Correct gauge wire

[rsbhunter]

Ordered some Monster 50' 14ga speaker wire....haven't recieved it yet...noticed it is copper plated aluminium wire. Should I return it and order pure copper? Using for 12v-12 ah battery.....should work for medium power single engine launches ? Thanks, rsbhunter

 

[Titan II]

yes

 

[rsbhunter]

yes

My fault for the confusion, yes it will work, or yes, return it? Thanks for the response. rsbhunter

 

[Titan II]

should work for medium power single engine launches ?

yes...it will work

 

[lr64]

It all depends. How much current will you be using, and how much voltage drop can you accept? Even pure aluminum wire would only have 10.6 ohms per 1,000 feet. So maybe, if yours is two conductor, the total resistance, there and back will be 1 ohm or less. The copper has to help a little bit, I should think, though I think it helps much more at high frequencies than with DC. 10 amps will lose you 1 volt, but how many amps do igniters really use? Keep in mind that a 12 volt battery usually puts out quite a bit more voltage than nominal. Obviously, it depends on the igniter, starting at something like 0.02 for something that Richard Nakka cooked up from a grain of wheat bulb, which would also fire on very low voltage. 10 amps seems really unlikely.

Anyway, my guess is that your wire would be enough to light almost anything you're likely to work with. Maybe someone else knows of igniters that use more than 10 amps. That's 120 watts, after all.

 

[rsbhunter]

Thanks, I appreciate the help...I'll be running 50', and of course, you are correct, the battery is showing like 12.83 volts...Thanks again....rsbhunter

 

[SolarYellow]

I've seen Monster speaker cable that looked huge but was actually just a copper (maybe even only copper-plated) braid around a polymer core. Lame, and for the stupids.

This is pure copper: https://www.homedepot.com/p/Woods-5...t-Duty-Extension-Cord-in-Orange-723/301132644

Works great for launching.

 

[tsmith1315]

I use outdoor extension cords as well.

 

[lr64]

I've seen Monster speaker cable that looked huge but was actually just a copper (maybe even only copper-plated) braid around a polymer core. Lame, and for the stupids.

This is pure copper: https://www.homedepot.com/p/Woods-5...t-Duty-Extension-Cord-in-Orange-723/301132644

Works great for launching.

Not necessarily lame if the main concern was for high frequency signals. But not so great for DC.

Solid aluminum is a fine conductor, and copper plated would avoid some of the corrosion problems with just aluminum, I think.

 

[rsbhunter]

Awesome, I have a couple extension cords going unused...if the speaker wire doesn't work, I'll use it for 12v led lights...Thanks to all of you...rsbhunter

 

[JimByrne]

I use 12 & 14 ga extension cords (12 ga for 100')
You should do fine with what you have
I feel bigger is always better

 

[Art Upton]

Just how high a frequency would speaker wire use ?
While RF [Radio Frequency] travels on the Skin or braid of wire, Audio is hardly RF.

This question is for IR64 and has no bearing on the launch controller.

 

[jsdemar]

Not necessarily lame if the main concern was for high frequency signals. But not so great for DC.

Solid aluminum is a fine conductor, and copper plated would avoid some of the corrosion problems with just aluminum, I think.

Copper plating reduces resistance based on the skin effect of current flow.

 

[lr64]

Just how high a frequency would speaker wire use ?
While RF [Radio Frequency] travels on the Skin or braid of wire, Audio is hardly RF.

This question is for IR64 and has no bearing on the launch controller.

I admit I didn't check just how high frequency it would have to be. My intuition suggests you may be right, but I don't actually know.

 

[jsdemar]

I admit I didn't check just how high frequency it would have to be. My intuition suggests you may be right, but I don't actually know.

High frequency impedance of a conductor pair is not the reason that low frequency wires have a copper plating. Even audio frequency current flow is dominantly concentrated on the outer layer of the conductor (skin effect).

 

[lr64]

I doubt if we're concerned with more than a Hertz or two in this thread.

 

[tsmith1315]

if the speaker wire doesn't work, I'll use it for 12v led lights

The speaker wire will be fine, too.

