555 Timer

The 555 Timer chip is designed to function as a monostable (one stable state) multivibrator or as an astable (free running) multivibrator.

It contains the equivalent of approximately 20 transistors,resistors, diodes etc. It is used for timing or switching circuits which give pulsed or digital outputs.

Data: Pin

1. connected to the negative (-ve) supply
2. TRIGGER a voltage greater than 1/3 supply volts enables the chip.
3. OUTPUT is equal to the supply volts when the output is on (600mW max).
4. RESET when connected to positive supply volts.
5. CONTROL OUTPUT applying a variable voltage to this pin varies the frequency of the output.
6. THRESHOLD a voltage higher than the threshold voltage (2/3 supply volts) turns on the output.
7. DISCHARGE when the output is turned on the pin goes to 0v allowing discharge of any connected capacitor.
8. positive supply voltage (+ve) (4.5v - 16v)

Uses: Oscillators, triggers, inverters, timers.