READING Text, Section 20-4 OBJECTIVES After performing this experiment, you will be able to: 1. Explain how an active diode circuit differs from a passive diode circuit. 2. Test two active diode clipping circuits, comparing the output and input signals. 3. Test an active diode dc restoring circuit. MATERIALS NEEDED Resistors: Three 10 k, one 1.0 M Capacitors: One 0.1 F, two 1 F One 10 k potentiometer Two signal diodes 1N914 (or equivalent) 741C op-amp SUMMARY OF THEORY An active diode circuit is one that includes an op-amp to "idealize" the normal diode response. Instead of a 0.7 V offset and the forward resistance of a diode, the active diode has nearly zero offset and an idealized response. Active diode circuits have broad application in signal processing, where a circuit changes an input signal in some way. Included in this category are rectification, clipping, clamping, and various conversions. The "active" part of the diode circuit is an op-amp. For low frequencies (<1 Notice