Preamplifier stage (CB8934E)

This circuit is from a 90s Popular Electronics. It appears elsewhere on this site. Q1 can be any general purpose transistor.

Temperature Control (CB6003E)
This circuit functions as a thermostat triggering a relay when the boil control temperature...
Crystal Oscillator (CB25445E)
This 1 MHz oscillator was found in the February 1992 issue of Radio Electronics magazine. The...
CMOS Voltage Multiplier (CB4635E)
In this circuit we have the voltage multiplied by 5, obtaining between 50 and 80 V output when the...