TTEC 4284 exp 7

Transistor as a switch:

Components: 1 x Small Signal NPN transistor, 2 resistors

Exercise: Connect the circuit as shown in Fig 12 and switch on the power supply.

Connect the multimeter between base and the emitter. Note the voltage reading and explain what this reading is indicating:
The reading that was shown on the multimeter was 0.71v , what this reading is indicating is that the voltage given to us by the multimeter is the voltage needed to let the current flow across the base and emitter ports.

Connect the multimeter between collector and emitter. Note the voltage reading and explain what this reading is indicating:
The reading that we got from the multimeter was 4.87v. This indicates that the transistor is still in Active Region but near cut off point, so therefore there is a slight amount of amperage flow in the circuit but not alot due to it being so close to it's cut off point.

In the plot given, what are the regions indicated by the arrows A & B?

Plot A: Saturation Area

Plot B: This is the cut off point














How doe's a transistor work in these regions? Explain:
The term "Saturation" means that the transistor is at full working capacity and is giving the most amount of amperage to the circuit as it possibly can, this also means that the V at the base is higher than the collector and emitter.

When the term "Cut off point" is used, this means the circuit will not be getting its full potential of amperage, this also means the collector is higher than the base and emitter, which means that the circuit will not be recieving amperage.

What is the power dissipated by the transistor at Vce of 3 volts?
Pd = IxV
Ic = 13
V = 3
Pd = 0.013x3 = 0.039 power of 3.
Pd = 3.9v

What is the Beta of this transistor at Vce 2,3 & 4 volts?
Beta = Ic/Ib
2v = 19/0.7 = B(27.142)
3v = 13/0.5 = B(26)
4v = 5/0.2 = B(25)