# Controlling speed of motor using a switch and potentiometer

I am working on a project in which I have to create a circuit where the speed of the motor should not increase more than 40 km/hr until the switch is pressed. So how can I do it??

Speed of the motor will be increased using a potentiometer.

Dark_wiz:
I am working on a project in which I have to create a circuit where the speed of the motor should not increase more than 40 km/hr until the switch is pressed. So how can I do it??

Speed of the motor will be increased using a potentiometer.

Motor speed is always RPM, revolution per minute. Are you supposed to use an Arduino in your project? Are you supposed to measure the RPM of the motor or is the motor operating something that may move 40 km/hr?

Paul

How are you measuring the speed of the motor?

I think that a more thorough description of the project is in order.

If it is that urgent, you could save some time by reading and following the advice in the forum guidelines posts.

"I am working on a project in which I have to create a circuit where the speed of the motor should not increase more than 40 km/hr until the switch is pressed. So how can I do it??"

I'd probably check the switch state in an "if/else" statement.

"I am working on a project in which I have to create a circuit where the speed of the motor should not increase more than 40 km/hr until the switch is pressed. So how can I do it??"

I'd probably check the switch state in an "if/else" statement.

Create a boolean variable for switich_state.

Without knowing what kind of switch it is how would we know how to 'check' it ?
If you rely on software instead of h/w to check the state it could easily be wrong if the operator had
not initialized it. What does the switch do ? If it's just a logic input then there's no problem checking it.

Meaning what ? (you are late getting started on your homework assignment ?)

Hi,
Welcome to the forum.

Please read the post at the start of any forum , entitled “How to use this Forum”.
OR
http://forum.arduino.cc/index.php/topic,148850.0.html.
Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.

Do you have any code?

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Can you tell us your electronics, programming, arduino, hardware experience?

Thanks… Tom…

I am measuring the speed of the motor by building an analog speedometer. I am using normal press switch.

The motor is rotating a wheel . I have just started with the idea. I don't know how to begin with the circuit.
What all components are required?

Dark_wiz:
I am measuring the speed of the motor by building an analog speedometer. I am using normal press switch.

Are you building an analog tachometer????? Please confirm it's either a tachometer or a speedometer. A speedometer will measure the speed of the surface of a shaft as it passes a certain place.

A tachometer measures the rotation of shaft in revolutions per minute. I have two analog tachometers. One uses a rubber tip pressed to the center of a rotating shaft. The tip and it's shaft rotate a magnet inside the indicator which moves a spring loaded needle pointing to the RPM of the shaft. The other analog tachometer turns a very fine pitch screw which drives an analog turn counter. You press the tip of the counter to a turning shaft for a specific time and then read the turn count that has occurred during that time period.

Are you building either type of analog indicator and why is an Arduino involved?

Paul

"The motor is rotating a wheel . I have just started with the idea. I don't know how to begin with the circuit.
What all components are required?"

Use the forum Google search function in the upper right of this page to search for the key words of your project. You will probably find many similar previous project discussions and code to get you started.

Paul_KD7HB:
Are you building either type of analog indicator and why is an Arduino involved?

I didn't understand it. An Arduino is required for the working of potentiometer and controlling the motor.

Dark_wiz:
I didn't understand it. An Arduino is involved for the working of potentiometer and controlling the motor.

And I quote: "I am measuring the speed of the motor by building an analog speedometer. I am using normal press switch.".

So how are you building the analog speedometer?

Paul

For analog speedometer, I am referring this site:

Dark_wiz:
For analog speedometer, I am referring this site:
Arduino Based Analog Speedometer Using IR Sensor

I guess you want to play word games rather than get help with your project. The ONLY analog part is using scissors to cut the paper to make the dial.

Get you help elsewhere.

"For analog speedometer, I am referring this site:"

I think I would use a small servo instead of a stepper motor. Get the IR module and work on getting a reading from that and convert to a numerical value. Once that is done you can add the other parts.

zoomkat:
"For analog speedometer, I am referring this site:"

I think I would use a small servo instead of a stepper motor. Get the IR module and work on getting a reading from that and convert to a numerical value. Once that is done you can add the other parts.

I agree, it would be the simplest.
Here is a simple example of an analog input to servo output.
Use the servo arm as the meter needle.

Tom...