Using the 555 and 4020, this timer was found in the July 1994 Radio Electronics magazine. The relay is voltage-dependent, and the transistor is general purpose.
In the figure we have a very simple trigger circuit for an SCR that powers a 12 V lamp whose...
With the use of precision resistors and capacitors, this circuit with programmable unijunction transistor...
This 15 W power stage was found in Radio Electronics magazine from August 1959. The transistors are the...