Don't worry, you can buy instead of make. There are tons of PWM controllers for sale on e-bay. Think of it as getting a dimmer. Just be sure to get one rated well above whatever specs you need. Those e-bay sellers might be a little generous in their claims.

Do you have someone's design you are following? I'm a little skeptical this will work. A metal wheel at 30mph in sub-freezing temperatures will dissipate a butt-load of heat. I really don't think you can get enough heat into it to make any difference. Add to that the fact that you need a lot of heat to thaw ice, and I just can't see it. If we're talking about a stationery wheel, maybe.

Hmm the attachment would be on the wheel well or undercarriage of the car not the wheel itself. I have heat loss calculations so that isnt my issue. I need to know about how to wire/controll the nichrome. Thats why I am here isnt it (;

 

OK, fair enough. I remain skeptical but don't let that stop you.

 

Hmm the attachment would be on the wheel well or undercarriage of the car not the wheel itself. I have heat loss calculations so that isnt my issue. I need to know about how to wire/controll the nichrome. Thats why I am here isnt it (;

Oops.. Forgot the link.
http://www.ebay.com/itm/20A-Univers...734141?hash=item3d089121bd:g:zG4AAOSwpRRWpcs4

 

OK, fair enough. I remain skeptical but don't let that stop you.

I think someone earlier said that you only need to melt the layer of ice/snow attached to the undercarriage.
I don't live in a geographical zone where such climate is a common occurrence. But I do remember that ice and snow can act as insulators under some conditions.

My point is, maybe we're overestimating the necessary power to accomplish what the op wants?

 

Why do you want to use electricity when you have so much heat from your engine right next to those wheel wells. Just cut out a piece of fender and add a blower motor from under the hood to the unsightly snow and ice built up on the wheel well.

 

Why do you want to use electricity when you have so much heat from your engine right next to those wheel wells. Just cut out a piece of fender and add a blower motor from under the hood to the unsightly snow and ice built up on the wheel well.

Or perhaps a coil of copper tubing derived from the exhaust?

 

Why do you want to use electricity when you have so much heat from your engine right next to those wheel wells. Just cut out a piece of fender and add a blower motor from under the hood to the unsightly snow and ice built up on the wheel well.

Not to sound rude but i came to the forum to discuss the electronic components of my idea not the implemetation of the solution. I want this to be universal to my cars main reason its electrical. Anyways would love some better understanding on how i could control the temp of the wire

 

Nichrome controls itself as far as current and power. Just pick the right diameter and length to use up the wattage you want and connect it with a relay.
I do have some doubts about putting a rubber case around it.

I just ran the math on Calrods stolen out of kitchen stoves or toaster ovens. No joy.
I guess we're going to have to look up the nichrome tables and see what gives.

 

Not to sound rude but i came to the forum to discuss the electronic components of my idea not the implemetation of the solution. I want this to be universal to my cars main reason its electrical. Anyways would love some better understanding on how i could control the temp of the wire

Well, all of my cars have
- all my cars have wheel wells next to the motor
- all my fans use electricity

The fan-in-the-wheel well would work for me.

Also, your solution has a few challenges. Engine must be running because a battery cannot support it.
350F is a temperature, it is not a unit of heat. You will need pretty massive heaters to actually melt the snow/ice. So big that you will likely melt the plastic fender liners common to most modern cars. If those are not present on your car, you will be damaging the paint as the heat will easily pass through to the nice looking side of the fender. Lastly, the black sidewalls of your tires will get very warm and likely start checking/dry rotting at those temperatures.

If you have answers to those issues, good luck.

 

plastic fender liners

My recently purchased Ford Explorer has what looks like tar paper wheel well liners.
I guess it's a form of plastic.
I don't think it would survive over 200F.

 

or maybe an auto-bong?

I thought that was a German Motorway?
Max.

 

My recently purchased Ford Explorer has what looks like tar paper wheel well liners.
I guess it's a form of plastic.
I don't think it would survive over 200F.

It may have been mentioned earlier but, to melt any ice in the windy wheel well of a moving car, quite a bit of heat will be needed. That potential heat will be well insulated inside of a rubber hose? What kind of design idea is this? And the most interesting part is that his biggest concern is controlling the temperature of the wire. How many BTUs does he think will pass through each foot of this rubber hose? His whole wheel well will be filled with dozens of yards of rubber hose - problem solved. There will be no room for snow and ice build up with all that rubber hose in there.

