This circuit is suggested by National Semiconductor in its Linear Applications Handbook. The LM3909 integrated circuit consists of a very low consumption oscillator with a power supply of 1.2 V.
With this circuit, from an old operational datasheet, it is possible to measure the CMRR,...
Found in a Popular Electronics from the 90s, this circuit can be adapted to use LEDs. The power...
The circuits shown in the figure, that of an infrared video signal transmitter and receiver, were...