Simple 5V regulator (CB8815E)

This simple 5.6 V regulator circuit was found in a 1966’s Philips. The zener can be changed to obtain other voltages.

Supercapacitor charger LTC3225 (CB15570E)
More and more supercapacitors are being used as supplementary sources of energy in several...
RF Switch with Varactor Diodes (CB24707E)
Varactor diodes are our varicaps of today. This circuit for switching signals in an RF circuit was found...
Current Limit (CIR035)
In this circuit the output current is limited by R3. For a 300 mA current, R3 must have 12 Ω. For...