555 Pinout

 

1) Ground. Connect this to ground. Remember to connect all grounds in a circuit together.

2) Trigger. A short low (less than 1/3 Vcc) pulse on the trigger starts the timer. By connecting this to ground we "turn on" the 555 timer.

3) Output. During a timing interval, the output stays at +VCC. Can source up to 200ma.

4) Reset. Forces pin 3 low if pulled to ground.

5) Control. Can be used to adjust threshold trigger voltage. Not used in our applications. Connect to ground with a .01uF cap to eliminate supply noise from Vcc.

6) Threshold. When threshold crosses above 2/3 Vcc timing interval ends.

7) Discharge. connects to ground when output goes low. Controls timing.

7) Vcc. Power supply. Typical range 4.5v to 16v.

 

 

 

 

 

 

 

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