Looking for simple and reliable voltage doubler 12->24v

[rkremser]

Hello as the topic says i'm looking for a simple design for a 12 to 24 volt
convereter. I have been looking around and realize that there are charge
pumps, transfomer methods and inductor methods to use. When it comes down
to it i need up to .5 amps at the 24 volts and it needs to be reliable and
not sensitive to mechanical vibrations (to be mounted on something similar
to a gocart and run off of the 12 volt system) The smaller the package the
better no more than two cubic inches or so. This will be used to drive two
air solenoid valves for shifting and clutching. Any recomendations are
welcome. I know there are many maxim chips that are very much suitable for
the application but for some reason i feel somewhat hesitant to go the route
of a single IC. thanks in advance

 

[Homer J Simpson]

Hello as the topic says i'm looking for a simple design for a 12 to 24
volt convereter. I have been looking around and realize that there are
charge pumps, transfomer methods and inductor methods to use. When it
comes down to it i need up to .5 amps at the 24 volts

Then you need to use a transformer - preferably with push pull drive.

 

[budgie]

Hello as the topic says i'm looking for a simple design for a 12 to 24 volt
convereter. I have been looking around and realize that there are charge
pumps, transfomer methods and inductor methods to use. When it comes down
to it i need up to .5 amps at the 24 volts and it needs to be reliable and
not sensitive to mechanical vibrations (to be mounted on something similar
to a gocart and run off of the 12 volt system) The smaller the package the
better no more than two cubic inches or so. This will be used to drive two
air solenoid valves for shifting and clutching. Any recomendations are
welcome. I know there are many maxim chips that are very much suitable for
the application but for some reason i feel somewhat hesitant to go the route
of a single IC. thanks in advance

As your air solenoids presumably wouldn't require a regualted 24V, you may find
this off-the-shelf unit meets your requirements (unless you have compelling
reasons to build your own).

http://www.kemo-electronic.com/en/module/m029/index.htm

 

[John Barrett]

Hello as the topic says i'm looking for a simple design for a 12 to 24
volt convereter. I have been looking around and realize that there are
charge pumps, transfomer methods and inductor methods to use. When it
comes down to it i need up to .5 amps at the 24 volts and it needs to be
reliable and not sensitive to mechanical vibrations (to be mounted on
something similar to a gocart and run off of the 12 volt system) The
smaller the package the better no more than two cubic inches or so. This
will be used to drive two air solenoid valves for shifting and clutching.
Any recomendations are welcome. I know there are many maxim chips that
are very much suitable for the application but for some reason i feel
somewhat hesitant to go the route of a single IC. thanks in advance

I have some 24v hydraulic valves that work just fine at 12v -- so just for
grins -- try tripping the solenoid on 12v -- its just an electromagnet and
may pull suffciently to operate on the lower voltage

 

[PeterD]

I know there are many maxim chips that are very much suitable for
the application but for some reason i feel somewhat hesitant to go the route
of a single IC. thanks in advance

Use the Maxim solutions. THey are the best possible solution. Sure,
you could 'roll your own' with discrete components, but that's the
hard way, will be less reliable, and probably be *much* larger in the
end.

 

[Ken Smith]

Use the Maxim solutions. THey are the best possible solution. Sure,
you could 'roll your own' with discrete components, but that's the
hard way, will be less reliable, and probably be *much* larger in the
end.

I assume you work for Maxim.

The OP can get a DC-DC convert from almost anyone else for the job. Look
in Digikey.

 

[rickman]

Use the Maxim solutions. THey are the best possible solution. Sure,
you could 'roll your own' with discrete components, but that's the
hard way, will be less reliable, and probably be *much* larger in the
end.

Sure rolling your own may be more work, but I doubt that it will be
any larger and is ,in fact, likely to be smaller. I have done a
number of PS designs and they mostly were smaller than off the shelf
designs, also cheaper. But the work is not trivial, even with a
design example. In automotive apps (not sure how similar go-carts are
to autos in this regard) you need a lot of input protection way beyond
anything you see in other environments. Unless a module is designed
for that it is likely to fail at a high rate. This applies to both
bought modules and self designed ones.

 

[jasen]

Then you need to use a transformer - preferably with push pull drive.

huh? a charge pump needs push-pull but no transformer.
and a boost converter needs only a single ended drive on the inductor

 

[Homer J Simpson]

huh? a charge pump needs push-pull but no transformer.
and a boost converter needs only a single ended drive on the inductor

for 12 W?

 

[jasen]

for 12 W?

sure.

Bye.
Jasen

 

[rickman]

for 12 W?

You can use a diode to replace the the other transistor. You actually
don't need a transformer, just a coil. The coil is between the
battery voltage and the load with the diode in series after the coil.
The transistor pulls the coil-diode connection to ground long enough
to put enough current into the coil, then it releases. While the
transistor is turned on, the diode is reverse biased. When the
transistor opens up the coil field collapses and the voltage on it
reverses boosting the output voltage. With this wiring the coil
voltage adds to the battery voltage. A controller modulates the pulse
width of the transistor drive in order to maintain a set output
voltage.

These circuits are not hard to understand, but they are closed loop
feedback controllers and attention must be paid to all the details.
So it would be easier to use one off the shelf or to change the
solenoids to work on a 12 volt drive.