Relays up to 100 mA can be driven by the 555 with the recommended circuit. The circuit is from an article in the September 1992 Radio Electronics magazine.
This sensor works as an electronic push button, activating a power relay. The circuit must be...
This circuit is based on an old operational amplifier, having been found in documentation from the...
Found in a Maxim documentation, this 1980s circuit drives 4 LEDs on a bar scale. The circuit does...