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DIY Stompboxes => Building your own stompbox => Topic started by: Kaiowas on July 17, 2004, 01:25:43 AM

Title: Power Supply question
Post by: Kaiowas on July 17, 2004, 01:25:43 AM
Hi!

I made a power supply for tube circuits (low voltage, from 1.27 to 15.50), i'm using LM317 and LM337, but i would like to dropdown the input DC voltage to the regulators from 33V to..say what? 24V?...so the ics would have a better current response, so, how do i drop this voltage down (not a fancy or expensive thing, just need to enter about 24V to the ICS and they would regulate the output voltage)?

Thanks!
Title: Power Supply question
Post by: niftydog on July 18, 2004, 06:56:09 PM
how is the input DC generated?
Title: Power Supply question
Post by: Kaiowas on July 18, 2004, 08:40:31 PM
Hi niftyDog!

The AC, "reduced" voltages come from the transformer and then go to a rectifier bridge and then they go to a pair of 4700uF and then enter the regulators
Title: Power Supply question
Post by: niftydog on July 18, 2004, 09:00:30 PM
the absolute best way would be to get a transformer with a smaller ratio.

anything else you do is gonna be wasting energy and could potentially generate a lot of heat as well.

You might consider a voltage divider, but there's a lot of pitfalls to consider first. Do you know how much current the power supply is expected to provide?

Quoteso the ics would have a better current response

what exactly do you mean by this?
Title: Power Supply question
Post by: Kaiowas on July 19, 2004, 12:39:29 PM
i found another transformer that helped me a lot more than this one...

anything else would be problematic...

Thanks niftydog!