You should not exceed the power rating of q1 and it

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: input is the reference voltage. ⑤ ② ⑦ D1 VC D2 ③ RL CL ⑧ Figure 4(a). Unregulated power supply. VC VOUT Q1 RZ VREF 3 + OP-AMP1 7 6 DZ - 2 4 RLOAD R1 R2 Figure 4(b). Linear voltage regulator. (See Figure 10.32 of Hambley) The reference voltage VREF is provided by the zener diode to the non- inverting input of the op- amp feedback amplifier. Since there is no current into the op- amp input you simply want to pick a value for RZ which will limit the current through the diode so that the power dissipated by the zener diode remains within the diode’s power rating. The feedback voltage VFEEDBACK is provided to the inverting input of the op amp feedback amplifier by the R1- R2 voltage divider. For a typical design output of 12 volts using a 5.1 volt reference zener diode you would select R1 and R2 to provide a voltage division from...
View Full Document

Ask a homework question - tutors are online