Re: Cheaper ESR meter
Hi Mubashir
Just to confirm, is this the one your working on?
http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm
According to post No.4:
'At the output of the opamp we separate the AC and the DC components. First we see a low pass filter, composed by a resistor and capacitor, which allows the DC component to drive the base of the transistor which controls an LED. This LED will light if the capacitor under test is shorted or has high leakage current.'
My understanding would be that if you were to connect the 2 test probes together then this would act as a shorted cap and light up the LED.
Does your LED light up when the 2 probes are connected? This should work regardless of meter output.
This would at least show that something on your prototype is working.
Another point would be to check which resistors (R20, R21) you are using, the schematic shows 1k trim and 680ohm for a 500uA meter, what rated meter are you using? Have you made adjustment to R21 with any results obviously with probes shorted or with resistor across probes?
Rob
Hi Mubashir
Just to confirm, is this the one your working on?
http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm
According to post No.4:
'At the output of the opamp we separate the AC and the DC components. First we see a low pass filter, composed by a resistor and capacitor, which allows the DC component to drive the base of the transistor which controls an LED. This LED will light if the capacitor under test is shorted or has high leakage current.'
My understanding would be that if you were to connect the 2 test probes together then this would act as a shorted cap and light up the LED.
Does your LED light up when the 2 probes are connected? This should work regardless of meter output.
This would at least show that something on your prototype is working.
Another point would be to check which resistors (R20, R21) you are using, the schematic shows 1k trim and 680ohm for a 500uA meter, what rated meter are you using? Have you made adjustment to R21 with any results obviously with probes shorted or with resistor across probes?
Rob
Comment