Anyone ever heard of resistor wire?

[Incubus]

A don't know if it's a type of wire or a purpose for a wire. It's in the instructions of a transistorized ignition I got for one of my cycles. The connection between the points and the transistorized unit is supposed to be made with a "resistor wire," and the wire is supposed to be yellow. It did not come with the kit.

Any ideas, anyone? None of the auto parts stores, home improvements stores, electronic stores or my local cycle dealer knows what this means.

Thanks,

Patrick

[wingnut]

1 ohm per foot

I'm a little out of my league here as this is electrical but. I'm thinking they are talking about the type of solid wire that is used say in a variable riostat (sp). It has a known ohm rating per foot or inch. If I remember right the ohm rating is determined by the size of the wire. I had to get some to rebuild the outdrive position transmitter on my boat. A aircraft instrument overhaul place or good electrical supply house should have it

[John]

Patrick

They were used in the wiring harness of many old Fords. We use them a lot at work. It replaced the ballast resistor in the ignition system. You may be able to buy that section of harness from a Ford dealer, or if they can't help you, I may be able to cop one for you. Let me know if you can't get one, and I'll see what I can do.

[fredintoon]

An electric clothes dryer element

( for instance ) is coiled up from yards of the stuff.
Thing is, I'd suppose you'd have to know how much resistance your iggy system needs. Did the instructions quote an Ohms number?
Fred Hill, S'toon.

[HobbyMan]

Why, all wires have resistance never mind. post has been edited by me because I missed John's post.

[Incubus]

The only instructions that came with the ignition was the wiring diagram on the box. I can't do much with it today - it's way too friggin cold to actually do anything on my bikes. It is, I swear, the coldest day in the history of Central Texas, and that includes all those years before there were people here. Anyway, I'm starting to think there was supposed to be a wiring harness with the ignition or available for it. The diagram, I figure, was only offering the right color code for the harness. So I am probably going to have to fabricate some kind of resistor to put in line there.

There are no markings on the unit to indicate ohmage and a internet search for the manufacturer and distributor turned up nothing. They probably disappeared 20 or 30 years ago.

Can anyone tell me how to figure out what resistance I would want to use to protect the points sets?

Thanks,

Patrick

[tommystinson]

Resistor wire is often nichrome wire, like in a toaster. It was used in the cheaper vacuum tube radios years ago to drop line voltage. It may be used in this application to reduce RFI from the points switching a load, or possibly just to reduce voltage. Any more info on the ignition box? It sounds like transistor "assisted" ignition to me, the points are sheltered from the inductors, so to speak.

[Incubus]

Here, is the wiring diagram on the box the ignition came in. There were no other instructions included. Now, I'm not an electrical genius - just ask the guy I hire to change light bulbs for me. That guy's a wizard - they work EVERY TIME. Anyway, this seems to indicate that the resistor wire is designed only to protect the points by reducing the voltage to them. I was thinking of just wiring a couple of ballast resistors in line on the points lines and see if that works.

I wish I knew about that clothes dryer thing, Fred. I just hauled one of those off to the recycling center a few days ago....

[TopCatGr58]

Hey Patrick,

Yeah, I looked at it and figured that before I read your comments. I don't know if you need to use a ballast resistor vs. just a resistor in line. Might not get as hot. The power to the points is going to be intermittent since the points are opening and closing. Also, less HEAT in wires the safer IMHO!

But hey, like you I'm no electical genius either. I know resistors get warm also, just don't know if one designed for electronics could handle the required amps and volts? Just like the 78-80 coils, they only use a 1.5 ohm resistor to drop the voltage from 12 to ~9, perhaps that's about all you'll need as well.

Main thing is you can monitor the points for how fast they get burned on the contact surface. I remember having to redress the ones on my 69 firebird every 6 months or so, until I got the Blue Streak brand!
T.C.

[rockjok]

I use resistance wire (appliance hookup wire) to make heated clothing. This would be a bit different from what I think you're looking for.

Anyway, here's a possible link to a site that may be able to help you:

http://www.resistancewire.com/mainpa...ge=alloytables

Rob

[Pat Kelly]

Last time I bought resistor wire was at an auto parts store. It's been a few decades ago, back when ignitions were points-type. It was used instead of a ballast resistor on some Dodges. I probably have some around somewhere as I never throw anything out.

[randy]

Patrick,

If it's truly a transistor ignition, can't see the need for the resistor wire.??

What is the Mfg's name and what model # is the unit?

[Incubus]

Randy,

The ignition is an Ultra Transistor IG System made by Ultra Electronic Inst. Co. Ltd. of Tokyo and distributed by Akashi Engineering Inc. of Gardena, Calif. The model number is UTI-750. I've searched the internet for information from either company and on the model number in hopes that ancient technical support was still available, but I can find no references to either. I suspect the company ceased to exist or changed its name sometime way back in the day.

[DiverRay]

As this is going on the 750 Honda, ( my guess) I would just use a pair of ballast resistors. The resistor wire is used to prolong the life of the points, so the actual value isn't too critical. The 1.5 Ohms will cut the voltage to the points, and keep the current down going through the "black box".
The points are used to "fire" the coils by making and then breaking the circuit. When the circuit breaks, the field around the steel core collapses, and creates the spark. The box is using the points to fire a stronger ( higher voltage) signal to the coil. This with the transistors, give a much more precise time of spark, and in some models, a longer or double spark. The better spark will insure all the fuel has ignited, and you get all the HP out of the engine.

[LoserShoes]

So how about searching on "Transistorized Ignition", and seeing if you can find a similiar system to get some idea of the value of the resistors.

Steve