"Rightrik" wrote in message
...
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


These relays will usually hold in fine on 12 VDC they may even work OK. If
they will not work there is a circuit that charges a capacitor to 12vdc and
when the relay is energized the cap is momentarily in series with the 12
volt supply. This will pull the relay in then the 12 volts should be enough
to hold it. Google on "operating 24 volt relays on 12 volts" Circuit is very
simple if you can find it.One advantge of using this circuit is that the
relay coils are not stressed as much. A coil that runs hot at 24 may be
cool to the touch on 12.

On Tue, 10 May 2005 20:41:10 GMT, "Jimmie"
wrote:

These relays will usually hold in fine on 12 VDC they may even work OK. If
they will not work there is a circuit that charges a capacitor to 12vdc and
when the relay is energized the cap is momentarily in series with the 12
volt supply. This will pull the relay in then the 12 volts should be enough
to hold it. Google on "operating 24 volt relays on 12 volts" Circuit is very
simple if you can find it.One advantge of using this circuit is that the
relay coils are not stressed as much. A coil that runs hot at 24 may be
cool to the touch on 12.

You might want to check this.

I have dealt with circuits which "should have" worked, but enough
components pulled down the voltage to where relays would not stay
energized, and would rapidly cycle as they struggled to stay
energized.

Happy trails,
Gary (net.yogi.bear)
--
At the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

Yes, i've seen this "pump-up" circuit but i would prefer a real 24 vdc to
make sure the rele is correctly energized.
My 26 vdc - 4 ways Dow-Key coax rele works also with 12 vdc, but the problem
is : "is it affordable at this coil voltage???"
A stronger 24 vdc would be better...

Thank you,
73 de Riccardo IK5WQO