Hello all,
I'm mid flow into a project to power multiple pieces of astronomical equipment using a 75Ah 12V leisure battery and x6 buck/boost DC-DC converters which supply XLR connectors for their outputs and I need some advice on cables.
Here's a rundown on my situation thus far:
The main fuse directly off the battery is rated at 30A (which is about 10A+ more than I should pull) which is wired up with 36A cable to two 100A distribution blocks (one for + and one for -, 100A is a bit overrated but I happened to have these lying around), these in turn use 16.5A cable from the distribution blocks, through 10A fuses on the +, to power the DC-DC converters. The output of each DC-DC also uses cable rated at 16.5A through individual quick blow fuses and outputted to XLR connectors on the case which contains all this stuff.
The output voltages of these converters are adjustable to whatever voltage I require and capable of supporting 10A each ( 7A continuous ) on each output although all outputs wont come even close to pulling this kind of amperage.
Here is a list of the 'Outputs, their required output voltages, quick blow fuse ratings, what their powering and estimated Watt usage:
No 1 - 12V......3A.......12V 7-way USB 3.0 Hub........Not 100% sure of the Watts for this Hub but mains adaptor is rated at 3A, x4 USB inputs are used
No 2 - 14V......4A.......Telescope Mount...................Max 18W at full load
No 3 - 12V......4A.......Astrophotography Camera.....30W absolute max but will pull approx. 12 - 15W under working conditions
No 4 - 12V......1A.......Telescope Focuser.................Manufacturer estimates 5 - 10W absolute max at 12VDC
No 5 - 19.5v....6A.......17" Gaming Laptop................Mains Adaptor rated at 19.5V 6.15A 119W but that's under full load, only approx. 35W was
measured in a test while Laptop was running on internal battery with required software running.
No 6 - Aux.....??.........Spare
Here's my problem:
Each of the above outputs will need a cable to run from the output XLR's to their respective equipment, I need about 3 meters long on each cable. I popped into my local Maplin store and they offered me the following:
http://www.maplin.co.uk/p/twin-core-15a-figure-8-cable-priced-per-metre-xs72p
Not 16.5A but almost there at 15A and well capable of handling the absolute max of 6A as stated above. They also wanted to charge me over £40 for 20 meters of this stuff which was ridiculous to say the least.
After getting home I went on line to get it cheaper but one fact came up which made me a little concerned. I found loads of Figure of 8 twin black & red cable on Ebay like Maplin's have rated at 15 Amps but as you'll see from above I have one output at 14V and one at 19.5v.
Example:
http://www.ebay.co.uk/itm/Twin-Core...hash=item2a07772a4d:m:m4faPioneKjuOm9F73jphOA
Will this cable be a problem if I run 14v and 19.5v down it even though I wont come close to it's 15A rating ???
Many Thanks for any help
Paul
I'm mid flow into a project to power multiple pieces of astronomical equipment using a 75Ah 12V leisure battery and x6 buck/boost DC-DC converters which supply XLR connectors for their outputs and I need some advice on cables.
Here's a rundown on my situation thus far:
The main fuse directly off the battery is rated at 30A (which is about 10A+ more than I should pull) which is wired up with 36A cable to two 100A distribution blocks (one for + and one for -, 100A is a bit overrated but I happened to have these lying around), these in turn use 16.5A cable from the distribution blocks, through 10A fuses on the +, to power the DC-DC converters. The output of each DC-DC also uses cable rated at 16.5A through individual quick blow fuses and outputted to XLR connectors on the case which contains all this stuff.
The output voltages of these converters are adjustable to whatever voltage I require and capable of supporting 10A each ( 7A continuous ) on each output although all outputs wont come even close to pulling this kind of amperage.
Here is a list of the 'Outputs, their required output voltages, quick blow fuse ratings, what their powering and estimated Watt usage:
No 1 - 12V......3A.......12V 7-way USB 3.0 Hub........Not 100% sure of the Watts for this Hub but mains adaptor is rated at 3A, x4 USB inputs are used
No 2 - 14V......4A.......Telescope Mount...................Max 18W at full load
No 3 - 12V......4A.......Astrophotography Camera.....30W absolute max but will pull approx. 12 - 15W under working conditions
No 4 - 12V......1A.......Telescope Focuser.................Manufacturer estimates 5 - 10W absolute max at 12VDC
No 5 - 19.5v....6A.......17" Gaming Laptop................Mains Adaptor rated at 19.5V 6.15A 119W but that's under full load, only approx. 35W was
measured in a test while Laptop was running on internal battery with required software running.
No 6 - Aux.....??.........Spare
Here's my problem:
Each of the above outputs will need a cable to run from the output XLR's to their respective equipment, I need about 3 meters long on each cable. I popped into my local Maplin store and they offered me the following:
http://www.maplin.co.uk/p/twin-core-15a-figure-8-cable-priced-per-metre-xs72p
Not 16.5A but almost there at 15A and well capable of handling the absolute max of 6A as stated above. They also wanted to charge me over £40 for 20 meters of this stuff which was ridiculous to say the least.
After getting home I went on line to get it cheaper but one fact came up which made me a little concerned. I found loads of Figure of 8 twin black & red cable on Ebay like Maplin's have rated at 15 Amps but as you'll see from above I have one output at 14V and one at 19.5v.
Example:
http://www.ebay.co.uk/itm/Twin-Core...hash=item2a07772a4d:m:m4faPioneKjuOm9F73jphOA
Will this cable be a problem if I run 14v and 19.5v down it even though I wont come close to it's 15A rating ???
Many Thanks for any help
Paul