Greek Phil 5 Posted August 1, 2011 Report Share Posted August 1, 2011 I know this is an frequently reoccurring subject but its one that I still cant solve . Being a complete starter when it comes to electronics. I want to build a in line dimmer set up so that I can swap it between the various lamps I use. OK so here's the questions. What the difference between a variable speed resistor and a variable potentiometer? As I have seen posts recommending both. What ratings would I need to run 100 watt lamps? If I go to some where like Maplins can i buy the necessary mounting boxes, connectors, turn knobs, cabling and heat shrink that I would need? I prefer to use the correct rated AmpH DIM jack plugs and sockets rather than the crappy cigar lighter power supply options. But have in the past hooked up straight off the battery. As I like the feed to be constant rather than thru the vehicle ignition switch.Always ensuring there's at least 1 in line fuse. Which method is best if using a dimmer? Can anyone post up a guide to wiring said system. If you can make it understood by a 6 year old so much the better. Thanks. Quote Link to post
Greek Phil 5 Posted August 21, 2011 Author Report Share Posted August 21, 2011 What, no one can provide an answer.....?????? Quote Link to post
dymented 2,220 Posted August 21, 2011 Report Share Posted August 21, 2011 Variable resistor is used to carry the current while providing voltage drop. i.e. on a dimmer switch, the more resistance it puts out, the darker the lights are. Potentiometer is basically a Variable resistor, but it works as an input sensor which provides a signal. it does not carry the current goes to the load component. i.e. the foot pedal on a Tig welder, it tells the welding power source how much amperage it needs to put out, but, welding current doesn't flow through the foot pedal itself. Quote Link to post
Greek Phil 5 Posted August 21, 2011 Author Report Share Posted August 21, 2011 Brilliant... no pun intended! Is that why variable resistors hum? What rating would I need to run a 100 watt lamps thru a v resistor? thanks GP Quote Link to post
pipcock 21 Posted August 25, 2011 Report Share Posted August 25, 2011 (edited) type in google, ohms law calculator . 100W /12V = 8.3333A so it would be 10A fuse http://www.the12volt.com/ohm/ohmslawcalculators.asp Edited August 25, 2011 by pipcock Quote Link to post
pipcock 21 Posted September 2, 2011 Report Share Posted September 2, 2011 What, no one can provide an answer.....?????? i've provided you with one but can you understand it Quote Link to post
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