ESR Meter Help

[duldog]

Good day folks!

i built the two esr meters presented in these two links:

http://www.qsl.net/iz7ath/web/02_brew/15_lab/06_esr/fig03.gif
http://members.shaw.ca/swstuff/esrschematic.png

they work as expected but i have several questions on how i can modify them to suit my needs.

for the first link:
how can i modify the meter circuit so that it deflects half-scale at about 10ohms esr? (the circuit deflects about 80% of the scale with 10 ohms at its probes).

for the the second link:
how can i modify the circuit so that it can drive a 250uA meter?(it works ok on 50uA).

thanks a million!

 

[hjames]

If you want to make a ammeter less sensitive, put a resistor in parallel with it.

As for the second one, reduce the value of R17.

 

[duldog]

If you want to make a ammeter less sensitive, put a resistor in parallel with it.

As for the second one, reduce the value of R17.

thanks for the reply boss!

ok, i reduced r17 down to a few hundred ohms and even shorting it out completely, i only got about 50% deflection even after adjusting the series pot. any other ideas? thanks!