Current indicator (CB22132E)

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

Varicap Variable Frequency Oscillator (CB13124E)
The great advantage of the circuit shown in the figure is the fact that its frequency is...
12 V x 1 A Power Supply (CB1172E)
This power supply provides a12 V stabilized output. The transistor must be provided with a good...
Control for miniature railways (CB7079E)
Found in an American publication from 1968, this circuit can be made based on a TIP42 that must be...