hello
I have to make power supply analysis using

1 transformer 12vrms
1 bridge rectifier
1 resistor 4.7kohm
4 capacitors 1uf 22uf 47uf and 100uf
1 oscilloscope
1 multimeter

I measured the voltage coming out of the transformer at 20v, secondary
I connected the components and got the following

caps oscilloscope(dc ripple) meter(mean dc)
1uf 17v 20v
22uf 2.1v 26v
47uf 1.4v 27v
100uf 450mv 27v

when I made measurements without the capacitors, using the oscilloscope I got 28v and 21v with the meter across the resistor.

I did use multisim and got 15v for the mean dc with the 100uf cap.

im not to sure what im doing wrong here?

any help would be appreciated!!!

all the best

simon

 

See this site http://en.wikipedia.org/wiki/Ripple_(electrical)

 

what is the transformer model number? or post a picture.