700mA DC max range

** The cable's max amp rating is not directly relevant to distance of the allowable run.

You need to know the cable's resistance per metre and the allowable voltage loss.

Or, just try it out and see.

........ Phil

Thanks for your speedy response Phil. I have put a request into the company who supply the cable, just waiting for an email from them about the impedance. The run needs to be about 200 meters ideally and i'm just concerned that the setup will be dangerous if i use DC voltage.

thanks Again Dan

** Err - so you have no ohm meter ?

** It won't be dangerous at 12 volts - just useless.

You will HAVE to use a higher voltage - preferably AC.

....... Phil

there's no maximum especially if you're prepared to put a more than

12V into one end provide voltage regulation at the camera end

say amybe upto 24V in and a well-heatsinked LM7812 at the camera end we really need to know the resistance of the wire, (or its cross-section, or wire gauge - you want 200m, right?)

Bye. Jasen

I have all the tools, just have not got the cable or power supply yet. if the run is too long wont the cable become hot?

This is basics electronics stuff - Ohm's law: E = I * R. So if your cable's DC resistance is 1.33 ohms, the cable's voltage drop will be 1 volt. This means that if your 12v @750mA supply is at one end of the cable, then only 11 volts will be available at the other (camera) end of the cable. According to Alpha Wire's web site (alphawire.com), 10 awg SOLID wire has a resistance of 3.4 ohms per km. This is 0.68 ohms for 200 meters. The cable's voltage drop is 1.02 volts (400m there and back). This is basically heavy duty house wire, rated for ~30Amps. And still, there is only 11 volts for the camera.

As Phil mentioned, you will need a higher voltage at the non-camera end of the cable, preferrably AC. Move the power supply to the camera end of the cable. Then you can use a smaller cable. Why do you need 200m of cable???

HTH -Dave Pollum

no, because it is long the heat will be dispersed along its length.

for example 20W dissipated by a 200m cable is 0.1w per metre or

1mw per cm.

If the cable is rated for 5A the any current less than 5A should not be an issue.

Bye. Jasen