This common transistor-based circuit provides power for 20 mA common white LEDs from a single 1.5 V battery.
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....
For signals up to about 500 kHz modulated in amplitude and transmitted by the power network, the...
This circuit was found in the March 1984 issue of Radio Electronics magazine. The sensor is a...