NPN

2N3904

Collector

Base

Emitter

The flat side faces up

You will need the following parts from your kit:1. Breadboard

2. 220 ohms resistor (red, red, brown, gold)

3. 3300 ohms resistor (orange, orange, red, gold)

4. NPN Transistor

5. 2 @ LED (light emitting diode)

6. 9 volt battery lead

7. 3 wires

8. 9 volt battery

9. Pushbutton switch

Use this schematic to construct the experiment.

220 Ohm

+

-9 volts

Quick Check:

Your circuit should like this one.

3.3K Ohmem

itter

colle

ctor

ba

se

1. Connect the 9 volt battery.

2. Observe the brightness of the LED’s.

3. Press the pushbutton switch.

4. Observe and compare the brightness of the LED’s.

5. Release the pushbutton, both LED’s should turn off.

Troubleshooting:

1. If the LED’s do not light up, check to make sure they in correctly.

2. Check the battery. Does it have voltage?

3. Are there any breaks in the circuit?

4. Is the NPN in the right way?