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Help troubleshooting circuit I made

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Flash

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hello,
I am new here.
my names Brian, and its good to be here.
I can use some help.

I am into RC trucks, and in my truck I have a Smoke maker that is made for a train track set.
SO I had to custom install it.
The smoke maker is hooked directly to my 11.1v lipo battery to create the smoke. (using a internal 10Ω resistor.

The smoke unit also has a fan to blow the smoke out.
It has a small 9v DC motor installed in it.
So to make the smoke come out proportional I have hooked the fan to my RC truck motor as that gets 0 to 10v from the ESC.
0v truck is not moving all the way to 10v the truck is at full speed so smoke comes out full blast.

I have hooked up the fan motor directly to the RC truck motor and it works proportional, so i know it works like that.
but when the truck is stopped my Smoker fan does not spin (because the RC truck motor has 0v getting to it)
This is bad for the internal 10Ω heating element.

so I decided I wanted to make the fan idle at about 2.5v all the time so a steady stream of smoke comes out my tail pipes.
(this will do 2 things make the truck look more real when sitting still, also it will keep the air moving across the heating element to keep it cooler.
that is where I am having my problem.

I decided to use a LM317 voltage regulator and have found a resistor calculator online to help me with that.
Also I am using full wave bridge rectifiers so that the fan does not spin in reverse when I put my truck in reverse. ( I did notice that those do draw a little power)

I am able to get the smoker fan to idle at a good speed now using LM317, but when I go to use my remote to move forward just a little bit my smoker fan shoots up really high in RPM's. it did not do this before when I had it hooked directly to the DC truck motor.
so I know it is a problem with my circuit.

can you look at my schematic and tell me why my smoker fan is going from my 2.5v steady idle then jumping up to a high voltage as soon as I go forward just a tiny bit at slow speed.
the smoker fan hits full blast or sounds like it.

I have included this video and my pictures so you can see for yourself my problem. :)
thanks again

Video

**broken link removed**

here's my truck

**broken link removed**

here is my smoker mounted and wired in the box

**broken link removed**

here is how it is wired.

**broken link removed**


please if you could take the time and read throught this and help me solve my issue of as to why when I have my circiut ran this way I have no more proportional smoke control of my smokers fan.?

thanks again for any help or tips you can give me.
I really appretiate it

Brian
 
With the LM317 providing a steady 2.5v, your providing 2 paths for current to get to the fan when the motor gets power. I'd imagine thats why it speeds up so much sooner. Its only a 9v motor and your already close to a 1/3 of its rated voltage when you turn on the motor.
 
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I think I am onto something.

When i disconnect my power connector from the lithium battery to the top circuit
the smoker fan works nice and slow again.

it just has something to do with adding the voltage regulator into the circuit that is causing problems.

do you see a ground problem?

can you take another look?

thanks
 
is there anyway I can draw this in Linear Technologys LTspice/SwitcherCAD III and then run some tests on it?

I have downloaded the software but I caanot find the components I need?
Like LM317T and GBL005

if this is possible could you tell me how to?
if not possible can you point me in the right direction so that I can find the proper Circuit testing software.

thanks

**broken link removed**
 
Question: Is the lithium battery connected to anything else? Specifically, is it connected to the receiver circuit, which then supplies the 0-10V to the RC truck motor? That could be your problem.
 
thank you you just helped solve my issue.

Yes the lithium battery is the same one that was driving my ESC and receiver.
so I diconected the top from the lipo and hooked it to my bench P.S. and tried it that way and the fan idles nice and the fan also has proportional control, also the heater works from the 12v from my bench P.S.

So I was considering using two 11.1v lipo battery's
now I think I will, with the one controlling my smoker and LED's having its own cutoff.

unless there is a fix I can wire up to my current circuit to correct what ever is going on because i am using the same battery to control the ESC.

?

thanks again either way!!!
glad I joined this site!!!:D
 
unless there is a fix I can wire up to my current circuit to correct what ever is going on because i am using the same battery to control the ESC.
It is hard to say. It depends on how the truck motor is controlled. You need to measure the voltage between the Lithium battery's (-) terminal and each of the truck motor terminals with it operating in forward, reverse and stop. If the voltage between the Lithium battery's (-) terminal and truck motor terminals is zero when 0 throttle is given (stopped), and only one terminal at a time varies in voltage with forward and reverse throttle (the other stays near zero), then there is a simple solution to this:
 

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