 

[rcktnut]

I've seen Monster speaker cable that looked huge but was actually just a copper (maybe even only copper-plated) braid around a polymer core. Lame, and for the stupids.

This is pure copper: https://www.homedepot.com/p/Woods-5...t-Duty-Extension-Cord-in-Orange-723/301132644

Works great for launching.

Exactly what I have and bought from Home Depot but a 100 ft. length. Never had a problem igniting any motor. The speaker wire will work also.

 

[jsdemar]

I doubt if we're concerned with more than a Hertz or two in this thread.

A firing circuit is an instantaneous step signal. Transmitting it depends on the high-frequency response of everything in the circuit, especially when driving a relay coil through a long cable. Mostly an inconsequential delay, except when back EMF could fry something in the the circuit.

I've been using orange power cords for launch systems for 30 years. Not only is there the resistance of the wire, there's resistance in the connectors (especially when they get dirty). It's common for a direct firing circuit (switch to cord to igniter) to not fire at over 50 feet. It's even worse when the battery gets a little low. The best solution is to put a 12V automotive relay at the pad. The relay coil only requires 100mA instead of 1A or more to fire the igniter. 500 ft is typically ok with this setup. But, you need another battery at the pad (or shared by a bank of pads).

When you get out to HPR distances, the cost of the wiring and the hassle of setup and tear down justified going wireless. No need to get the expensive Wilson system. There are cheaper homemade solutions.

 

[rsbhunter]

This all helps alot.. the power supply (12v battery) wire in to the control box has a connector that I can swap out easily with a 12 volt cigarette lighter plug, to use in a vehicle...I will test igniters though!!!! rsbhunter

 

[lr64]

A firing circuit is an instantaneous step signal. Transmitting it depends on the high-frequency response of everything in the circuit, especially when driving a relay coil through a long cable. Mostly an inconsequential delay, except when back EMF could fry something in the the circuit.

I've been using orange power cords for launch systems for 30 years. Not only is there the resistance of the wire, there's resistance in the connectors (especially when they get dirty). It's common for a direct firing circuit (switch to cord to igniter) to not fire at over 50 feet. It's even worse when the battery gets a little low. The best solution is to put a 12V automotive relay at the pad. The relay coil only requires 100mA instead of 1A or more to fire the igniter. 500 ft is typically ok with this setup. But, you need another battery at the pad (or shared by a bank of pads).

When you get out to HPR distances, the cost of the wiring and the hassle of setup and tear down justified going wireless. No need to get the expensive Wilson system. There are cheaper homemade solutions.

But you don't actually need an instantaneous step, do you? Isn't a fraction of a second enough for ramping up the power?

 

[Hobie1dog]

The speaker wire will be fine, you will get out of the hobby before it goes bad.

 

[Steve Shannon]

CCA offers no advantages over copper except weight and possibly price. I would never pay more for it for launch cables.

 

[rsbhunter]

It is less $ than pure copper...I did think it was pure copper, till I went back and read the description closer...but my mistake....it will either work, or not! But I believe it will be fine. rsbhunter

 

[Steve Shannon]

It is less $ than pure copper...I did think it was pure copper, till I went back and read the description closer...but my mistake....it will either work, or not! But I believe it will be fine. rsbhunter

It will work just fine. Aluminum is a very good conductor. Copper is better and silver is better still. The copper cladding helps for high frequency signals and prevents the formation of aluminum oxide, which is a terrible conductor. Copper oxide forms but is not a terrible conductor. Copper cladding also allows you to solder connectors to terminate the wire.

 

[rsbhunter]

Thanks, especially about the soldering info, hadn't thought about that aspect!! rsbhunter

 

[rsbhunter]

Got the controller done and tested, key on and push button. Shows 12.83 volt at alligator clips with 50' of the speaker wire...finishing up the pad tomorrow... maybe launch in a week or so...Thanks for all the help...rsbhunter

 

[lr64]

Did you put a load on it? You need some current to see what the voltage drop is.

 

[rsbhunter]

Used an 1157 bulb, on the bright terminal (stop light bright ) and dropped to 11.83 v. From what I can find, a 1157 pulls around 2 amps. I think I should be ok, the sla battery I am using is 12v/ 12 ah. rsbhunter