How to increase current and maintain voltage

[Cold Fusion]

There is absolutely no way that 20g wire is heavy enough for a 24a load,

the gauge of the cable is awg20 the current for 24v is 24.04A i can't mount battery on the rov.

helpless88-
You need to pass 600W (or so) over conductors that are good for 5A (that's a guess, I don't know what #20 is good for) As has been mentioned:
1. you can't push 24A down a #20 wire for very long before it melts.

2. At 24V, #20 wire, 40meters, the voltage drop wastes a lot of power.

So, you are going to have to get creative. I suspect you are on your way to being an excellent engineer. An rov is a pretty ambitious project.

The problems are physical constraints (wire size, distance, voltage, required power).

Here is an an example of a solution. It appers you want to transfer about 600W of power down your #20 conductors that are good for about 5A. Consider this, transform (inverter) the voltage to 120V or higher if you can - 240V is even better. 3A at 220V is 660W. Consider using 400hz instead of 50hz. At the rov end, put in switching power supplies to develop the three voltages you need.

You need to provide information on your electrical background

No you don't. Your question aren't any worse than some of the others on here. Just keep asking. Some on here will try and help.

cf

 

[gar]

090216=1137 EST

HRLPLESS81:

You need to get some books on basic DC electrical theory and study them.

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[dbuckley]

Just a note that marine ROVs which often have really long supply cables use supply voltages in the thousands of volts range.

You just cant send large currents at low voltages over long distances using sane sized conductors. Something has to give, and voltage is usually the easiest.

 

[Jraef]

Just a note that marine ROVs which often have really long supply cables use supply voltages in the thousands of volts range.

You just cant send large currents at low voltages over long distances using sane sized conductors. Something has to give, and voltage is usually the easiest.

Yep, I just worked on a system for an undersea ROV, they step up to 3300VAC for the umbilical, then step back down again to 240VAC to feed the DC power supplies for the servos and controls at the ROV. But that umbilical is upwards of 3000' long and besides, working with Medium Voltage like that is not to be undertaken by amateurs.

For 40 meters you don't need anything so drastic, but the suggestion for using 240VAC is the way to go. You can get small inverters for Solar PV systems that do essentially just what you need at the Source end, then you just need a standard 40A 240VAC to 24VDC power supply at the ROV end (they only make them 20A and 40A off the shelf).

 

[LarryFine]

(they only make them 20A and 40A off the shelf).

Who is "they" that nobody in the world makes one between?

 

[gar]

090217-0851 EST

Larry here is support for your question.

In post #6 I referenced
www.us.tdk-lambda.com/lp/ftp/Specs/vega.pdf

Look at the specifications. There is one output module for 24-28 V at 25 A, another at 20-24 at 27 A.

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[Jraef]

Who is "they" that nobody in the world makes one between?

COTS power supply manufacturers.
But sorry, I was wrong. I was looking at industrial grade power supplies, which range from 480W (20A) to 960W (40A) from people like Sola, Puls, Phoenix etc. (and yes, a different division of Siemens, who I now work for). But there are some chassis mount commercial grade 750W (31.5A) units out there. I don't know if I would put a commercial grade power supply on a moving, vibrating ROV though, they are typically designed to be used in labs or on work benches.