This variable frequency circuit was found in a Popular Electronics from the 90s. The circuit outputs to a small speaker and can be powered by voltages as low as 3 V.
This circuit was found in a 90s Radio Electronics. The integrated circuit admits an equivalent. The...
Suggested by Radio Electronics from the 90s, this circuit is suitable for NiCAd batteries with a...
To control direct current loads, under voltages between 12 and 200 V, and currents up to 3 A, we...