Current indicator (CB22132E)

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

Fluorescent SCR Inverter (CB12328E)
This circuit is from a 1967 publication. It is possible to power a fluorescent lamp from a 12 V...
Modified Hartley Oscillator (CB21138E)
This circuit was found in old American documentation. Transistor is general purpose and coil rated...
Schmitt Trigger LM3900 (CB5049E)
With a strong positive feedback (via a 10 M resistor) we can get the trigger setting for the...