esr or cap tester

[tibimakai]

Re: esr or cap tester

I assume that, is that fairly large square diode close to the leads. That one checked out good.
Thank you for the link.

[Behemot]

Re: esr or cap tester

http://en.wikipedia.org/wiki/Transil

[tibimakai]

Re: esr or cap tester

What is a transil?

[mmartell]

Re: esr or cap tester

Oops sorry I didn't realize yours was dead.

[Behemot]

Re: esr or cap tester

Cold joint maybe? Also check the transil, it's there to protect the device from charged capacitors.

[tibimakai]

Re: esr or cap tester

I have measured it and it's fine.
I have started measuring other components and while I was measuring one of the transistors, I have just heard the startup beep.
Not sure what happened, but it's working now.

[mmartell]

Re: esr or cap tester

Yes check the one ohm resistor - it is between where the test leads are soldered to the board on mine (R1).

I replaced mine temporarily with a jumper and that restored the calibration function.

[tibimakai]

Re: esr or cap tester

Mine died too. I barely used it a couple of times? I don't remember, that I have used it improperly.
I have replaced the batteries, but didn't change anything.
I should check that 1.0 Ohm resistor?
I have the 4.0 version and I have purchased it in April 2012.

[budm]

Re: esr or cap tester

16V into 1 Ohms is 16 A but at very short period of time. After 1TC, the voltage on the cap will be about 6V.

t = (C*V)/I.
http://www.coilgun.info/theorycapaci...orcharging.htm

[Kiriakos GR]

Re: esr or cap tester

I think that several mF at several volts carry quite a power

One 1000uF at 16V does not looks a nuclear reactor to me, but the boys who are planing to play with super capacitors, they must be 100 times more careful with them.

[Behemot]

Re: esr or cap tester

I think that several mF at several volts carry quite a power

[Kiriakos GR]

Re: esr or cap tester

you get huge currents flowing through the 0,25W (in later versions 0,5W) resistor.

I am not going to debate over this, even if I do not consider possible such event at the fraction of a second, to be capable to do such damage.

From the other hand if the true reason of such a damage in one ESR meter is due bad handling or irresponsible use, I am not surprised.

Before some time, some one got a fresh cheap multimeter and his first measurement was an electric fence.
The meter got toasted and he learned something useful too.

[budm]

Re: esr or cap tester

I have seen the resistor failed mode like that many time from many repair works. If you work on many many many many kind of electronics for so many many many many years, you will see lots of failure modes of the components.

[Behemot]

Re: esr or cap tester

It's possible. It is true that usually the resistor burns completely, but this may happen. It works there as a fuse - if you connect charged capacitor to it, the input transil shorts it but you get huge currents flowing through the 0,25W (in later versions 0,5W) resistor.

[Kiriakos GR]

Re: esr or cap tester

It should be 1ohm. Mine was over 30ohms.

Is that another funny story of yours?
Are you saying that a resistor on that PCB suddenly from 1 Ohm become 30 all by it self?

This is the most ridicules story ever.

[mmartell]

Re: esr or cap tester

For anyone who may find this info useful in the future remove and check R1. It should be 1ohm. Mine was over 30ohms. Replacing it temporarily with a jumper brought it back to life. Waiting on some 1ohm resistors to repair it properly.

Cheers!

[mmartell]

Re: esr or cap tester

I sent an email to support@radiodevices.ru

[mariushm]

Re: esr or cap tester

His username here on this forum is RusMike ... if you give him a PM, he's gonna receive an email with the PM.
Be patient, he doesn't check his emails often.

[mmartell]

Re: esr or cap tester

Thanks bro. I forgot the damn url was printed on the device.

[Behemot]

Re: esr or cap tester

Try support@radiodevices.ru or Skype mike_rd1.