This timer, like the previous circuits, uses a currently uncommon integrated circuit. The time is given by capacitor C1 and R2 which has the range of values indicated in the diagram.
This circuit is an improved version of the previous ones with the LM3914. We found it in the March...
This transmitter for short range in the medium wave range was found in a Raytheon publication from...
In this circuit the transistor switches when the voltage reaches the pre-set value in the trimpot. The...