This three-transistor circuit was found in Radio Electronics magazine from May 1969. The circuit is for hearing aids and has earphone listening.
This circuit should be used with low frequency signals only. The circuit is from a documentation from the...
This alarm circuit was found in the April 1975 issue of Radio Electronics magazine. It is a basic...
This circuit supplies 5 V from two AA batteries. The output current is 4 mA, resulting in an 11 mA...