Lab 6: Transistor Switching

In this lab we worked with transistors and built circuits using them.  Transistors are like a switch but instead of just a simple on/off, they can switch the flow of electricity.  In this first circuit we built, the transistor is "turned on" by a push button which allows the flow of electricity to the base.  This flow of electricity to the base is what switches the transistor to allow current to flow through it.

Here, I'm pushing the button which is turning on the transistor, which then allows the current to pass through and turn on the LED.



In this next part, we removed the push button switch and resistor #2 and replaced it with our fingers.  Since our bodies have high resistance, they act similar to the small resistor components.

Here, I'm bridging the connection between the wires with my fingers and current is flowing through my body.


Next we set up a circuit with a 100k potentiometer and resistors and used our 5V power supply.  An Ammeter was used to measure the current passing through different points in the circuit, before or after resistors and the transistor.

Here, the ammeter is registering the change in current as I am adjusting the potentiometer.  The Beta (Gain) of our transistor was determined to be 220.  The current was also determined to saturate at 13mA.


Lab 6 finished!