Cheap ESR Meter

[gregmcc]

Has anyone ever built one of these - I had a ESR meter which has recently died and need to check a few caps for a monitor so thought I'd give this one a go.

https://www.qsl.net/iz7ath/web/02_brew/15_lab/06_esr/index.htm

I've build the ESR meter but can't seem to get it to work. If anyone has built one I'd appreciate a few pointers. I've attached a few scope screenshots.

On the circuit IC1A is generating a square wave. The collector is TR1 is shown here (**broken link removed**)

and the collector of TR2 is here (**broken link removed**)

If I short the cap out the LED should come on but it doesn't. The pins 5 and 6 of IC1 are both 0V

Any tips of where I could be going wrong. Such a simple circuit its driving me crazy!

 

[nayr_1218]

anlog esr meter

hi
has anyone ever built this kind of esr meter? http://members.shaw.ca/swstuff/esrmeter.html
because i need help regarding potentiometer connection to panel meter and i cant set to zero when i shorted test pt.
..i used 20k potentiomer and only in 25ohms to set,not zero set.
thnks in advance and hoping more coment to get and aswer this problem.

 

[Jaguarjoe]

Has anyone ever built one of these - I had a ESR meter which has recently died and need to check a few caps for a monitor so thought I'd give this one a go.

https://www.qsl.net/iz7ath/web/02_brew/15_lab/06_esr/index.htm

I've build the ESR meter but can't seem to get it to work. If anyone has built one I'd appreciate a few pointers. I've attached a few scope screenshots.

On the circuit IC1A is generating a square wave.

IC1A does not make a square wave. It is used to provide a power supply 'common' at half the battery voltage. It's a "rail splitter"

 

[KeepItSimpleStupid]

1st Check IC1-A for the +- (1/2 the battery voltage). i.e. +-4.5 V on the schematic.