<^< Reservoir and Smoothing Circuit | Course Index | Simple Power Supply >^>
| Objective:
| To investigate the operation of reservoir and smoothing circuits.
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| Underpinning knowledge:
| Bridge rectifiers. Peak and r.m.s. values of an alternating voltage. Capacitance. C-R low-pass filters.
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| Apparatus:
| TINA circuit file, or apparatus to make the following circuit.
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| TINA Circuit File:
| Click here to download circuit file
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| Initial Settings:
| Alternating current supply of 10V at 50Hz.
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| Requires:
| Paper, Linear graph paper, pen or pencil.
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| Instructions:
(a) Use the oscilloscope to display two or three cycles of the voltage waveforms developed across the reservoir capacitor (C1) and smoothing capacitor (C2) using a common time scale.
(b) Sketch the waveforms in (a) and include labelled axes of voltage and time.
(c) Measure, as accurately as possible, the peak value of the ripple voltages across C1 and C2.
(d) Repeat steps (a) to (c) with C1 = C2 = 100mF and C1 = C2 = 1000mF
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Observations:
Comment on the shape of the waveforms and the relative values of the ripple voltages produced across C1 and C2. Comment on the effects of decreasing and increasing the values of C1 and C2 on the amount of ripple present on the output voltage
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| Further work:
The effect of ripple on a power supply is worse when the supply is heavily loaded (i.e. when a relatively low value of load resistance is connected to it and appreciable current is drawn from it). Investigate the effects on the output voltage and ripple voltage produced by the power supply (with C1 = C2 = 470mF) when connected to load resistance's of 200Ω, 100Ω, and 50Ω.
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<^< Reservoir and Smoothing Circuit | Course index | Simple Power Supply >^>
