boost 12 to 24

[Thunderchild]

can anybody supply a simple 12 volts to 24 volts converter for like 5 amps ?

 

[Nigel Goodwin]

can anybody supply a simple 12 volts to 24 volts converter for like 5 amps ?

It's not going to be very simple, and it's got to be a switchmode design (obviously), which are notoriously tricky to get working well.

Exactly why do you want this?, and what's it for?.

 

[Thunderchild]

to boost my 12v car battery as i wish to use an amplifier that needs 24 volts and wouldn't mind experimenting with this kind of circuit.
my thought was this like real simple but not practical: have a relay (with two comutators like most have) and have it switching on and off and the relays comutators conected up so that they keep reversing the polarity of the power supply like is often done with a manual comutator in a universal transformer. this will practically generate a square ac of 12 volts that with a rectifier can be made into 24 volts by seperatly rectifying each polarity and putting them in series so in paractice i am actually having two condensers in series being charged alternativly making a total of 24 volts or there abouts. ok so i know this is a crazy idea because the relay will wear out quikly be niosy and not be able to work fast enough meaning battery sized condensers so a transistor solution will be ideal but my last attemp was more like transistor heater i do not think i burnt them out as they did not get that hot and there was no load but something went wrong and probably i was passing 12 volts straight through them all at once getting nowhere. i did this with a pair of npn and pnp transistor like a controlled rectifier bridge. this circuit could be used to make any voltage as a multiplying rectifier can be used to even obtain 220 volts that can feed a pc in the car even if it is 220vdc as the pc power supply need dc anyhow :wink:

 

[Nigel Goodwin]

It's not a crazy idea, just an old crude one - they were commonly used to drive valve radios in cars back in the 1950's, special relays called 'vibrators' were used. Two basic types were available, syncronous and non-syncronous, syncronous ones had extra contacts which rectified the secondary for you.

There are various designs for inverters on the internet, but some of them are too simple to work, and would be nothing but trouble. A good efficient inverter is a fairly complicated device to build!.

 

[Someone Electro]

You may look at National Semiconductor for switchmode PSU ICs.There are sipmple intergrated ones that need litle componnets to work but are low power.Then there are high power ICs that need external MOSFETs and lots and lost of components to work.

Providing that much power will need an prety bulky inverter.

 

[stevez]

Someone Electro mentioned the National Semiconductor approach and I am wondering if anyone has gone in that direction. I perused their site some time ago and it appeared that there was substantial assistance provided with designs including identifying the exact part numbers for things like the inductors. I was left with the impression that this might be a good resource should I want to attempt something like this in the future. Has anyone used the site, found it useful, etc?

 

[Someone Electro]

Yea they have an online simulator for some of there ICs.(I think its called webench)

They also give sampels

 

[ante]

This might give you some ideas, it’s not very complicated to modify for any other output voltage single or double if you like: **broken link removed**