This circuit is from a 1924 book by Gernsback. The receiver uses two tubes and listens to headphones. Power is supplied by battery with the indicated voltages.
This flasher was found in an old Hands On, but uses common components. The optocoupler can be...
The LM12 is a high-power operational amplifier capable of providing a 4 A output current with a 40...
The circuit presented was found in the Linear Applications Handbook of the National Semiconductoir of 1994....