Mirage mx keeps blowing fuse

2 amp fuse?

start with a 5 amp or 7.5 amp

 

I use a 7.5 in all my export radios.

 

Don't, you're consuming 10 to 20 watts while using 18 or 20/22 gauge wire, with a duty cycle less than 20%, so you are very safe.

 

Who told you to use a 2amp fuse? Any time you key your mic that fuse will be history. 5amp minimum, preferably even 10. If you have a serious short that 10 amp will blow instantly.

Before anyone complains about jumping the fuse size up to prevent a fuse popping, the Tripac in my truck has a service bulletin that came out that said to increase one of the fuses from a 20 to a 25 amp. Doing so stops it from repeatedly blowing the fuse that runs the condenser fan outside the cab and that fan routinely runs for HOURS at a time on hot days without ever cutting off.

I wouldn't jump from a 5 to a 30, but from a 20 to a 25 is fine, from a 5 to a 10 is fine. You would have to have micro small wires to overheat them keying a CB for a few seconds to flap your gums.

I'm glad you got it worked out. See why when you describe problems to people, EVERY LITTLE DETAIL matters? Had you just said "It blows the fuse" NOBODY would have thought you meant a TWO AMP FUSE on a CB circuit. We'd have been chasing our tails trying to help you.

Remember this little formula:



So plugging in your numbers, on a 50W radio that draw a couple more to run the board and speaker, lets say it's 55w. And volts is 12. So 55/12= 4.58amps. So when you key your mic, you're drawing 4.5amps. A 5 amp fuse is VERY close to popping. A 10 would be safer. If you have the volume up real high and key the mic, you could pop the 5amp fuse.

This would also explain why, should you want to run an AMP say, pushing 500w, you do 500/12 and you're looking at 42amps. That's a big fat fuse. You can also figure out how many amps your inverter is pushing out using the same triangle. Let's say you have a 2000w inverter. Well, 2000w/12v=167amps. So your inverter is supplying you with 167amps of power at 12v. However, it's not giving you 12v, it's giving you 120. So 2000/120=17 amps. So if you care to figure out what your inverter is giving you in amps like you know inside your home, it's 17 amps at 120v AC.

I know it's technical. I learned this in trade school, I found it fascinating.

This formula works for everything, AC or DC, 12v, 120, 240v whatever.

Oh, and one other thing, if you notice in the formula, the more volts you have, the less amps you have. Well, wire size is determined by amps, not volts. This is why those small power lines can carry power to so many homes. (I was told by a pilot it's also why airplanes are 24v, because they can use smaller wires and in a plane like a 747, with 170 miles of wire, that is a substantial weight savings) Because they're shoving 15Kv through those lines, so the transformer on your pole kicks that 15kv down to 220v for your house. That means you have massive amps available at the lower voltage. However, your electric bill, if you notice, is actually calculated based on how many watts you use. (your electric meter at your home is really just a glorified watt-meter. In fact, your bill is shown in KWH, or kilo-watt hours. There are those pesky watts, again.) That's determined by the voltage available. So in theory, if your house could handle 15kv, your electric bill would be extremely low because your wattage use would be very low. But since your electric appliances would explode with that much voltage, it's stepped DOWN to 120 or 220v. This means the watts (and amps) that you need to use go WAY up. That jacks your electric bill up.

Kinda sucks, but it is what it is. 15kv is so dangerous inside a consumers home. If a kid sticks a screw driver into a socket with 15kv it would literally blow their arm off.

I have a question posed to me back in electrical class. See how many of you get it right.

Which voltage is most dangerous to humans, and why?

A. 120v
B. 220v
C. 440V

 

The OP said that they used the existing power wires that was in the truck, which since these wires are for a cb radio, it probably already had a 2 amp fuse. I doubt anyone told him or her to use a 2 amp fuse, but who knows.

 

Which voltage is most dangerous to humans, and why?

A. 120v
B. 220v
C. 440V

The answer depends on the circuit. Is the load in resistance or wattage? If the circuit uses a light bulb, the current will decrease with higher voltage.

 

Nope. That is not correct. The question is posed in its simplicity and its entirety.