This circuit takes advantage of the noise generated at the reverse biased junction of a germanium diode. Other types of diodes can be used. The signal is weak.
This circuit for currents from 500 mA to 1.5 A was found on a Ham Radio from the 90s. R4...
Found in a PE Hobbyst in 1991, this 13.6 V power supply with a 2 A current is suitable for supply...
This circuit generates low-frequency sinusoidal signals. The variable capacitor is dual and the...