I really need your help - Bridge rectifier

bridge rectifier rc

I built a bridge rectifier with a filter but I need to find my ripple voltage

1 how can I compute it?
2 how can I measure it on my digital o-scope ?
3 is my V out just my RMS across my load?


Oh yeah, I was also wondering

When im finding out my RC time constant I know my cap. Value multiplied by my resistance gives me my TC but!! I wasn’t sure if I have to find my capacitance reactance and use it for my resistance when I calculate?

oK but where is shematic?

The bridge rectifier and filter is converting AC to DC. The DC level without ripple, aka no load, is the AC peak value minus the twice the voltage drop across a single diode. With a load, the ripple voltage will be superimposed on top of the DC level. The diodes only conduct for short pulses at the tops and bottoms of the AC waveform. For the remainder of the time, the current to the load is being provided by the filter capacitor. The time during which the capacitor must provide current is 1/2 the period of the AC wave. This time is fixed. If you know your load resistance and you know the max allowable ripple voltage, you can work the RC discharge equation backward to get the minimum filter capacitor size. If you know both your load resistance and the filter capacitor size, you can use the period of the AC wave and the RC discharge equation to determine the ripple voltage.
Capacitive reactance has nothing to do with this discharge equation. You need to use the load resistance.

All the above is an approximation assuming that the ripple voltage is not so large that the diode conduction is a large part of the AC waveform. As the ripple gets larger it becomes a more complex waveform than a simple exponential ramp and the calculations get more difficult.

You can consult the book:

Transistor Circuit Techniques Discrete and integrated, 3rd EditionChapter 9 is what you are looking for.

You can download in this forum.

Good Luck

Hi
If you have an Oscope things are easy.
Just try to measure the output voltage across the load.
You will see a dc voltage.
But if you use the AC coupling of the Oscope (i.e. make the scope read only AC part of the signal) you will see the ripples. Zoom in the scope by changing the V/Div you will see some large ripples.
Ripples are usually measured peak to peak



Hope I have HELPED you