This circuit was found in Ferranti's 1974 transistor manual. The transistors are from the period and the frequencies generated are between 50 Hz and 2 kHz.
This circuit turns a lamp on and off with alternate touches of a switch. Modern Darlingtons can be used....
This circuit with the CK722 was found in a Raytheon publication from the 60's. The relay is of the...
This circuit was found in Radio Electronics magazine from July 1960. The components used are...