k7elp60 said:The rule of thumb for linear power supplies is 3000uf per amp. The peak voltage across the capacitor in a full wave rectifier will be 1.414 times
the rms, or 28.28 volts. Another thing to consider is that because of charging current in a typical full wave rectifier circuit one should only plan on getting 0.566 X the rated current of the transformer with out overheating the transformer.
Philipc said:Thanks everyone for your input.
k7elp60 said:The rule of thumb for linear power supplies is 3000uf per amp. The peak voltage across the capacitor in a full wave rectifier will be 1.414 times
the rms, or 28.28 volts. Another thing to consider is that because of charging current in a typical full wave rectifier circuit one should only plan on getting 0.566 X the rated current of the transformer with out overheating the transformer.
Does this mean the rectifier is that inefficient?
Russlk,
I'm using a bridge
Another thing I noticed while playing around, without the filter cap, voltage reads something like 16v, and with cap it reads something like 21v. Numbers are for example only, but is this because the AC ripple is counteracting the DC volts. And this question might be even crazier, but if I had a DMM that could read AC in mv, could I put this on the DC side of the rectifier to measure ripple?
Thanks again for your help.
Philip
Philipc said:Nigel Goodwin
I also have a KHz reading on my DMM, could this also be used to look at the ripple. I have yet gotten to the theory classes yet, just my maths and sciences, so my electronics knowledge is very limited, so please forgive my ignorance.
Philipc said:I was thinking with the right cap, the ripple would go away, and I could use the meter to prove that? Or will the ripple always be there?
Also can you tell me more about the DC blocking capacitor?
Thanks
Philip
Philipc said:I hope you don't mind all these questions, but if a cap is two parallel plates, then why would there be a positive and negative marked on them.