors in parallel and see what i get from my 3 digit dmm. Thank you for sharing this i appreciate
Just to be sure to connect the output from pin 1 of the LM317T. I made a mistake later in the video and showed the output on pin 3. Also make sure to set your multimeter to millivolts range. You meter should have a resolution of 200 micro ohms with this short finder modification
@@LearnElectronicsRepair Everything's in the right place ready for tomorrow's test lol Thanks again
Incredibly valuable to me !!!. Thanks for another amazing video !! Mil gracias 😉
This is a very neat economical idea. There is one thing that reduces its usability: the way the connection is made means that you include any contact resistance between the probe and the circuit track in the measurement. Much better consistency can be gained by making separate connections to the PCB for the meter and the current source - i.e. two separate sets of probes, one for the meter and one for the current source. You could do this with double-pointed probes or just solder the current source leads to the board somewhere across the tracks that are shorted and then probe with the meter. Regarding the over-voltage worry, you could place a silicon diode across the current source - this will limit the output voltage to about 0.6V.
Spring loaded Pogo pins are perfect for that purpose.
Yeah, brilliant idea shown in this video. Another thing to watch with probes is regarding their condition: if you have old worn probe-tips that are tarnished, you will get inconsistent readings. Replace your probes if this happens. Also, when probing at a solder joint, always remember to push and wiggle your probe as you make contact with the solder. This helps the probe tip to pierce through any oxide or flux layers present on top of the solder. Very fine (or needle-tipped) probes are ideal for this. You could also use the NULL function on your DMM to subtract the resistance of your probe wires. When probing for shorts, anything that results in better readings is always welcome!
Excellent !!! The way the supply wires are hooked-up is the best way to eliminate lead resistance. One may also solder the LM317 wire and the black lead on the terminal block before screwing it to the probe. Little suggestion here: Add a forward biased diode (with wires) between the leads. This diode will limit the inter-lead voltage to 0.7 volts. Also, the LM317 may be installed next to the 4.5V power supply, along with the diode.
Hi Richard, love the video and the project. Could you use the explanation ending at 6:00 to infer that the short is wherever the meter is reading HIGHER precisely because of the described effect with the cables and the voltage drop? Keep up the great content and thank you again for the amazing wealth of information contained in your videos!
This is brilliant...I already have every components with me now....thank you sir...
Thanks you. Get it built, test it and let us all know how well it works for you 😁
that was awesome, keep up the great work brother.
Thank you so much Greetings from north Africa (Algerian dezert)
Thank you, God bless your hands, thank you thank for sharing thank you from Syria ❤🙏
Sir thank you so much for sharing your skills Watching from Ship.
Funny , using same circuit with just little difer. resistor as miliohm metter which working flawlessly but never ever came on idea to use it this way. lol . Thank you very much !
Very clever Richard. I enjoyed your explanations.
Nice little hack Richard, awesome idea and upload 🙂
The thing is when you have a large circuit it can take a long time checking every permutation to home in on the likely fault. In very low power circuits it may be your only realistic option but where there is a bit more current flowing I'd use the tried an tested method of putting your fingers on the board - it is surprising how hot shorted or partially shorted components can get. I do like your idea - a bit of heat shrink on the probes to tidy it up and I think we have a useful tool which has its place in our kit for fault finding - and at a reasonable cost !
Yesterday, I used my fingers to find a 555 shorted via reverse polarity.
@@garydirkse9900 You can also use rubbing alcohol. It is very flammable so be careful. If you have the general hot area then dab it on with a cotton bud. You see some people spraying it on a PCB but I wouldn't do that it's just too risky. Putting IC's in back to front is usually a great way to get them hot. The alcohol is so volatile it can start to evaporate at fairly low heat levels.
First time watched one your videos. That is so impressive and even better because quite simple
Cheers
6:41 For curious ones, this principle is also called 4 wire measurement. In combination with high voltage testing, 3-6 kV with low current, purpose is to test cable harness used in battery powered cars. In that way you can detect damaged cable, which will start fire in car.
Yeah Kelvin Probe = 4 Wire Measurement. Glad you enjoyed it and thanks for the info 🙂
Why would you need 4-wire resistance measurement if you're using high voltage and low current? Might you be getting confused with "Hipot" testnig?
@@Graham_Wideman We actually use two devices in one system, Schleich HV-GLP1 and RESISTOMAT 2316. This is industrial and research grade equipment. I tried to avoid confusing people, by going deep in details.
@@orion310591RS Thanks for your reply. So judging by your test equipment, the Resistomat tests cable end-to-end continuity using 4-wire measurement, which parallels the topic of the video, and for which high voltage and low current is irrelevant (which was the point of my question). Your HV-GLP1 tests high-voltage leakage between conductors, which does indeed involve high voltage and detection of low current, but is completely unrelated to the video we are commenting on.
@@Graham_Wideman Lets just say I am not allowed to explain details of machine publicly. Sorry. Parts/devices are public, but details are just not meant to be public.
This channel is gold!
Excellent video, I am having trouble finding a short, in my Ford focus, this video will hep me find it.
