Rectify AC Voltage to 160VDC | Ivan's Electrical Project

  • Thread starter Thread starter darik
  • Start date Start date
  • Tags Tags
    Ac Voltage
AI Thread Summary
To build a 160VDC power supply from 114VAC, a bridge rectifier can be used, but it may initially output around 107VDC due to voltage drops. The peak voltage of 114VAC is approximately 161.22V, which can be achieved by multiplying the AC voltage by the square root of 2, minus diode drops. Connecting the center-tap windings and rectifying each 57V separately could yield the desired output, although significant voltage drops from the diodes will occur. A large capacitor is necessary to stabilize the output voltage, as it will charge to the peak voltage and can briefly show 160V before dropping. Proper precautions should be taken due to residual voltage on the capacitor after disconnection.
darik
Messages
2
Reaction score
0
Hello,

I'm trying to build a 160VDC PSU and need some help rectifying 114VAC to 160VDC.

OK, first I'm in Ireland and the voltage here is 220V/50Hz.
The information given on the label of the transformer that I have is 3300watt 110v Center-Tapped to Earth - 2 x 16amp.

There are two wires connected to the transformer core and then earthed(center-tap) and two end wires.
The output measured from the ends is 114VAC and measured from the center tap to either side is 57 V so I guess the polarities of both ends are opposite each other +/- 57-0-57.

I was considering the circuit found here: http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/rectct.html but I can't find reasonably priced diodes here in Ireland. On the other hand, I have some bridge rectifiers rated 35A 400V.

If I connect a bridge rectifier to both ends the output is 107VDC? Can someone explain way?

So my question is:
Is it possible to disconnect both center-tap windings - rectify each 57v using bridge rectifier - and connect them back together in series to get 150-160VDC. I know there will be big voltage drop because of the two bridges used.

I'll be thankful for any help, advice, or hint you may provide.

Ivan
 
Last edited:
Engineering news on Phys.org
Most meters will have a problem measuring a time varying DC output.
If you put a capacitor on your bridge rectifier it will charge up to the peak voltage.

Warning the capacitor will still have voltage on it when you unplug the transformer.

How big a capacitor you will need for your PSU need depends on how much current you need to supply.

What is the peak voltage for 114vac?
 
Quick and dirty method of finding the peek voltage on line AC voltage is by multiplying the AC voltage by the square root of 2.

This will give you 161.22 minus the voltage drops of you diodes (somewhere around .6V) for 114VAC. Throw a capacitor on the rectified voltage and there you have it 160 +- VDC
Be careful :smile: cheers!
 
Hi,

NoTime said:
Most meters will have a problem measuring a time varying DC output.
If you put a capacitor on your bridge rectifier it will charge up to the peak voltage.

I've disconnected the tap from the ground.
When I measure the rectified voltage I can see 160V for a part of a second and than the voltage drops to 104V. I'll have to find a big capacitor and see what will happen.

Thanks for the advise.
 
I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
Thread 'Electromagnet magnetic field issue'
Hi Guys We are a bunch a mechanical engineers trying to build a simple electromagnet. Our design is based on a very similar magnet. However, our version is about 10 times less magnetic and we are wondering why. Our coil has exactly same length, same number of layers and turns. What is possibly wrong? PIN and bracket are made of iron and are in electrical contact, exactly like the reference design. Any help will be appreciated. Thanks. edit: even same wire diameter and coil was wounded by a...
Thread 'Beauty of old electrical and measuring things, etc.'
Even as a kid, I saw beauty in old devices. That made me want to understand how they worked. I had lots of old things that I keep and now reviving. Old things need to work to see the beauty. Here's what I've done so far. Two views of the gadgets shelves and my small work space: Here's a close up look at the meters, gauges and other measuring things: This is what I think of as surface-mount electrical components and wiring. The components are very old and shows how...
Back
Top