Diode Sizing

[ibwev]

View attachment 67594

I am trying to design a circuit that is supplied by 24VAC that goes through a choke, capacitors and then a Wheatstone Bridge arrangement of diodes to alter the 24VAC to Direct Current. The load will pull 430 mA max at 5 volts.

Should I choose the diode size by the amount of rectified current or by the forward voltage @ maximum current?

 

[chemelec]

Buy a 1N4001 Diode.
It is Rated 1 amp and 50 Volts, maximum.
A VERY COMMON General Purpose Diode.

 

[JimB]

Just to add to what Chemelec said,

Any of the diodes in the 1N400x series will work well.
The other diodes in the series 1N4002/3/4/5/6/7 are rated for higher voltages but will work just as well.

JimB

 

[Mr RB]

I just buy 100 or 500 quantity bags of 1N4007 diodes, most of the larger hobby elec suppliers sell bag quanitities of the common diodes. As the 4007 is good for 1000v you can just use that diode in anything and don't need to stock the lesser diodes (as JimB said) and of course you get quantity discounts and the comfort of knowing you always have a heap of good diodes on hand when you go to make something.

 

[kubeek]

View attachment 67594

I am trying to design a circuit that is supplied by 24VAC that goes through a choke, capacitors and then a Wheatstone Bridge arrangement of diodes to alter the 24VAC to Direct Current. The load will pull 430 mA max at 5 volts.

Should I choose the diode size by the amount of rectified current or by the forward voltage @ maximum current?

That would be a bridge rectifier, Wheatstone bridge is something different.

 

[ibwev]

That would be a bridge rectifier, Wheatstone bridge is something different.

Thank you for the correction. I was trying to follow the steps from https://www.ehow.com/how_7416365_rectify-115-ac-dc.html. Step 2 labels it a Wheatstone Bridge.

 

[JimB]

I noticed the expression "Wheatstone Bridge" and assumed that it was just a bad translation of "bridge rectifier" by the OP from some other language into English.

That such an error should appear in an article presuming to teach how to rectify AC ot DC is a bit disturbing.

JimB