Found in a 1965 General Electric Hobby Manual, this timer was originally created to operate with photo magnifiers of the time. The circuit can be adapted for other purposes.
This circuit was found in an Electronics World of 1969. Transistors are general-purpose types. It...
It is like to the previous circuit with a lock that keeps the LED on at the end of the timer. The...
This good quality audio amplifier with an output of about 10 W with the original transistor was...