Revision as of 16:55, 13 February 2011

Lab 8 The Diode Objective: Measure the current-voltage curve of a silicon diode.

Reverse current

Construct the circuit below using a DC power supply, a diode.
attach an Oscilloscope set to 1M[math]\Omega[/math] input impedence as shown in the circuit diagram. The oscilloscope will serve as a Resistor to measure the voltage across the diode and calculate the current.
Measure the diode reverse current [math]I_r[/math] as a function of the DC supply voltage.

now swap the diode direction and repeat the measurement in the previous section.

make the same measurements in parts 1 and 2 above for a germanium diode.
Plot the diode current (on the ordinate) versus the diode voltage (on the abscissa)for both diodes on the same graph. (50 pnts)

The reverse biased diode acts like a constant ____________. (10 pnts)
The forward biased diode has a very __________ resistance. A reverse biased diode has a very ____________ resistance.(10 pnts)
The approximate DC forward resistance for diode #___________ is _________ when the forward current is _______________.(10 pnts)
The approximate DC reverse resistance for diode #___________ is _________ when the forward current is _______________.(10 pnts)
The silicon diode #___________ has an approximate turn on voltage of ___________.(10 pnts)

@@ Line 7: / Line 7: @@
 # attach an Oscilloscope set to 1M<math>\Omega</math> input impedence as shown in the circuit diagram.  The oscilloscope will serve as a Resistor to measure the voltage across the diode and calculate the current.
 #Measure the diode reverse current <math>I_r</math> as a function of the DC supply voltage.
+[[File:Lab8_ReverseCurrentDiode.png|200 px]]
 =Forward Current=