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sr0019

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## Homework Statement

I have an unregulated power supply circuit consisting of the following:

Transformer, 10:1 ratio, 230VAC rms 50Hz incoming voltage

Full Wave Bridge Rectifier

Filter Capacitor, 1000μF

Load - Resistor, 25Ω

Find the following:

1) RMS & peak voltage across secondary winding of the transformer

2) Peak voltage across the capacitor

3) Peak to peak and rms ripple voltages

4) Load d.c. voltage & current

I am not after answers - just guidance & a push in the right direction. I want to learn, rather than just be told. The real problem I tend to have is confidence that I am doing the right thing. This applies to my answers for 2,3 & 4. Apologies if I have missed any information/not set out the query correctly!

## Homework Equations

For 1) V2/V1 = N2/N1

For 2) VL pk = Transformer secondary V (V2) - 1.4V (V.D. due to rectifier)

For 3) Vr = IL/fC (remembering that the frequency will be double that of the incomer, as it is bridge rectifier)

For 4) To be determined

## The Attempt at a Solution

1) V2/V1 = N2/N1. V2/230 = 1/10 . Therefore, V2 = 23V rms or 32.5V pk

2) VL pk = V2 - 1.4V. 32.5 - 1.4 . Therefore, VL pk = 31.1V pk

3) Assuming Vdc = VL pk , approx value of IL = VL/RL. Therefore, IL = 1.24A

Vr = IL/fC . Vr = 1.24/(100 x (1000 x 10^-6)) . Therefore Vr = 12.4V pk

4) I am yet to attempt number 4 or convert 12.4V to RMS, as I feel my answer for 3 is completely out - the ripple voltage seems too big.

Many thanks in advance