Well that was pretty slick, you gave a cheap some Valium you install the capacitance test, and I like the way you done yours better than way mine does, I'm saving your video and doing the same thing you have done thank you sir
Also, not sure if you folks are familiar with the device called the “half ohm” available online pretty cheap. And other multimeter adapters that you can build cheap or free. There are many videos on KZhead about these milli-ohm adapters, I’ve tried several variations and they’re all pretty decent. Especially if you use one of the cheap sets of kelvin clips/silicone leads available on eBay and other places in China. Don’t get me wrong, I love my fancy benchtop equipment, with their various leads and fixtures, all beautifully and painstakingly designed… But you can spend several hundred dollars very easily on a simple set of Agilent/keysight text leads. And unless you’re doing this work every day and offering it as a service like I am, it’s pretty much ridiculous and not needed. And you can get by with some thing that is incredibly affordable. With a precision that will surprise you! It really is the golden age for electronics… And Especially test equipment.
This is a great idea 💡... Thanks for sharing this...
Супер. Все гениальное просто Браво Спасибо. Like👍
I don’t have a bench power supply, but to understand correctly I could simply take a phone charger, strip the USB connector, and link the hot/ground wires from the charger to the red and black wires which would otherwise be going to the psu? Thank you Richard for this awesome video!
Love it thanks for the idea 💡.
OOOoh we got the same Fluke multimeter the 79 series II. How cool it is to see that. SUPER workhorse I trusted my life to for a couple decades (alongside a pressure-type amprobe clamp meter and an old Triplett 630 NA.). I grew to distrust even the Fluke name one time when doing wound rotor T-lead current draw readings with my Fluke 79 and a plug in Fluke 1000VAC / 600VDC amp clamp. I was suppoda set me Fluke meter to millivolts range. Turned on the powered FLUKE Amp Clamp...and I had a floating reading error that was unacceptable. problem was at the probe sockets. Snake oil salesmen. Smoke and mirrors. fancy business. Can't trust my life to this crap. So I fell back on my GRANDFATHER'S old Triplett 630 NA and bakelite Amprobe amp clamp meter. So long as I wasn't doing amp readings in the field on 300HP wound rotor 3 phase 480VAC motors I was fine. But that was my life. I fixed contactor contactor logic controls and resistor banks on huge class F hot pot steel mill melt bay cranes for a living. The Fluke - I could carry anywhere, beat it around, not worry about it, take it to hell and back with me and trust it...with caveats. For every job: there is a tool. A one. right. Tool.
Thank you, this is genius. Earned yourself a sub my friend!
Love it, will sure try this out :)
According to the TI datasheet, the current with that cct is 1.2/R , so 24 Ohms (which is a standard E24 value) would give you 50mA cc output.
Datasheet also states that the device will source current necessary to maintain a 1.25V higher on the OUTPUT than the ADJUST terminal. The correct formula to calculate the current would be 1.25/R
Hello. I've seen some videos from other channels. And all of them, use the LM317, with little variation at schematics. I like the idea of using a battery from an old phone to do portable and rechargeable. But that is 3.7V nominal, so I've considered use an 7833 (3.3V lineal voltage regulator). It's a good idea, Or maybe for this type of circuit, it's better to use the LM317? Thanks!
Great,I like the probe connectors. An infrared camera is way faster and easier, and pricier.
very nice Great vid Love it Thanks for Sharing
Thank you so much rich. You save my money
Great idea and well executed, however some meters have a delta function which can be used to offset out the leads to give a true zero reading. It's a function that many users often don't realise they have, seeing the triangle symbol doesn't give it away (unless you've read the book..lol)
Exactly, all multi's dont work the same and compensate for the very very low resistance of the leads, I also do not agree its an unseen resistor at the lead tips until they come in contact with a conductor of some kind.
Fantastic video quick question would a 100ohm resistor work better I’m asking because I’ve already got these resistors in stock
Thanks for sharing... I will try it ... 👍 Thanks ...
Your very resourceful. That was cool 😎🙂
Wow, excellent explanation. Thanks.
One word.........amazing.
A most excellent and interesting DIY Short Circuit Tracer. 🥰 Also there is unit that varies the audio tone as the probes gets closer to the short. I think they are pricy? 😎 Thank you.
This makes me want a 3d printer Right Now because I have notions of a custom probe with a swivel switch to change the resistance on the fly similar to a cars windshield wiper speed control.
Best thing I ever bought was my 3d printer come in handy for all kinds of things and saved me money.
Impressively simple, Why I'd not thought of this.... Well, now I know a mod to do on the multimeter I have at work. Though, the current-source, does this have to be as close as possible to probes? I'd thought, one set of probes to supply a constant-current and another to read the voltage and thus as long as the cable resistance is kept in mind, all should be good?
In each case, I would've scraped the probe ends together to compare its reading to to that of the circuit under test. It's how I'm able to zero (by pressing a zero button) my cheapo ESR Low ohms meter before probing.
