This circuit turns off a load after an interval of 8 to 80 seconds adjusted on the potentiometer. The circuit is from a Radio Electronics June 1970. The time depends on C1 and can be changed.
The gain of this alternating voltage amplifier is 100 times, depending on the 1M-ohm resistor, which...
This simple field strength meter is from a transistor book from the 60's. The transistor is made...
We found this circuit in an 80's Electronic Design. It makes use of couplers of the time that can...