Found in a Popular Electronics from the 90s, this circuit uses common components with several operational options, including the use of an optocoupler that allows its application in a shield.
The circuit shown is from Texas Instruments optoelectronics documentation. The input signal is...
It is an improved version of the previous circuit with a voltage follower that reduces the load...
This circuit was obtained in an American documentation of 1975. The transistor can be the BC548, and...