ESR meter upgrades

[stj]

Re: ESR meter upgrades

here is your foto of using an LM4040 inplace of the TL431

[vinceroger69]

Re: ESR meter upgrades

stj ive noticed the last few months some more of these testers have come out i wouldnt mind a colour screen version 16 mhz which one are you recomending at the minute

[stj]

Re: ESR meter upgrades

there is only one colour unit as a kit / with software.

there are 2 others sold in cases that look interesting - wait a while.

[vinceroger69]

Re: ESR meter upgrades

there is only one colour unit as a kit / with software.

there are 2 others sold in cases that look interesting - wait a while.

Cheers will do im in no rush.

[Per Hansson]

Re: ESR meter upgrades

Do you know if an SCR should be possible to read on the transistor tester?
Specifically a S2514NH. (Attached datasheet).
It shows up just as a 15ohm resistor. (I am suspecting something is wrong with the SCR).

[stj]

Re: ESR meter upgrades

no idea, it may depend on gate current.

i cant tell you that low gate current triacs can be tested - because i tried one yesterday.

[momaka]

Re: ESR meter upgrades

Do you know if an SCR should be possible to read on the transistor tester?
Specifically a S2514NH. (Attached datasheet).
It shows up just as a 15ohm resistor. (I am suspecting something is wrong with the SCR).

That definitely sounds suspect. Check it with your multimeter. It's essentially like a BJT with an extra diode junction on the Collector.
See SCR Construction @ Wikipedia: https://en.wikipedia.org/wiki/Silico...r#Construction

That said, you should get an open-circuit between Anode and Cathode terminals (A and K), and a diode Vf between Gate (G) and Cathode (K).

Good point in asking if the TT can check this component. IIRC, I remember a picture of one showing it testing a TRIAC. Don't remember about SCR, though. I don't think I have any SCRs in my junk box so can't check.

[stj]

Re: ESR meter upgrades

the test current is very limited.

[Per Hansson]

Re: ESR meter upgrades

Thanks Momaka!

That said, you should get an open-circuit between Anode and Cathode terminals (A and K)

-I get 7MΩ

and a diode Vf between Gate (G) and Cathode (K).

-I get 0.036

Good point in asking if the TT can check this component. IIRC, I remember a picture of one showing it testing a TRIAC. Don't remember about SCR, though. I don't think I have any SCRs in my junk box so can't check.

I asked on eevblog too and got this reply:

This device is capable of recognizing Thyristors IF the gate current is <~ 5-6mA.
Your SCR requires minimum 20mA so cannot be recognized. Your SCR could well be OK.

Graham

I reckon it's dead, could this work as a replacement?
Thing sits in an electric fence controller...

https://www.elfa.se/en/thyristor-to-...00r/p/17201058

the test current is very limited.

I've seen one Chinese version with a booster circuit, I assume that would then have the possibility to measure my SCR?

[stj]

Re: ESR meter upgrades

the booster is voltage, not current - it's for zener diodes.

[momaka]

Re: ESR meter upgrades

-I get 0.036

That looks like a Gate to Cathode short-circuit.
Yup, I think it's bad. I had two big RCA 1884 SCRs from a very old HP DC power supply that were blown the same way. Also, yesterday I just pulled a TRIAC from a home food processor. Was O/C between A and K terminals with a short-circuit between the input A terminal and G . Thankfully, the IC and driving circuitry was undamaged.

I reckon it's dead, could this work as a replacement?

https://www.elfa.se/en/thyristor-to-...00r/p/17201058

Well, I am no expert on SCRs and TRIACs, but that looks about right. You got the same current and voltage ratings. The gate current on your replacement part is a little more sensitive, but I think that's a good thing, because then the controller should be able to drive it more easily (kind of like a MOSGET with a lower gate charge/capacitance).

the booster is voltage, not current - it's for zener diodes.

Yes, I think I remember readings something like that too.

Then again, all you need to test a Zener diode is a breadboard, a few resistors, and a power supply with a high enough voltage and current.

[stj]

Re: ESR meter upgrades

about swapping triacs.
one thing i learned the hard way - make sure you know if the original and replacement have an isolated tab or one linked to the center pin.

unless you want a live heatsink!!

[TheOnlyDocc]

Re: ESR meter upgrades

A few days ago my Tester DIY Kit arrived. But without any documentation. Only the PCB and the parts.
My question is if someone with the same tester can take a picture of it without the LCD installed? That would help a lot.

And i want to ask if it is possible to protect the tester against a charged capacitor. Or better protect the tester in case i forget to discharged a capacitor.
That are the parts i got from ebay (the 16Mhz crystal is still in transit but the LM4040 is already here)

[stj]

Re: ESR meter upgrades

i dont know why a foto would help? all the part values are marked.

[Dutch52]

Re: ESR meter upgrades

The assembly doc and manual are attached here.
Perhaps reading this thread will help you further:
http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/2400/

[stj]

Re: ESR meter upgrades

updates.
because i'm probably moving soon due to gentrification and all my shit will be in storage!

[momaka]

Re: ESR meter upgrades

updates.
because i'm probably moving soon due to gentrification and all my shit will be in storage!

Sorry to hear that stj . I absolutely hate moving myself. I hope you don't get dealt a bad card with that. Have you found a new place yet? (perhaps keep us updated in VIP.)

[stj]

Re: ESR meter upgrades

no idea about anything.

[Per Hansson]

Re: ESR meter upgrades

Thanks for the update, finally put in a 16Mhz crystal to test it, worked fine
Got any firmware built for 20Mhz too?

[stj]

Re: ESR meter upgrades

no, it cant do it because the delays are carefully tuned for each crystal speed.