Electromechanical Counter (CB21682E)

This photoelectric circuit from a 1960 publication uses a 6.3 V electromechanical counter, common at the time.

Fast peak detector (CB20893E)
This circuit was found in a National Semiconductor manual from the 1980s. The integrated circuits used...
Unijunction transistor sequential timer (CB21400E)
This circuit was found in Motorola documentation from 1968. Transistors can be modern equivalents, just...
Relay Control (CB21358E)
This circuit was obtained from an English documentation, with the purpose of carrying out the...