Rectifier generate 220VDC and 2kW power

[keithkyll]

What's missing is a capacitor. With rectification (diodes) only, you still use the RMS.

 

[Jeff23spl]

Have I missed something here, wont 240VAC full wave rectified give about 310VDC ?

it give yes a peak 310vdc when adding the capacitor but when driving only an electrmagnetic coil....having ripple doesn't matter and he will use the RMS voltage value that will be close to 220 v DC a little bit less with the 1.4 volts usually lost in the diode bridge....

when you put a cap, it raise the voltage unloaded but this voltage will flutuate a lot with the load....it doen't need a regulated power supply here but just DC voltage to charge the coil with electomagnetic flux and i bet it's 220 volts DC +/-10%...

 

[kamenges]

We seem to have a little component selection disagreement between rdrast and Jeff23spl about the size of easily available rectifier modules.

rdrast, do you have a source you commonly use for your rectifier modules?

Keith

 

[Jeff23spl]

Any of these supply both bridge or individual rectifier


http://www.e-sonic.com/acc/home.aspx

http://www.digikey.com/

http://www.alliedelec.com/

 

[zai_jnr]

I have done experiment for rectifier design circuit as per attach file.

When i set input 150 VAC.. I will get 220VDC (without load)... when set 240VAC..the value is more than 300 VDC..what i need to do for this circuit if I want input is 240 VAC and output is 220 VDC

Thank you in advance for your reply..

 

[milldrone]

When i set input 150 VAC.. I will get 220VDC (without load)... when set 240VAC..the value is more than 300 VDC..

Have you tested with the load attached? I would expect the voltage to drop a little below the incoming.

 

[Jeff23spl]

as we said earlier remove your caps and you will read without load close to the desired voltage...Caps aren't needed for your application and it can cause voltage peak problems also....

AC 240 VAC is a sinus of 240 volts RMS and peak at 340 volts when you rectifie it to DC with a cap, the peak voltage have time to charge the cap to 330+vdc because nothing discharge the peak ripple of 340v....But with load it will stabilise very lower

A good exemple is a dimer swtich for domestic light: It doesnt reduce voltage to the lamp but it reduce the duration time the lamp see the max voltage and this give the same effect of lowering watts or the light intensity at lower cost than using a voltage step down auto-transformer...But it work only with standard bulb, if you put a led light it won't work because their is not enought load