PNP Foundations of Technology PNP © 2013 International Technology and Engineering Educators Association, STEM Center for Teaching and Learning™ Foundations.
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Foundations of Technology
PNP 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning Foundations of Technology Teacher Resource Unit 4 Lesson 4
2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning Foundations of Technology
Objective:You will build a simple circuit to show that a Positive-Negative-Positive (PNP) transistor will serve as a current amplifier.PNP2N3906CollectorBaseEmitterThe flat side faces up
You will need the following parts from your kit:Breadboard220 ohms resistor (red, red, brown, gold)1000 ohms resistor (brown, black, red, gold)PNP Transistor2 @ LED (light emitting diode)9 volt battery lead3 wires9 volt batteryPushbutton switch
Use this schematic to construct the experiment. 220 Ohm+-9 voltsQuick Check: Your circuit should like this one.1K Ohmemittercollectorbase
This circuit will light the LEDs. Electrons will not flow through the base collector until there is current through the base emitter combination.This makes a small current control a large current which is referred to as amplification.An increase of current through the base emitter will result in a larger current through the base collector side of the circuit.If you change the 1K Ohm resistor you will see a change in LED brightness. You can also measure this with your Amp meter.
Connect the 9 volt battery.Observe the brightness of the LEDs.Press the pushbutton switch.Observe and compare the brightness of the LEDs.Release the pushbutton, both LEDs should turn off.Troubleshooting:If the LEDs do not light up, check to make sure they are in correctly.Check the battery. Does it have voltage?Are there any breaks in the circuit?Is the PNP in the right way?
By completing this experiment, you should have noticed the light of the LED on the collector emitter was brighter than the LED from the base emitter. The LEDs only light up after you press the button.In complete sentences, write what you learned about PNP transistor in a circuit.
International Technology Education AssocSlide #*TITLE SLIDE12/01/2009STEMCenter for Teaching & Learning Engineering byDesign