I really appreciate the information that your videos demonstrate. There is just one little thing that I have problems with and that is seeing clearly when you do pen and ink drawing. Now I am long in the tooth and probably do not have the best monitor. I am however able to see the drawings done with other pens, If you look at "Great Scott" I can see his clearly. I have had this problem on other videos for example "The electronics School" So please do not think that this is a critic of your show, just something I think may help some of your audience.
Could also use an old USB power bank to provide the '5V' from a u/s usb-lead; easy disconnect!, easy recharge. Neat trick.
Cracking little hack 👏👏👏😊
Just discovered this chan. in video suggestion feed. You've got another subscriber. Brilliant video!
Very clever and useful.
Sir Great and knowledgeable video ,sir do have any in detailed video on how the UPS work and how to repair the UPS
With the lockdowns, I neglected to maintain my Fluke and corrosion form the battery rendered it unreliable for use. I now have an ANENG 618C. None of the shope dealt with Kaiweets and even their contact refused to respond to my email. Anyway I use the millivolt function to get a figure of merit for my car electrical system. Two wires from my car battery act as fuses. By measuring the millivolt drop across the fuses, I can see which direction the current is going and an indicator of the magnitude. One fuse leads to the various fuses and loads and one fuse leads to the alternator. If you keep records, you can determine any deterioration of the alternator/bushes.
Do you have a Hakko 301? I have a couple other different kind and they get stuck and gotta use that thing to clean out the Point of the heater. you might be able to get a Hakko301. One for around about $210. This one is the update. From off eBay maybe? Boy have I been watching you watching you and watching you! I can’t wait to see you in the land of the living. thank you thank you.
You can buy leads that already have a known load on them that will perform this function already!...........
Are they as cheap as an LM317 and a 22 ohm resistor?
Place a silicon diode in parallel with the resistor. Doing so will set a voltage of around .55V to .65V across the resistor and should prevent over voltage to sensitive components.
I like the idea, but to protect the circuit a bit for when there is no short, I'd put a diode (or two) to ground on the output of the regulator to limit the voltage delivered to 0.6v (or 1.2v) incase some of the other parts on the board don't want 5v fed into them in a powered down state.
I rely on my ancient bakelite bridge megger for shorts on my car and Vespa or around the house, abs brilliant as you can guesstimate how far along a line a short is and move the insulation clamp closer and closer to the break point, got a little windy handle to send 120v down the line and despite its age is super accurate... just a shame its too unwieldy to use in small electronic scenarios so I have to use the ol isopropyl alcohol thingy and inject small amounts of voltage around the place as thermal cameras are very expensive.
Why not use an LCR Meter? No good in circuit? Thanks for the brilliant videos
I used something like that once to test microswitches. I epoxied a Berg connector to my 3v torch and added a resistor. The dodgy ones were above 6mV across closed contacts. I opened them up but could not find any obvious corrosion. You missed an opportunity to short out your lead tips - I am curious what reading you would get. Maybe I fell asleep at that point.
Thank You!
Heya that's a nice easy solusion love it
amazing tracer
Thx u thx u God bless u don't stop teaching us and thx u again..... Can u do one on a obd 2 j2534 how to build our own etc.....thxs
I've tested it on my 3digits dmm on 200mV i simulated a short on one cap from 3 in parallel the shorted cap shows 0.1 the other caps that are not short show 0.2 however it takes like 5 second to show 0.1 on the shorted one sometimes more seconds when i simulated two shorted caps and sometimes you must probe a bit harder on the caps legs to get a good contact otherwise it won't show the right reading so be patient if you have a dmm with only 3digits it's good that you've shown the fluke compared to the aneng despite having both 4digits display but the aneng has more resolution
Great video, Thanks! Do you think AMS1117 1.2V could be a good alternative?
Thank you
Fantastic project to help with diagnostics.Constant current generator ?
Best 19 minute nap I’ve had in a long time…
Haha - subscribe for more fun LOL
Brilliant
I understood that the lower the drop voltage the most pobable to have short circuit in the specific component. I also understood that the circuit drops the voltage in order to limit the current to 50mA (correct?). But can we claim that the actual resistance is 0.175 mv / 50mA ? Very educative video. Congratulations and thanks a lot.
A very interesting setup. I have to try it. Having a precise adjustable power supply with CC mode, I'm guessing it can be used directly attached to the multimeter tips to work in the same way. Am I wrong?
Yes any CC supply would work in the same way - but I have seen bench PSU not work very well with low CC settings - try setting your bench supply to 12V 10mA - then connect it directly to an LED. if the PSU can limit the current to 10mA before the LED blows, then it is good for this purpose. If not (as I suspect), just use a 10 cents LM317 like I did 😉
Thanks
I wonder if it could be calibrated to read out say .1 ohms or .2 ohms ? I have a circuit called the go no-go continuity and leakage detector and I have the circuit but I don't know if the IC is actually a constant current regulator in fact. It uses some opto isolators also, quite different.
Hi boss, do you sell a DVD or thumb drive with all your videos on it? Cheers Mark
It wants a couple of diodes in series across the output to keep the output voltage low so your not going to turn fets on etc
Correct me if I'm wrong but there's a rel button on the attic 8008 which rels out the or cancels out the resistance in the leads
Very good!
very cool idea 🤘🤘
good idea