load on bridge rectifier

Thread Starter

digitsboy

Joined Dec 29, 2016
48
Hi,

I have the following circuit.
I have an AC input(230VAC) which is converted to DC via a bridge rectifier.
This DC output is connected to a chroma DC load(63204)
1611226030767.png
When I just measure the input voltage at the chroma DC load, the Chroma measures about 327v(230VAC*sqrt(2)) so that is fine!
But when I enable a load(for example 1A constant current), the input voltage I measure on the load is fluctuating a lot.
The display on the load gives a value of about 200-220VDC? I cannot explain why this value is given?

On the AC side I have two outputs. So one I connected to the bridgerectifier/load and the other I connected to a multimeter.
The strange thing is that if I enable the load I measure the strange voltages on the load but the Multimeter is giving steady 230VAC.

So why is the load giving these strange values? Hopefully someone can explain this for me!
 
Last edited:

shortbus

Joined Sep 30, 2009
8,726
More explanation of what your load is, resistor, motor or what? Just a guess but without a capacitor on the DC side it will give fluctuation as the AC side goes through the zero crossing point. Are the measurements you got from a real circuit or a simulation?
 

wayneh

Joined Sep 9, 2010
17,153
You have DC only in the sense of being current in one polarity, but it's still pulsing from zero to 327V. Your load may not be able to deal with that, or it could be a measurement artifact. Add a biggish capacitor across the DC poles.
 
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