Topic: Electrics - Volts, Amps and Watts

[[MAF]Sighmoan]

Does anyone know anything about electrics?

I need help.

[MadMax]

a little

[[MAF]Snoopy]

[youtube]http://www.youtube.com/watch?v=2a4gyJsY0mc[/youtube]

[ivanduk]

You got luck, im learning about it at school

[falco355]

watts = voltage X amps , the easier thing i know

[Flopster]

Wow, same-.. I go in 'Tallinna Ehituskool' which is a school that specialises in 'building', learning to be an electrician-.. Boring and lame as shit tho, but ask anything.

Right now on the second year-.. of three

[Larry]

I am only a carpenter dont know much about electricity

[[MAF]PyroFox]

^ So why comment? lol

[Larry]

dont know much about electricity

maybe it's that little thing that i know, that is what he want to know

[[MAF]Snoopy]

i am only an electrician, but i don't know anything about electricity

[[MAF]Epoxi]

You have a captive audience ready to meet your every need...but you haven't told us the problem.  

[b00tsyou]

what's ur problem ? simon

[[MAF]Sighmoan]

Right, i am fitting a car stereo. It is this one. It has 4*45W peak.

My van doesn't have a harness for the stereo, so i have bought this: http://www.maplin.co.uk/Module.aspx?ModuleNo=99497

The van does have stock speakers, with cables running to the dash. I have used an AA battery on these to see if the speakers move, and they do. This means the speakers and cables 'work'. I need to get to the back of the speakers to see their power rating. I'll post that here once i do.

To connect the speaker wires to the harness cables linked to above, i got this. Will this be ok? Is 10 amps enough or suitable?

In the dashboard, there are two wires coming out of the back of the cigarette lighter, a red and a black one. I have tested the red one with a multimeter and it is the ACC switched one. The black one will no doubt be earth, but i am going to earth the harness above to the body of the car.

My main problem is the constant, as i will need to take a power supply from the battery to the stereo.

So, i need to know what kind of cable to use, what Amp/Watt/Gauge cable to use between the battery and stereo. The distance between the stereo and battery is less than 3 meters/10 feet.

The fuse in the back of the head unit is 10amp, so i will also place an inline fuse near the battery just to be safe, which will also be 10amp.

I have bought a 6 metre 8 amp cable for this, but have no idea what gauge it is. Should the amp of the cable match or be higher than the fuse, so that the fuse blows before the cable melts?

[[MAF]Epoxi]

To be honest, I wouldn't worry about the amperage of the cables and fuses, I agree that the rating of the fuse should be lower than the cables (like you said, so they don't melt) but I'm not too bothered. I hardly see why a simple stereo would draw anywhere near 8 amps at a comfortable volume level, so if there's something wrong, odds are it will be more than 10 amps and the fuse will blow anyway.

Just remember to solder your cables (or use screw clips like the one you posted) and seal them with electrical tape when done to stop cables becoming undone or moisture getting in and shorting them.

Edit: This might also be worth a look. http://www.tomshardware.co.uk/forum/53047-33-stereo-amperage
They're saying current draw will be 13A max. even if you blast it to painful levels.

[[MAF]Sighmoan]

To connect the wires i have a crimper to put these on the ends of them (i got male and female).

I got the 5amp red ones, as the red switched cable already had a 5amp female connector on it.

Should i have gotten the blue ones that are 15amp? Or should i at least get some 15amp ones for the constant?

Sounds like i just need to get the inline fuse, the 10amp+ cable and i am good to get started.