Bridge Rectifier

[Steve Lewinsky]

Im a novice and trying to understand the logics here. My monitor has the
120v AC line coming into a Full bridge rectifier(4 Diode set) with 3 .01
filter caps. Why do I get 183volts DC out the other side and not 120volts
DC?
If a picture is required let me know

 

[JeffM]

Why do I get 183volts DC out the other side and not 120volts DC?

Steve Lewinsky

http://groups.google.com/groups?num...=off&q=jeffm_+"Peak+value"&btnG=Google+Search

 

[Jimmy]

Typically the unloaded output voltage should be 1.414 * RMS input voltage in
your case 120 volts. Sounds like you have a little more than 120.

 

[scada]

Im a novice and trying to understand the logics here. My monitor has the
120v AC line coming into a Full bridge rectifier(4 Diode set) with 3 .01
filter caps. Why do I get 183volts DC out the other side and not 120volts
DC?
If a picture is required let me know

The output of the bridge rectifier should go through some filtering that has
large electrolytic capacitors. The unloaded voltage would be 1.414 * RMS or
1.414 * 120 = ~170 VDC. The fact that you are reading 183 VDC shows that
there is no load on the power supply! Something has open circuited, causing
a no load condition.

 

[Jimmy]

The output of the bridge rectifier should go through some filtering that has
large electrolytic capacitors. The unloaded voltage would be 1.414 * RMS or
1.414 * 120 = ~170 VDC. The fact that you are reading 183 VDC shows that
there is no load on the power supply! Something has open circuited, causing
a no load condition.

The ~170 volts should be the open circuit voltage. 183vdc can only be
accounted for by the fact the input is more than 120 or measurements are
incorrect.