This circuit was found in the December 1992 Radio Electronis magazine. R2 is an NTC, there is a MOV protector or NTC thermistor. The current depends on the thermistor used.
This key is turned off by a touch sensor. The time it remains active depends on capacitor Cx. The...
This circuit was developed to test suspect 4001 and 4011 integrated circuits. The circuit is from...
This circuit was obtained in a 1979 publication. The operational amplifier is of the type with...