Lowering PS Voltage

[id 10 t]

Hello,
I have the parts lying around to build a 35VDC power supply ( 24VAC transformer + Bridge + Cap). What can I do to lower the voltage to around 30VDC so I can safely power a Xylotex board?
Thanks.
Colin

[H500]

Unwind a few turns or put several diodes between the bridge and cap.

[smarbaga]

with the diode methode u can fine tune your voltage under load as well
approx 0.75 volts drop per diode.

[CLaNZeR]

Well you got your transformer knocking down the ac to 24Volts and as you have found the Bridge Rectifier has taken that and given you your DC voltage but knocked it upto 35/37volts as it tends to.

So now you just need to pop a voltage regulator in after the Bridge Rectifier to knock it down from DC 35V to 30V.

Make sure you use a Voltage Regulator that will supply enough current for your board and make sure you put a nice heatsink attached to keep it cool.

Regards

Sean.

Originally Posted by id 10 t Hello, I have the parts lying around to build a 35VDC power supply ( 24VAC transformer + Bridge + Cap). What can I do to lower the voltage to around 30VDC so I can safely power a Xylotex board? Thanks. Colin