The figure shows how to generate a sinusoidal signal using a CMOS integrated circuit. The circuit is from a Radio Electronics from November 1976. The frequency depends on the capacitors.
This circuit makes use of an operational amplifier from the 80's. The circuit can be implemented with...
When the power is cut off, this circuit keeps the flashlight on for a while, allowing it to be...
Using the CK722 this directional photometer was published in Radio Electronics magazine in July...