Current indicator (CB22132E)

In this circuit the voltage across the LED is limited by the diodes. The maximum current also depends on the resistor.

Digital Watch (CB18700E)
This digital clock has a traditional configuration with well-known CMOS integrated circuits. The...
Two Transistors MW Radio (CB12819E)
This experimental radio was obtained in an old Argentine publication. Germanium transistors are...
RRRRRTimed alarm for car (CB6776E)
This circuit was found in an EDN from the 90s. The circuit employs a double 555 and uses the...