This common transistor-based circuit provides power for 20 mA common white LEDs from a single 1.5 V battery.
This old circuit uses na operational amplifier not easy to find in these days. But the circuit can be...
This circuit was found in the December 1991 issue of Radio Electronics magazine. The circuit is...
The used diode is an unusual component today. We found this 12 V regulator in documentation from the...