This switched power supply was found in a 70s documentation. The basic components are from that time. The circuit operates at 200 kHz and has a ripple below 200 mV.
This circuit was found in a Popular Electronics from the 90's. The circuit has gained 10 to 20 dB...
This simple circuit uses a car ignition coil. The circuit appeared in the 1983 Radio Electronics Annual...
The modified Hartley oscillator seen in the figure can generate signals ranging from 3 MHz to 10...