Ultrasonic repellent 4011 (CB9385E)

This circuit was found in Radio Electronics from the 90s. The transducer is a tweeter and the power transistor must have a heatsink.

| Clique na imagem para ampliar |

Telegraph Practice Oscillator (CB6474E)
Found in a 1965 Radio Shack documentation this oscillator can be used with modern general purpose...
Dual Tuning Circuit with Varicap (CB13344E)
In the figure we have the way to use a single control voltage to act on two varicaps...
Sensitive touch switch (CB9561E)
Found in a 90s documentation, this switch that is also sensitive enough to operate capacitively uses...