Found in a 1970 EEE, this circuit generates signals that depend on the C1 capacitor. Transistors are general-purpose types.
Found in a Popular Electronics from the 90s, this circuit can act as a transmitter for an audio...
With the circuit shown in the figure, the frequency of a 5 MHz oscillator controlled by crystal can...
This circuit with two HT2030s powers 6 LEDs in a decorative flashing system. The circuit is from...