Experiment 3 - The Output (OUT)

How do you connect the NE555? Find out how to connect OUTPUT.

The OUT-output of the NE555 is on pin 3. It can only take up two states...

• OUT = LOW-Level (here 0 V)
• OUT = HIGH-Level (here 9 V).

Internal circuit diagram OUT-output of the NE555.

In the circuit you use two LEDs (LED1 and LED2), to indicate the state of the output...

• OUT = LOW:      LED1 is on.
• OUT = HIGH:     LED2 is on.

When you connect the battery and start to use circuit, the NE555 is always in the state OUT = LOW (LED1 is on).

Circuit diagram OUT output of the NE555.

Circuit OUT output of the NE555. (Enlarge)

Internally the output uses a separate output stage. This allows the output (OUT) to be loaded with up to 200 mA.

In the next step you change the state of the output.