This sensitive circuit for triggering relays was found in an old English publication. It works with alternating signals applied to its input. Transistors are general purpose types.
We found this interesting configuration in a 1976 technical documentation. Equivalent diodes can...
Indicated by the Maxim Engineering Journal in the 90's edition, this circuit uses only one...
The gain of this circuit is given by the value of R1 that depends on the current in the...