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.
This circuit is from 80's documentation. Operational equivalents can be used. The power source is 5 V...
This circuit allows feeding a small semiconductor laser to obtain a useful resource for...
This low-current control circuit has a lamp as a load, but can have other types of devices, such...