Diode Problem
Problem Diode4P07

Name__________________________________

• Here is a diode rectifier circuit.
• The input is a sinusoidal signal at 60 Hz.
• You want the output voltage to droop no more than 5%.
• Estimate the time constant of the RC parallel combination that will produce a droop of no more than 5%.
• To analyze the circuit and produce an estimate, assume that the capacitor charges to the peak of the sine wave, and that it discharges for an entire cycle.
• Does that give an upper limit or a lower limit on the time constant?  In other words, should the time constant be larger or smaller than the value you found?
• If the capacitor is 4.7 mf, what is the value of the resistance?

• You may want a link to the simulators for this kind of circuit.
• This link takes you to the simulator that uses an ideal diode model.
• This link takes you to the simulator that uses adiode model that has a 0.7v threshold.
• When using the simulators, you probably want to use 0.6 Hz - thus scaling the frequency down by a factor of 100.  That means that the time constant you input will be 100 times too large.  For example, if you find a 5 second time constant works in the simulator at 0.6 Hz, you would need a .05 second time constant at 60 Hz.