# weird: bridge rectifier boosts voltage WITHOUT capacitor? how?

Discussion in 'The Projects Forum' started by Hamlet, Apr 25, 2016.

1. ### Hamlet Thread Starter Member

Jun 10, 2015
146
4
I have a transformer with 16.02v output A.C.
I put it thru a 35A bridge rectifier, and my voltage reads 20.69 D.C.
The AC ripple is 10.41

Am I missing something? I thought my VD.C. = 0.90 X secondary V A.C.
(14.418v DC)

2. ### Papabravo Expert

Feb 24, 2006
10,338
1,850
Where did you get that formula? It's wrong.
Measuring DC voltage after a bridge rectifier doesn't make a lot of sense so I can't really tell you what to expect. The peak AC voltage out of the transformer into the rectifier is 16.02 * 1.414 = 22.65 volts. Did you forget that AC voltage measurements are RMS (Root Mean Square)? There is no magic here.

Last edited by a moderator: Apr 26, 2016
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3. ### Hamlet Thread Starter Member

Jun 10, 2015
146
4
Sorry, it was a wiring mistake. I haven't been myself lately, thanks.