Found in American documentation, this circuit for modulated infrared signals can be tuned to a certain frequency. The photodiode can be of any type.
Wien Bridge This Vienna bridge oscillator generates a sinusoidal signal whose frequency depends...
This audio oscillator can also be frequency controlled by an LDR. The circuit is from a 1975...
In the 1992 publication, this amplifier is announced as having 400 W pmpo. Power transistors should...