It can be complicated depending on the device that is consuming the power. Passive devices, like resistors (heaters, simple RC filters (also depends on what is downstream of it)) will quadruple their power from 12 to 24 volts. P = V^2/R = Meltdown. Active devices, like a switching power supply, will have the same power at double voltage, but with half the current. So that really means you'll have to ask the manufacturer of the supressor/filter as to how it handles it.audiocontr wrote:im familiar with the applicability (and crutchfield link) when it comes to 12v systems. How do the amperage/wattage ratings change when doubling the voltage?
Looks like the noise filters at Crutchfield seem to be rated for +12V only. But wait, isn't your stereo 12VDC? How about the intercom? That's where you want the noise filter: after the voltage converter (if it's 12V of course). Then if that doesn't work, try re-routing the wires for the stereo (maybe for the power converter, too). Parallel runs of wiring is very good a inducing noise from "noisy" wires. Anything with a coil is going to be noisy when it switches (solenoids, relays, and to a lesser extent fans and motors (depending on the mechanical load)). Anything with AC, too (though probably not a problem in a vehicle). More broadly, anything with a quickly changing current in the wire. Noisy both at the supply and as a radiated field (this is only prevelant in high-current and high-frequency stuff, usually. Spark plugs are a very fast impulse, which is easily radiated).
You may need a tune-up involving resistor-type spark plugs, shielded carbon-core spark plug wires, distributor cap, and coil.
Then if the DC supressor doesn't work, shielding the spark plug wiring. Then if that doesn't work, drink until you can no longer hear it. :idea:
(Parenthetical notation overload)
