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Help. I can't get my potentiometer to work with my motor

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What battery does the toy car use?

The breadboard looks good, does it work?

That motor is overpriced, RadioShack is always expensive, you can normally get better deals from other places elsewhere.
 
Did you notice that RadioShack parts have no electrical nor electronic spec's? Just size and weight.
 
Radio Shack gives you instant gratification. I don't keep alot of parts around, and so it's often convenient for me to just stop and get what I need when I'm out running errands. Their parts are rather generic, so I can't use them in any specialized projects. Their inventory of parts used to be much better.

We used to have other parts houses around town. I guess the internet and the economy made it too hard for these business to survivie. That's too bad. Aside from carrying parts, they had a good inventor of used and surplus equipment.
 
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Like I said, the motor was salvaged from a toy car.. So I don't know. Is there some way to find out.. I'm sorry... I'm fairly new to circuits, but I'm learning a heck of a lot just from this one thread.
What voltage does the toy car run off? How many and what type of batteries does it use?
 
What battery does the toy car use?

The breadboard looks good, does it work?


It was intended for 2 AAs. So.. 3 volts?

The motor runs when hooked up to the breadboard, but nothing happens when I mess up with pot'. Most likely due to the motor, however. By the way, are the wires going to the right terminals on the pot'?

Like I said though, I will GLADLY pay for a motor from RadioShack at this point. With the number of wrong components I've purchased so far, I could have purchased 5 motors. I see videos of people setting this up in 3 minutes, when it's taking me multiple days. Maybe I'm making it more complicated than it is?

Point being. If you see a motor on that page that would be ideal for this set up, please point it out.
 
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It was intended for 2 AAs. So.. 3 volts?
The circuit needs a higher voltage than 3V, 4V minimum because of the MOSFET's threashold, even then you're pushing it and limiting it to low current loads.

What did you use for Tr1? It needs to be a logic level MOSFET, the IRL540 should do.
https://www.electro-tech-online.com/custompdfs/2009/08/91300.pdf

The voltage won't be a problem here, going by the picture, you've used a 9V battery anyway so it should work.

The motor runs when hooked up to the breadboard, but nothing happens when I mess up with pot'. Most likely due to the motor, however.
That should never happen.

Check the connections, from the picture, it looks like the there could be a short circuit somewhere, pay attention to Tr1; is it connected with the drain and source reversed?

Tr1 could be damaged.

By the way, are the wires going to the right terminals on the pot'?
That won't make any difference.

Like I said though, I will GLADLY pay for a motor from RadioShack at this point. With the number of wrong components I've purchased so far, I could have purchased 5 motors. I see videos of people setting this up in 3 minutes, when it's taking me multiple days. Maybe I'm making it more complicated than it is?

Point being. If you see a motor on that page that would be ideal for this set up, please point it out.

Apart from the fact that you've connected a 9V battery to a 3V motor which means both the battery and motor won't last very long.

I think you should use a 6V battery and a 6V motor.
 
Dumb question.. But is there any other combination? A 9v motor with a 9v battery? 6v come in lanterns... I need it portable
 
The motor should ideally be rated to the same voltage as the battery.

You can get 6V by connecting four AAs in series or use a lantern battery.

9V batteries really aren't powerful enough for what you're doing.

Does it need to be rechargeable?
 
What size is the 9V battery?

Unless you've changed it, it looks like this:
**broken link removed**

Is that right?

Power = Volts × Amps

A little 9V battery can't output enough current so its voltage will drop to 6V and won't last long.

There won't be much difference in speed between a 9V and 6V battery but four AA batteries connected in series will last much longer than a PP6 9V battery.

An IRF510 has a high on resistance and required quite a high gate voltage (5V to 10V depending on the current required) to pass a reasonable amount of current. You need a logic level MOSFET unless you're planning to power it from a 12v battery.

There is something wrong with the transistor or you haven't connected it up correctly otherwise the motor won't remain at the same speed regardless of the pot's setting. If the input voltage is too low, the motor won't work at full speed but the pot. should still work.
 
Most people would measure the resistance of the motor to calculate how much max current it needs.
Most people would use a mosfet that turns on properly with the low gate voltage in your circuit.
 
Yes! I got the pot' to change the speed of the motor with circuit #2! Although the same issue still occurs where turning the pot' all the way down leaves it still running and turning it up does nothing until the last 20%. What could be wrong? I followed the diagram exactly.

On a side note:

I actually found a battery at RadioShack that gives specifications.

This is a 1.5-3VDC motor

Current: 0.18-0.25A at no load
0.7A + or - 15% max efficiency

Speed: 8700 RPM at no load
5800 RPM max efficiency

Output: 0.31W

This actually might be same motor I salvaged from my toy car. It looks exactly the same...

I'm currently using the 6v motor with a 6v battery.

I also have a 9v motor. Which one should I use?

On a side side note: I don't even care what the max speed of the motor is. I don't need it to go fast at all. I only care that
1. The motor stops stops completely when the pot' is turned all the way down.
2. The pot' gives me a full even range, where the speed increases slowly throughout the entire turn, not just the last 20%.
 
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