Designing a rectifier/ filter/ regulator

dear

my advice for you: visit the location in intrnet (tips-eng forums ) and then select

(circuit engineering fotums)

This is a first year college question.

Anyways, lets start with your AC, full wave rectify.

Now that will have lots of ripple, so you want to filter that with a cap.

Now we will use some loose rules of thumb, since you will be selecting nearest available parts anyways.

Decide how much ripple is acceptable. With a 60 HZ source there is 1/120 sec from peak to peak of the rectified sine wave. You are drawing 100mA. I = C* dV/dt or C=I*dt/dv where I = 100mA, dt = 1/120, dv = ripple volts pk to pk.

So we use 1000uF to 10,000uf anyways.

Now we have less than 1 volt ripple, we need some head room for the regulator to work with, say 2 volts or more, so now we have 7+ volts pk, so 5 volt AC or 6 volt ac 1 va transformer works.

Key part is now a 3 terminal integrated 5 volt regulator like a Fairchild uA7805. Look up the spec sheet, add the output capacitors as required by data sheet and you are off to the races. (those .33uF caps are required for high frequency stability, so don't leave then out.)

By the way a little research of the Fairchild data sheets would give you all the details you need.

Hi: Begin by reversing D2 and D3. DickL

useful comments

Thanks

Please correct the "Bridge-Rectifier's connections"
1. Reverse connect D2 & D3. As posted in post #3

In present connections it is not a Bridge-rectifier but Ring-Modulator or demodulator form, though it requires 2 different Signals to be mixed [modulated] or demodulators.

2. Use of D6 ???

3. Zener Diode Regulators are called Shunt-Regulators # & are poor in regulations &
Lossy regulators because they draw always full-load current.

Think of Fixed-voltage Regs.

# [Load is connected in Parallel with Regulator ]

In such Ccts current is shared by zener & Load.
In off-load all the current flows through zener and as the load increases current through zener is decreased. Roughly total-current remains constant.

In your case you should work for 200mA, so a zener more than 1.5W rating be planned.
1N-4734 is 5.6V while 1N-4733 is 5.1 V & is close to 5.0V as required.
Any-how confirm its wattage ratings. My DATA has no indication of wattage.

Also keep in mind the value & wattage of R1.

Zeners produce Noise so a ceramic 0.002 to 0.0047 ų F cap be used in parallel to it.

Larger filter caps are required to as posted in #2.

4. Are you indicating a resistor connected in out-put as the load or an additional resistor.
Its need ???