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DIY Stompboxes => Building your own stompbox => Topic started by: MattAnonymous on May 16, 2005, 11:18:01 AM

Title: OT: Converting from 12v to 24v
Post by: MattAnonymous on May 16, 2005, 11:18:01 AM
Hey here's another OT question from me.  I'm working on a gas saving device that uses a float switch and solenoid valve, but both work at 24v and the car runs at 12v.  I've done some searching, but haven't found anything specific to those voltages.  I was hoping that you guys could point me in the right direction.  If you guys can point me to a forum that deals with general electronics, please do.  I'll, then, save this forum for my FX posts.

Thanks,
Matt
Title: OT: Converting from 12v to 24v
Post by: nelson on May 16, 2005, 11:43:43 AM
wouldnt the charge pump over at geofex be able to double 12v to 24v?

sure someone will provide the link.

there is a link under power supplies or something at GGG
Title: OT: Converting from 12v to 24v
Post by: phillip on May 16, 2005, 01:46:34 PM
I probably wouldn't try it with a MAX1044.  The data sheet recommends a maximum input voltage of 10V and a pretty small input current.

I don't think there are any charge pumps that would be able to handle the kind of current that you'd need.

Phillip
Title: OT: Converting from 12v to 24v
Post by: TheBigMan on May 16, 2005, 04:18:52 PM
I know the ICL7660S charge pump can handle a 12V input and gives just under 23V output, but I doubt it would be able to handle the kind of current you'd need.  I might be wrong though, the datasheet is online at the Intersil website IIRC.  I started using them because they're easier to source in the UK than MAX1044s and have the same pinout and boost option.
Title: OT: Converting from 12v to 24v
Post by: cd on May 16, 2005, 04:38:46 PM
Forget about using a 1044 or 7660.  Google around for voltage doublers (buck & boost), if you need lots of current you can use an inductor based one.  I don't have the links handy but there's tons of them out there.  Since you're not dealing with audio frequencies, your options open up immensely.
Title: OT: Converting from 12v to 24v
Post by: cd on May 16, 2005, 04:53:55 PM
Here's a link to get you started:

http://www.hills2.u-net.com/electron/smps.htm
Title: OT: Converting from 12v to 24v
Post by: MartyMart on May 16, 2005, 05:38:40 PM
Quote from: cdForget about using a 1044 or 7660.  Google around for voltage doublers (buck & boost), if you need lots of current you can use an inductor based one.  I don't have the links handy but there's tons of them out there.  Since you're not dealing with audio frequencies, your options open up immensely.

cd, could I safely get 18v from a 9v supply with the MAX1044 as per the
article ?
I need 18v for an Ibanez Flanger which EATS 2x batteries !!  :shock:
Also for a Mutron III+ so it will be in its own small enclosure.....

Thanks,
Marty.
( sorry for the hi-jack ! )
Title: OT: Converting from 12v to 24v
Post by: cd on May 16, 2005, 05:45:37 PM
Quote from: MartyMart
Quote from: cdForget about using a 1044 or 7660.  Google around for voltage doublers (buck & boost), if you need lots of current you can use an inductor based one.  I don't have the links handy but there's tons of them out there.  Since you're not dealing with audio frequencies, your options open up immensely.

cd, could I safely get 18v from a 9v supply with the MAX1044 as per the
article ?
I need 18v for an Ibanez Flanger which EATS 2x batteries !!  :shock:
Also for a Mutron III+ so it will be in its own small enclosure.....

Thanks,
Marty.
( sorry for the hi-jack ! )

Depends what your current needs are.  IIRC a 1044 can output 20mA.  If you need more than that, you'll have to parallel two 1044s, or try a different circuit.
Title: OT: Converting from 12v to 24v
Post by: aron on May 16, 2005, 05:49:41 PM
I tried looking around but I couldn't find anything appropriate.
Title: OT: Converting from 12v to 24v
Post by: MattAnonymous on May 16, 2005, 07:26:18 PM
Thanks for the info guys.  I got the stuff in today and hooked up a universal dc converter.  They actually only need about 9v so I think I should be fine.  I was surprised, though, that there isn't much out there that will double the 12v.

Thanks again,
Matt
Title: OT: Converting from 12v to 24v
Post by: niftydog on May 16, 2005, 07:33:53 PM
try this DC-DC converter (http://www1.jaycar.com.au/productView.asp?ID=KC5358&CATID=&keywords=dc+dc+converter&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=) kit (which is basically a fancy-shmancy switch mode power supply)

There should be other similar products out there.

You find them in the funniest places... I found a 5-9V DC-DC converter on an old Intel LAN card at the local junk recyclers!
Title: OT: Converting from 12v to 24v
Post by: TheBigMan on May 16, 2005, 08:09:36 PM
Quote from: MartyMart
Quote from: cdForget about using a 1044 or 7660.  Google around for voltage doublers (buck & boost), if you need lots of current you can use an inductor based one.  I don't have the links handy but there's tons of them out there.  Since you're not dealing with audio frequencies, your options open up immensely.

cd, could I safely get 18v from a 9v supply with the MAX1044 as per the
article ?
I need 18v for an Ibanez Flanger which EATS 2x batteries !!  :shock:
Also for a Mutron III+ so it will be in its own small enclosure.....

Thanks,
Marty.
( sorry for the hi-jack ! )

You can indeed.  The whole reason I first checked out the ICL7660S (Maplin sell them pretty cheap) was to put a charge pump into an old Ibanez FL-301.  Works fine too.  There's a vero layout in my gallery for a voltage doubler.