wangsoft Posted February 7, 2006 Report Share Posted February 7, 2006 Hi there! I'm wondering where I could get a transformer to step up 12V DC to 115V DC. I can't seem to find anything off-the-shelf, and I don't think I have the ability/expertise to make my own. I'm planning to power a set of 4 115V DC motors with a 12V lead-acid battery. BTW as a rough estimate, a 12V 7Ah motorcycle battery should be able to power 4 25W 115V motors for 7*115/25/4 = 8 hours right (assuming voltage was stepped up so it could actually run the motor)? Thanks! Quote Link to comment Share on other sites More sharing options...
MP Posted February 7, 2006 Report Share Posted February 7, 2006 A transformer will not step up DC. You must first convert it to AC with some sort of charge pump circuit. You want to convert your DC to an AC voltage; Use a transformer to multiply it, then rectify the voltage to DC. MP Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 7, 2006 Report Share Posted February 7, 2006 Your motors need 100W. The inverter will heat with about 20W. A little 7Ahr battery can power 120W from 12V only 2/3 of an hour or less. It is 10A from the little battery. Quote Link to comment Share on other sites More sharing options...
wangsoft Posted February 8, 2006 Author Report Share Posted February 8, 2006 Hey thanks guys. The parts I'm looking at are listed below. I'm wondering if there is actually anything that converts 115VAC (output from the power inverter) to 115VDC. Or is there an inherent loss of voltage when you go from AC to DC? I can't find anything that goes 115VAC to 115VDC. I just assumed the motor runs off DC, but do you think the "115V" description in the motor actually means 115VAC, and then convert that to DC, which will be lower voltage (max DC voltage I find in off-the-shelf converters is 42VDC)? Thanks again.This is the motor: http://www.princessauto.com/moreinfo.cfm?TAG=38242&SCAN=CANThis is the power inverter:http://www.maxtool.com/products/Wagan/2001.aspThis is the battery:http://www.beiterbatteries.com/12v_70ah.htm Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 8, 2006 Report Share Posted February 8, 2006 I clicked on "More Info" but nothing happened. That was the "more info" page. Not nearly enough info about the motor.I suspect it is a universal motor that runs the same on 115VAC as it does on 115VDC.The inverter also doesn't have any detailed spec's, but probably has a squarewave output which is +115VDC or -115VDC alternating. Full-wave rectify it and you have 115VDC for the motor and it won't make any difference. Quote Link to comment Share on other sites More sharing options...
Staigen Posted February 8, 2006 Report Share Posted February 8, 2006 HiAwful lot of connecting wires on that motor ???//Staigen Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 8, 2006 Report Share Posted February 8, 2006 HiAwful lot of connecting wires on that motor ???//StaigenHot, cold and internal ground for the rotor. Two wires for the field coil. One green wire for the frame. You could connect it wrong with both sets of wires and it will run in the correct direction.Two wrongs make it right. ;D Quote Link to comment Share on other sites More sharing options...
Staigen Posted February 8, 2006 Report Share Posted February 8, 2006 Hehe, ok, i did not thougt of that it was a reversible DC motor ??? :) :D ;D//Staigen Quote Link to comment Share on other sites More sharing options...
login
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.