Hello, i need a little, low power (about 500 mA) step up converter from 12 v
dc to 24 v dc to operate correctly a 4 ways coaxial switch.
I have found project on the net, but i wonder if there is a ready, little,
not ott expensive kit or ready-to-go-module to obtain this 24-26 v dc
voltage from 12 (13,8) dc volt input.

Thank you,
73 de Riccardo IK5WQO

Rightrik wrote:

Hello, i need a little, low power (about 500 mA) step up converter from 12 v
dc to 24 v dc to operate correctly a 4 ways coaxial switch.
I have found project on the net, but i wonder if there is a ready, little,
not ott expensive kit or ready-to-go-module to obtain this 24-26 v dc
voltage from 12 (13,8) dc volt input.

Thank you,
73 de Riccardo IK5WQO


I think you might find a "wall-wart" power supply for a computer printer
to do the job.

You can find these in voltages like 24-28v @ 1 amp for maybe $10 new in
the US. Of course ours are 120v but I imagine you have the 240v types
available over there in I-land.

-Bill

Rightrik wrote:

Hello, i need a little, low power (about 500 mA) step up converter from 12 v
dc to 24 v dc to operate correctly a 4 ways coaxial switch.
I have found project on the net, but i wonder if there is a ready, little,
not ott expensive kit or ready-to-go-module to obtain this 24-26 v dc
voltage from 12 (13,8) dc volt input.

Thank you,
73 de Riccardo IK5WQO




They are available. There are some for mobile police computers for example.
Also look for a 12 to 12 volt with isolated 12 volt output. You can use
the output in series
with the input to get the 24 volt. And a 12 to 8 or so may be OK as many
relays
will work with less than the full 24 volts.

Good luck.
Bill K7NOM

On Wed, 4 May 2005 23:24:24 +0200, "Rightrik" wrote:

Hello, i need a little, low power (about 500 mA) step up converter from 12 v
dc to 24 v dc to operate correctly a 4 ways coaxial switch.
I have found project on the net, but i wonder if there is a ready, little,
not ott expensive kit or ready-to-go-module to obtain this 24-26 v dc
voltage from 12 (13,8) dc volt input.

Thank you,
73 de Riccardo IK5WQO

KEMO Electronics (germany) make these items. They have an interesting range of
small modules with various functions. Have a look at their web page:

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

They are wholesale only, but have distributors around the planet.

This may be slight overkill (they claim it's good for 100W) but it's
inexpensive:

www.oatleyelectronics.com/kits/k168.html

Alternatively, you could put together something quite simple using
an MC34063A (try Google) - easy to use, readily available.

Bill

"Rightrik" wrote in message

snip
not ott expensive kit or ready-to-go-module to obtain this 24-26 v dc
voltage from 12 (13,8) dc volt input.

Thank you everyone for suggestions !!!

73 de Riccardo IK5WQO

In article , "Rightrik" wrote:

Hello, i need a little, low power (about 500 mA) step up converter from 12 v
dc to 24 v dc to operate correctly a 4 ways coaxial switch.
I have found project on the net, but i wonder if there is a ready, little,
not ott expensive kit or ready-to-go-module to obtain this 24-26 v dc
voltage from 12 (13,8) dc volt input.

Riccardo-

If you have a 12 volt inverter of any kind, you might look at the primary
side of its circuit. If the transformer center tap is connected to 12
volts and it uses switching transistors to alternately connect the ends of
a transformer winding to ground, then you can connect rectifiers from the
ends of the transformer winding, to a filter capacitor for a plus 24 volt
supply.

When one end is grounded, the center is still plus 12 volts, so the
opposite end of the winding becomes plus 24.

73, Fred, K4DII

Hello, i need a little, low power (about 500 mA) step up converter from 12 v
dc to 24 v dc to operate correctly a 4 ways coaxial switch.

If "operate" does NOT mean "hold" (i.e., if you just need pulses of 24 volts)
then you can wire a capacitor to a switch such that the capacitor charges
to 12 volts and then ADDS to that same 12 volts to operate the relay.
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

If "operate" does NOT mean "hold" (i.e., if you just need pulses of 24
volts)
then you can wire a capacitor to a switch such that the capacitor charges
to 12 volts and then ADDS to that same 12 volts to operate the relay.

Well, i need a stable 24 v dc voltage, not just a voltage peak to 24 and
back to 12.

Thank you,
73 de Riccardo IK5WQO

Riccardo-

If you have a 12 volt inverter of any kind, you might look at the primary
side of its circuit. If the transformer center tap is connected to 12
volts and it uses switching transistors to alternately connect the ends of
a transformer winding to ground, then you can connect rectifiers from the
ends of the transformer winding, to a filter capacitor for a plus 24 volt
supply.

When one end is grounded, the center is still plus 12 volts, so the
opposite end of the winding becomes plus 24.

Thanks Fred, but i would like the dc-dc inverter solution to be able to
operate the switch from any 12/13,8 vdc source.

73 de Riccardo IK5WQO