DC to DC Converters

It basically depends on the amount of current to be used from the ckt. In case of a few milliamps, the simple ckt would be to add a current limiting resistor in series and after the resistor to add a zener of reqd voltage in parallel i.e. across. in case of higher current use a transistor in series with the collector to the source side and emitter to load side with a zener of reqd voltage connected between the base of transistor and the other limb.

In addition to the above, voltage regulating chips are available that will operate at a high efficiency.

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6869802 (usual disclaimer)

http://cr4.globalspec.com/thread/45769

Here's a SOLA dc-dc power supply; 20-72vdc in / 5vdc out. Happy Friday!

http://www.solahevidutysales.com/pdf/powersupplies/scd.pdf

I have a hot relationship with the TL494 PWM IC. They are easy to get and if you cant buy one, rip one out of an old ATX power supply. They are as versatile as your missus and will never give up the ghost.

Have a look at the TL494 PDF datasheet from Motorola and scroll down to figure 21...awesome and versatile. Says a max of 4ovdc input...but 48vdc is fine with a few simple mods.

hi you can use SG3524 or SG3525 which are readily available. these chips are quite reliable. the application data is available from Texas insts, Philips, SGS Thomson and motorola.

seetharaman

http://www.datasheetcatalog.org/datasheets/1150/487416_DS.pdf

http://www.datasheetcatalog.org/datasheet2/0/01lp6edfcle40cz717pt0wpy97fy.pdf

You could use a LM2574HVT - 5, also available in the fixed outputs of 3.3, 12 and 15 Volts. Only need 5 components to make it go, will happily supply 500mAmps at 5 Volts from a supply of 60volts dc in the HV version.

http://www.national.com/mpf/LM/LM2574.html#Overview

http://www.national.com/ds/LM/LM2574.pdf

I use these and the general NS switchmode family with great success almost as easy as using a three terminal regulator. And yes you can build them on vero board, I do that for fast prototyping , you just gotta be a little neat..