A
Ancient_Hacker
- Jan 1, 1970
- 0
[email protected] wrote:
Okay, if you only need 20KHz bandwidth, I'd definitely roll off the
gain with some small capacitors. Try 220pf across each 470k resistor
for starters.
Ans since it's coming from a coil, there's no DC that you could ever
want, so please put a Dc blocking capacitor between the stages. That
will get rid of 83 times of your offset problem.
You definitely need to put the amplifier in a metal box, so you should
run your coil thru a short cable to the amplifier box. the IC's should
be separated by at leasty an inch or so from each other, each one
decoupled from the plus and minus supplies with 100 ohm resistors and
100 uF capacitors.
Okay, if you only need 20KHz bandwidth, I'd definitely roll off the
gain with some small capacitors. Try 220pf across each 470k resistor
for starters.
Ans since it's coming from a coil, there's no DC that you could ever
want, so please put a Dc blocking capacitor between the stages. That
will get rid of 83 times of your offset problem.
A ground place near the metal detector coil is a no-no.
You definitely need to put the amplifier in a metal box, so you should
run your coil thru a short cable to the amplifier box. the IC's should
be separated by at leasty an inch or so from each other, each one
decoupled from the plus and minus supplies with 100 ohm resistors and
100 uF capacitors.