We found this tube receiver in a 1950s Japanese publication. The circuit uses 5 tubes and has an RF amplifier stage for greater sensitivity. The power supply is not shown on the circuit.
This circuit can be used as a shield for the control of stepper motors from microcontrollers. The...
This circuit was found in a 1960s Motorola documentation. Transistors are types of the time and...
In the figure we have two possible configurations for multivibrators with relay. The idea comes...