This 50% active cycle TTL clock generates signals from 4 to 20 Hz. Its power must be supplied with 5 V and other frequencies can be generated with capacitor replacement.
This ouput push-pull stage using bipolar transistors was found in a publication of the year 1968....
LEDs are diodes and can be tested with a simple configuration that allows the display of its...
This circuit can drive a loudspeaker with near 1 W of Power from 6 to 9 V supplies. The circuit...