Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 I removed an old CCTV power unit at work today and just happen to notice that it converts 240v ac to 12 v dc. I'm wondering if this could be used in the shed/obs for powering my NEQ6/ Due Heater / Remote Focuser ect ect it has 9 individual fused 12v outputs.. each are 4 amp. Any Good???? 20150805_125923 by Steven Whatley, on Flickr 20150805_125940 by Steven Whatley, on Flickr Link to comment Share on other sites More sharing options...
Sheila Posted August 5, 2015 Share Posted August 5, 2015 are you sure it goes to 12V not 24V??? Johnnyaardvark 1 Link to comment Share on other sites More sharing options...
Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 it can be set to 6/12v @4amps or 24v @2amps so the label on the inside says.. Link to comment Share on other sites More sharing options...
Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 it can be set to 6/12v @4amps or 24v @2amps so the label on the inside says.. 2015-08-05_02-37-35 by Steven Whatley, on Flickr Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted August 5, 2015 Share Posted August 5, 2015 Looks like the output from the main transformer is 24V ac. What's the electronics on the right doing? Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted August 5, 2015 Share Posted August 5, 2015 Beat me to it. Wondered if there may be a potentiometer in there and there is. I think it looks like it would work but I am sure others who know better than I can comment on whether or not it is the most efficient way and if the smoothed rectified ac would be suitably regulated. Link to comment Share on other sites More sharing options...
Perkil8r Posted August 5, 2015 Share Posted August 5, 2015 4 amps will be a bit low for the mount when slewing. To get around this you can use two outputs in parallel to get a higher current draw in theory. Link to comment Share on other sites More sharing options...
Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 cool I will wire up and try a few bits out before I stick my mount anywhere near it Link to comment Share on other sites More sharing options...
Sheila Posted August 5, 2015 Share Posted August 5, 2015 (edited) 4 amps will not be enough i dont think, assuming you have dew heaters, focuser, any camera?? I actually use a bench unit, its much easier, 240v, 12volt output up to 30 amps i think run everything off that has cigarette lighter sockets and direct connect ones. you will have something drop out or worse if its only 4 amps Edited August 5, 2015 by Sheila Link to comment Share on other sites More sharing options...
Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 ah ok Sheila... I'm no electronics expert but just wondering if it would be 4amps per channel or 4 amps overall??? Thanks Link to comment Share on other sites More sharing options...
StuartJPP Posted August 5, 2015 Share Posted August 5, 2015 The transformer is rated at 100VA (100 Watts) at 24V (st-uv24-w100). 100W / 12V = 4.16A. (likewise 100W / 24V = 2A) That is 4.16A total. It also says it in the text Section 9 part C, which I only discovered after reading it I would have thought that 4Amps would be enough, but the initial inrush current at the point of slewing could be more than this and there could be a voltage drop, depending on the load. Even a well balanced mount will have quite a lot of inertia to overcome until the mount actually starts moving. If you have got a multimeter, make 100% sure that the output voltage is 12V and no more...if you haven't got one, get one, they are cheap and very useful. Johnnyaardvark and Smithysteve 2 Link to comment Share on other sites More sharing options...
Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 (edited) Thanks Stuart... I hooked up a socket to it and plugged in my voltage checker.. it read 12.6v so I hooked up a small 12 lamp and that was fine too.. I bit the bullet and tested the mount fully loaded and it slew fine.. However this was just the mount.. am I right in saying then it couldn't be used to power anything else as it would take amp away from the mount? Edited August 5, 2015 by StevenWhatley Link to comment Share on other sites More sharing options...
Perkil8r Posted August 5, 2015 Share Posted August 5, 2015 Likely hood is yes it will be too much. I am surprised it gave enough to power the mount to be honest. Fully loaded your mount will draw more current too don't forget. I didn't read the instructions you posted just went off your description when I suggested using 2 outputs in parallel, since it is 4.5A overall I would say don't bother, you can buy cheap outdoor lighting transformers off eBay and the such for around £20-30 that will give 20A overall across multiple outlets and they are waterproof too. I plan on using one for my power needs. BAZ 1 Link to comment Share on other sites More sharing options...
Guest StevenWhatley Posted August 5, 2015 Share Posted August 5, 2015 Ah ok.. well maybe some of the electrics can be saved for a future project Thanks for al the advise folks !! Link to comment Share on other sites More sharing options...
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