Found in American documentation from the 90s, this circuit has the signal frequency determined by capacitors from C4, C3, C2 and C5 selected by digital switches.
P1 on this Radio Shack circuit is a 6 V lamp with current up to 500 mA depending on Q2. The...
This simple touch alarm, found in a 1995 documentation, uses common components and a triac to...
With the micro voltage regulator shown in the figure, we can design a power supply for small...