The Stovebolt Site Forums The Shop Area The Electrical Bay Voltage Reducer

I bought a supposedly 12 volt to 6 volt reducer from the parts store. I put 12 volts on post. Is the other post suppose to be 6 volts. It's one of those white ceramic types. Thanks!

hillbillytim,

Welcome to the bolt!!!

Ceramic voltage drops that are commonly sold throughout auto parts stores typically have a 40% error rate.That may not have much of an effect on a heater blower motor that runs on 10 amps of current,but it is a heck of a lot to a fuel gauge that runs on just a quarter of an amp.The ceramic voltage drops also develop a lot of heat which is why the are encased in ceramic. Use caution where it is mounted.

You may find other types of reducers at auto stores or radio shacks. While some may work ok they are not designed accurate enough for dash gauges and do not have the circuit protection of a RUNTZ reducer. If you are reducing voltage for gauges, use a Runtz EL311, they are around 15.00 DO not use this type for the amp gauge as that gauge is not voltage senative.

Hope this helps,
Dave

Dave

hillbillytim,

Welcome to the Stovebolt. It sounds like you purchased a ballast resistor. Although this could be classified as a voltage reducer because that's what it does, it wouldn't be something you would want to stick in front of a sensitive electrical component.

A ballast resistor is a white ceramic device with a wrapped piece of resistance wire encased in it. Its use it to reduce operating voltage to the coil and ignition system on rig built in the '60's and '70's.

It isn't a regulated voltage reducer, and I believe you will get more than 6 volts out the back with 12 volts supplied...more like 8 or 9 volts.

They do make a round ceramic voltage reducer that would drop the voltage to things like a heater motor, and they might be calibrated to achieve a 6 volt output...this is probably what you have. They might have been produced with a name like Volt-a-Drop or something.

This resistor isn't directional. Hook your 12 volts to either end, and the other end will be the reduced voltage.

What is the intended use for your reducer?

Stuart

Welcome to the 'bolt hillbillytim;
A voltage drop resistor doesn't work until it's actually in the circuit with current going thru it. If you just hook 12 volts to one end and look at the other end (not connected to anything) it will still read 12 volts. To see if it's the right value for the circuit it's in: connect it in series with whatever load it is going to power, (turn the load "on", i.e. heater motor, radio, etc.) then read the voltage at the output of the resistor to ground. Should be somewhere in the 6 volt range.

I'm hooking it to a 6 volt coil. Just using a 12 volt battery to start and move the truck around the yard. All other electrial items are unhooked. Thanks Guys!

HEY GUYS! I'm doing a 6 to 12 volt conversion at this moment and wanted to use my origianl 6 volt coil with an inline ballast resistor from the ignition swith to the coil, just like hillbillytim is doing. Will that work as a permanent conversion or will the coil need be 12 volts? ALL of the online internet sites, including Patrick's say you must use a 12 volt coil when converting and also a ballast resistor. DON'T MAKE NO SENSE! Also, I have a 6 volt electronic ignition module instead of points which I hate to scrap. Can I retain that as long as I use the resistor upstream from it? (The electronic ign. module positive is wired to the coil positive. So I'll be pulling amps to both the coil and module directly from the ceramic ballast resistor.)

I changed over a friends 53 1/2 ton a few years back. I used the ceramic reducer like i have hooked up now to the 6 volt coil.He never had any problems until he hit a deer!

Hit a DEER!? That must've cost him dearly! My hillbilly aunt Bonnie many years ago up in Mount Shasta area Northern California took out her pontiac that way. Total loss, for the deer too.

Thanks for the tip. I got all kinds of double talk from the "experts" at the Truck and Car Shop in Orange County California where I get some of my parts. I'll hook it all up like you said and give it a shot. Worst can happen I need scrap the electronic module and the coil for a 12V version and points which prettymuch figured I'd have to do anyway!