customers car, stock '51 ford wagon with a 12v charging system (12 pos ground alt). has a 12 with a 6v tap battery, the only thing on the car now that is 12v is the charging system and starting system (had a/c on it). i was wondering if there is any voltage reducers that could handle the amps of the lighting and ignition systems. i would like to go away from the battery thats in there and go to a regular 12v one.
It would be one chunky bit of kit with a m***ive heatsink if it exists and probably more expensive than the 12V parts for the conversion. Also how would you charge the 12V battery with a 6V dynamo?
Done with switchmode I can't see it being any larger than 1-2 cubic inches, with just a couple of watts being dissipated. Do you need it to regulate down to 6V, or just divide the 12V in half? You can probably start off with an off the shelf electric RC car speed controller (fixed at 50%) with a little bit of (optional) filtering. Cheers, Mark
Change the bulbs to 12 volt bulbs. If the switches (light and high beam) are in reasonable condition they will take 12 volts easily. As for ignition, change the coil, the condenser in the dizzy, solonoid all to 12 volt and you are all set. You have to remember, it takes a lot more amps to run a 6 volt system than a 12 volt system. That's why you do not have to change wires when making a 6 to 12 volt change. If your in the business, you should already know this.
customer doesn't want to do a full 12v conversion (the gauges will also have to have reducers along with the radio, clock and heater). the car is stuck half way hence the 12/6 battery. i was just wondering about a reducer so i could use a regular 12v battery. i know the larger reducers are for around 2-5 amps (ron francis makes a 15amp one) and they make higher amp ones for 24v to 12v. so it's either get another battery (12/6) or convert back to 6v.
For the instrumnets you'll have to get some ceramic coated resistors. Ohmite makes the best if they are still available from Newark Electronics. You will have to drop the voltage from 12 volt to 6 volt. I haven't used OHMs law in a few years but it will probably be around 1 Ohm with a high enough watt rating to take full time use. Talk to someone who is familiar with electronics and thay can halp figure Ohm & Watt ratings. The resistor/s will have to be mounted on an insulated board that is not near any flamable objects due to heat disipation. You also might check some of the early 12volt cars like Chevys or Fords of the mid to late 50s because they kept using dropping resistors for guages/instruments for several years after they went to 12 volt. These devices are already set up to work as I described previously if you can find one in usable condition. Your fuel quan***y, water temp, and oil pressure guages would be the most critical. An amp meter dousn't care what the voltage is.
i did find one that is 50amps but after more research it sounds unlikely that the gauges will work properly. i'll talk to them again but i think they'll just go with the 12/6 battery. i've done 12v conversions in the past, my '47 has been converted (not by me), i'm cleaning it up and making everything work with 12v that wasn't hooked up yet, but on their car it really up to them on what they want to do. thanks again guys...........
PM Mart here on the HAMB - he sells a very nifty 12-6V convertor for gauges. Lights & bulbs are easy. You'll need those "high amp" converters for the heater & radio... If the customer doesn't want to do a proper 12V conversion I think you're stuck with a 12V battery w/6V tap... FWIW, my gauges work perfectly after the 12V conversion (they are stock 6V gauges using one of Mart's voltage regulators).
i just finished my '47 gauges with the reducers and they seem to be really accurate. i also found a 12v blower motor that will work (i didn't want the heat under the dash from a ceramic reducer).
If it were mine, I'd just put it back to a full 6V system OR finish the conversion to 12V the right way. As you know a '51 Ford runs just fine with its original 6V system.
Speedway motors has "RUNTZ" resistors for guages and bulbs and radios.....also small individual resistors can be got at any decent electronic supplier....the rating needed is 2.0 OHM for 12 to 6 volt conversion as I recall.... for fans and motors an ordinary ignition ballast resistor will do the job.....BUT do not use for the stuff I mentioned above....ign resistors work like a 'toaster element' and have to heat up....and there is an initial high voltage surge that will fry the sensitive stuff (bulbs, gauges, radios, other electronics). electric motors are far more forgiving because the wound fields/armatures already offer resistance by virtue of the windings...... hope this helps technically speaking.....
The Jalopy Journal