 

I thought that was a German Motorway?
Max.

wow... I hadn't thought of the possibilities of a no-speed-limit auto-bong!

I do have some doubts about putting a rubber case around it.

a red silicone rubber might be able to take the heat, if the nichrome's temperature is carefully monitored and controlled

 

It may have been mentioned earlier but, to melt any ice in the windy wheel well of a moving car, quite a bit of heat will be needed. That potential heat will be well insulated inside of a rubber hose? What kind of design idea is this? And the most interesting part is that his biggest concern is controlling the temperature of the wire. How many BTUs does he think will pass through each foot of this rubber hose? His whole wheel well will be filled with dozens of yards of rubber hose - problem solved. There will be no room for snow and ice build up with all that rubber hose in there.

Maybe if we were to help with a basic electronic (more like electric) design the OP will begin to understand the practicality of his idea?

 

wow... I hadn't thought of the possibilities of a no-speed-limit auto-bong!


a red silicone rubber might be able to take the heat, if the nichrome's temperature is carefully monitored and controlled

This is exactly what i have. My plan is to have a zig zag pattern of the nichrome wire sandwiched between two sheets of it.

As for people saying it wont be hot enough... 110 F is a fine temp im not tryingto collect running water just prevent it from building up. Rubber already has a low coefficient of friction plus if it is mildly warm snow should slip right off.

 

Not to sound rude but i came to the forum to discuss the electronic components of my idea not the implemetation of the solution. I want this to be universal to my cars main reason its electrical. Anyways would love some better understanding on how i could control the temp of the wire

Don't be offended.

It's natural to want to understand the entire context of a problem, often, a reasonable solution is not visible without doing so.
Once "The Problem" has been fully disclosed, all attention tends to focus on the big picture, which leads to bigger questions...

All of this is done in the spirit of helping you with the "Big Picture" - achieving your main goal.

 

Don't be offended.

It's natural to want to understand the entire context of a problem, often, a reasonable solution is not visible without doing so.
Once "The Problem" has been fully disclosed, all attention tends to focus on the big picture, which leads to bigger questions...

All of this is done in the spirit of helping you with the "Big Picture" - achieving your main goal.

I understand what everyone is saying but in the end im going to do the project the way I want to. I came to a forum about circuitry to learn about circuitry. I could have gone to a DIY forum and gotten input on the design.

All in all lets just pretend my problem is that I want to heat and controll the temperature of a nichrome wire with the power coming from a car battery. Thats my issue and thats what i want help with

 

And we are trying to help you understand that it's not going to work using that approach.

The amount of electrical power required is substantial, a car's electrical system cannot support it.

If it could, your car would be ice-free already, standard equipment.

 

I understand what everyone is saying but in the end im going to do the project the way I want to. I came to a forum about circuitry to learn about circuitry. I could have gone to a DIY forum and gotten input on the design.

All in all lets just pretend my problem is that I want to heat and controll the temperature of a nichrome wire with the power coming from a car battery. Thats my issue and thats what i want help with

Alright... I think I can understand (and relate to) what you're saying. You want to accomplish something (even if it's not the best way to do it) and in the process learn some electronics and control techniques along the way. Or maybe it's the other way around... you want to learn electronics, by building something useful to you... even if it's not the most practical way to do it.... Fair enough.

Question: what's your background in electricity and/or electronics? Do you have an engineering degree? The reason I ask is because I'd like to know at what level we should get started.

 

And we are trying to help you understand that it's not going to work using that approach.

The amount of electrical power required is substantial, a car's electrical system cannot support it.

If it could, your car would be ice-free already, standard equipment.

In my understanding the cars heated seats use a similar circuit and maybe the rear defroster. If my car has a 180 amp alternator and 100 amps are used with all electrical on then i have some room to wiggle. If someone could give some rough estimates of how much energy this would draw it would really help me understand. Figure i need 50 inches of wire on each front wheel well 100 total and the avg car battery is 14v when in use what are the implications. I came here expecting some technical answers...