This circuit has its frequency controlled by a 1MHz crystal. The circuit must be powered by a voltage of 5V. The capacitors must be ceramic. The generated signal is rectangular.
The HA2620 integrated circuit used in this comparator is from the 80's, but the setting can be...
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...
This improvement of the MA1026 digital clock and thermometer, improved over the previous two...