EXPERIMENTNo.4

EXPERIMENT No. 4

Components: 1 x resistors, 1 x 5V1 400mW Zener diode, 1X Diode1N4007 .

Exercise: Obtain a breadboard, suitable components from your tutor and build the following circuit.

                Vs=10 & 15v, R=1K ohms

                                                                                    Fig 7

                                    10 Volts                                                           15 Volts

Volt drop V₁:   4.62v                                                               4.77v

Volt drop V₂:   0.67v                                                               0.67v

Volt drop V₃:   5.29v                                                               5.44v

Volt drop V₄:   5.24v                                                               9.68v

Calculated current A:                                                           I = V/R = 15/1000 = 0.015A

I = V/R = 10/1000 = 0.01A

Describe what is happening and why you are getting these readings:

v1, v2 and v3 show similar readings between 10 and 15 volts. V1 is the zener voltage needed to move electrons through the diode to turn it on. V2 shows the voltage required to move electrons through the diode boundary layer to allow electric charge to flow. V3 is the zener voltage plus the voltage to turn the diode on. V4 is the voltage being consumed by the resistor. The voltage drop across the 1kohm resistor for the Vs of 15v is the only difference. This is because there is more Vs so the resistor has to consume more volts to add up the total voltage supply because this is a series circuit. The current value stays the same through out the circuit at 0.01A at 10v and 0.015A at 15v.