Ultrasonic repellent (CB9384E)

Found in Radio Electronics from the 90s, this circuit is based on the 555 directly feeding a small tweeter. An amplifier stage can be added.

| Clique na imagem para ampliar |

Non-Inverting Amplifier (CB14887E)
The gain of this amplifier depends on the component values as well as the operating range and the...
Proximity Voltage Indicator (CB4645E)
This circuit indicates whether a cable or wire is energized by simply approaching its antenna. The...
Transistor Curve Tracer (CB23986E)
This transistor curve tracer was described in a December 1969 Radio Electronics article. It...