ok, I drive for a living. Rigs. I hate wires. But there is a need to be comfortable when driving 11 hours a day. I have a gps, ipod and sirius radio that i want to hardwire to the fuse box to eliminate plugging everything in a cigarette lighter. I plan to use 'add a circuit'. My problem is, how do i determine what size fuse to use for each of these? FYI, I know nothing about how to convert Watts to Amps etc, etc...
What I do for many of my customers is to add a cigarette lighter socket under the dash and plug in the device under the dash. The reason is that many of these devices operate on 5-volts, not 12. The step down transformer is built into the cigarette lighter plug in. Hard wiring is not recommended for this reason. The Ipod does work on 5-volts, as do most Sirius tuners.
You cannot convert watts to amps, since watts are power and amps are coulombs per second (like converting apples to miles). If you have at least least two of the following three: amps, volts and watts then the missing one can be calculated. Since watts are amps multiplied by volts, there is a simple relationship between them. The conversion of Watts to Amps is governed by the equation Amps = Watts/Volts For example 12 watts/12 volts = 1 amp The conversion of Amps to Watts is governed by the equation Watts = Amps x Volts For example 1 amp * 110 volts = 110 watts The conversion of Watts to Volts is governed by the equation Volts = Watts/Amps For example 100 watts/10 amps = 10 volts The conversion of Volts to Watts is governed by the equation Watts = Amps x Volts For example 1.5 amps * 12 volts = 18 watts The conversion of Volts to Amps is governed by the equations Amps = Watts/Volts For example 120 watts/110 volts = 1.09 amps The conversion of Amps to Volts is governed by the equation Volts = Watts/Amps For Example, 48 watts / 12 Amps = 4 Volts
