Transistor as a Switch and Amplifier

Below picture shows the real life circuit connection to use a transistor as a Switch and Amplifier, not a schematic.

For this example, we are using TIP32C PNP Transistor. While developing this circuit, I had the below idea in mind to make things easy :\

• For NPN Transistors, the base needs to be positively induced

• For PNP Transistors, the base needs to be negatively induced

So, in this case, since we are using PNP Transistor type, then the base needs to be negatively induced.

Another important aspects that we need to look when using a transistor is the maximum current and voltage ratings. This information can be found in Datasheet of your transistor. Be sure to not exceed any of maximum values.

To start developing, let find out the amount of current that we need for this circuit. To fire up the DC motor, we would need around 0.2A with a minimum of 5V. In other word Ic = 0.2A.

Ic=Ib.B

0.2=Ib.(10),considering 10 as the lowest of gain for TIP32C

Ib=0.2/10=0

Also, we know that Ib cannot be more than 1A from our datasheet which is fitting to our requirement.

Now, let's decide our circuit at base of the transistor.

Also, we know that Ib cannot be more than 1A from our datasheet which is fitting to our requirement.

Now, let's decide our circuit at base of the transistor.

My Power Supply is 8V. Hence, I need to decide R1 and R2 value that can produce Ib current of 0.02A.

V=IR

8V=(0.02)R

R=8V/0.02=400 ohm

Hence, my combination of R1 and R2 should give a value around 400 ohm.

The result of Ib and Ic current is shown in my video where I measured using the voltmeter to prove the results.

Good Luck Trying! If you have any comments or question, feel free to drop it. I will try my best to attend to your comments :)