This circuit was obtained in an American documentation from the 80's. The transistors can be equivalent to those indicated and the crystal can reach a few tens of megahertz.
This circuit can be used in alarms, data links or áudio links using IR radiation. The circuit is...
This amplifier can amplify signals from 10 Hz to 17 MHz with more than 30 dB of gain. The circuit is...
This circuit, found in a publication from the 1970s, produces a 1 Hz sinusoidal signal....