ESR meter upgrades

[eccerr0r]

Re: ESR meter upgrades

Fail. Autotransformers show up as two resistors...

[eccerr0r]

Re: ESR meter upgrades

I figured as much (need to lose one of the pins), but by doing this (shorting pins), isolation is lost

So does it actually detect an artificially "broken" "optoisolator" in this way? Tell a triac or scr or bjt or photoresistor or photovoltaic or photodiode or other type of optoisolator?

Incidentally, can it detect autotransformers? heh, probably shows up as a 3 pin short, but then again an inductor shows up as a 2 pin short.

[stj]

Re: ESR meter upgrades

actually - you can test opto's with an adapter

[eccerr0r]

Re: ESR meter upgrades

More fun with avr transistortester:

Plugging in a 4N35 ... detects as a transistor.

That's fine, now test 3 pins on a side at a time...

one side shows up as a transistor. Good.
other side shows up as a diode. Excellent.

Too bad ...can't tell if it's working... or can it... I wonder what it would do if I connected the diode's cathode to the emitter, and connected those to pin 1. Connect the diode's anode to pin 2, and the collector of the transistor to pin 3... what would transistortester report this as...

[stj]

Re: ESR meter upgrades

but you dont have a wiring / loom schematic if the customer just brings the board.
i dont want slot machines delivered just to fix a control pcb

besides, you often spot parts that are "almost" failed so you can pre-emptivly prevent the board coming back a week later

[eccerr0r]

Re: ESR meter upgrades

but still, you have a bank of solenoids, and one solenoid isn't working...well, something be a bad one on that circuit... (and then the TRIAC the AVRTransistortest pukes on...)

[stj]

Re: ESR meter upgrades

not so easy though when they are fired with short pulses and drive triac gates.
(solenoid drivers)

[eccerr0r]

Re: ESR meter upgrades

would expect digitally used transistors to be fairly easy to check for operation... it's either on or off, if it doesn't turn it on completely, it's bad....

[stj]

Re: ESR meter upgrades

your not working on digital stuff then.

i recently pulled 16 transistors that powered solenoids,
didnt know the spec so just compared them to find the odd one(s) out.

[eccerr0r]

Re: ESR meter upgrades

Perhaps my issue is that I don't remove things until I'm sure something's dead... But once I find components are dead in circuit I don't need to test it again out of circuit. I guess that's why I'm not finding it as helpful as some people are.

[stj]

Re: ESR meter upgrades

i use it a lot to check transistors for shit my multimeter diode check would miss,
like bad hfe or an internal diode

[jondoe]

Re: ESR meter upgrades

I used mine the other day to confirm a suspicion that the mains filter caps on a device weren't performing as they should. Sure enough the test showed they were 50% of their rated value, I swapped them out, all was good after that.

[eccerr0r]

Re: ESR meter upgrades

Just wondering... Ever since I got this AVRTransistorTester it's pretty much stayed in my "toy" pile and have yet to actually find a bad transistor or other device that I already knew of its status of good or bad from other tools or debugging techniques... Has anyone felt the same way? Or perhaps my source of parts that need testing past basic debug techniques is low... Plus the false positives (like the thyristors that can't be triggered)...

Granted this thing does tell me a lot more of any device I stick into it than any other tool that I've used for any particular device that it supports.

Yes this sorta sounds like parade raining but just wonder how other people feel... do they use it a lot? Has it saved you effort? How so?

[eccerr0r]

Re: ESR meter upgrades

Start paralleling them up

hmm... need to see some others between 0.22F and 0.047F. 0.01F worked just fine too.

---

Tried 0.04F/50V capacitor - reads as 52mF 0.13Ω ESR 1.9% loss... I guess that's acceptable and within 25%...
Added a 0.015F capacitor in parallel to the 0.04F... read 71.66mF -- 31% error.
Added a 0.0165F capacitor in parallel to the 0.15F and 0.04F... read 92mF, that's a 29% error.

[stj]

Re: ESR meter upgrades

largest cap i have tried was 22,000 uf - it read just fine.
i doubt i'll ever find anything bigger than that.

[eccerr0r]

Re: ESR meter upgrades

lol yeah that's not very good... ever tried regular capacitors that big? I haven't tried anything beyond this 0.047F yet... need to see what it does with 0.22F and 0.3F that I think I have...

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Just tried 0.22F - it gave up, no or unsupported device.

BTW seems that having big caps inserted on power up really slows down the power on auto self-cal it seems haha.

[stj]

Re: ESR meter upgrades

one gave me 84uf, the other just gave a resistance!

[eccerr0r]

Re: ESR meter upgrades

I charged up this supercap to 3.6V for a couple seconds, well it indeed can light an LED with a 1K resistor for quite a while. After discharging it for several seconds through that LED (disconnected before it was flat - it was 2.4V), it was still able to light a 1W LED through a joule thief for a bit more than half a second before it went flat. So this supercap sort of works...

What kind of readings did you get?

Oh, after a charge/discharge cycle transistortester read 23mF... a bit higher but still lower than expected.

[stj]

Re: ESR meter upgrades

o.k. i tried a couple of .47 at 5v ones.
dont work
both gave different readings so they could be fucked - but i dont think so.
they do have limited charge/discharge cycles though.

[eccerr0r]

Re: ESR meter upgrades

The 0.047uF supercap is rated at 5.5V. Checking its voltage when charged up, yes this thing seems to leak fast when charged to 3.6V so it may be bad, but it settles down to 3.2v and stops leaking down as quickly... Not sure what to make of it.

A capacitor of sufficient capacity may well be called a "cell"... does it actually detect batteries? Seems like a dangerous thing to hook up for the longevity of the device...