This circuit is from 1980s documentation. The maximum operating frequency is 3.5 MHz. The current of the LED can be from 0 to 100 mA. The integrated circuits used are from that time.
This circuit was found in Electronics Now. With it the dialing signals of a telephone are...
This traditional configuration of a white noise generator that uses the junction of a transistor with a...
This circuit generates an accurate 1 Hz signal controlled by a crystal. The circuit is from 1995...