The cheap thing is to get one of the 12VDC-120VAC converters of the 100W variety. These will run on anything of 11V or so up to 15V without problems. Usual cost at a discount place is abut $40 or so. FWIW, I've taken several and made drive correctors out of them and have a webpage on the subject. Bob May http://nav.to/bobmay bobmay@nethere.com NEW! http://bobmay.astronomy.net