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.
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--Myron A. Calhoun.
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PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
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