This circuit of a Popular Electronics from the 90s makes use of components of the time. The circuit has sampling and retention capabilities and a conversion rate of 1V / kHz.
This circuit makes use of a special LM195 power transistor not very easy to obtain. The circuit is from...
Found in documentation from the 90s, this circuit can employ other comparators in the series such as...
Suggested by Philips in a 1970 publication, this circuit uses components from that time. No...