Voltage changer

Thread Starter

MMoazam

Joined Jan 22, 2017
5
hey guys,
i wanted to ask a question.

i have a MAP sensor (sensor for cars) which out puts a 0 to 5 voltage. 0v means engine idle air intake in manifold and 5v means full throttle.
the question is how can i amplify this 0 to 5 voltages.

i want to use this 0 to 5 volt as a reference to control a pump PSI. the more voltage goes up the pump works with higher power.
the pump i use is 12 to 24 volts.

so which electronic parts i can use to amplify this signal?
or any other parts that would help me to use this 0 to 5 sensor out put voltage to control pump power.

thank you
 

crutschow

Joined Mar 14, 2008
25,664
To control the pump MAP sensor signal, I suggest you use a voltage-controlled PWM circuit to operate the motor.
That will allow power/speed control of the motor at much higher efficiency (with no heat sinks required) as compared to using linear amplifiers.
I can post a circuit for that, if interested.
 

MrSoftware

Joined Oct 29, 2013
1,936
You might be aware, but the MAP sensor won't directly give you the throttle position. The throttle position sensor (TPS) will tell you how far the throttle is open. The manifold absolute pressure sensor (MAP) tells the pressure in the manifold, which is not directly correlated to throttle position. For a normally aspirated motor, if you're at idle and you open the throttle, the MAP will read increased pressure. But as the RPM's come up and the engine begins to consume more air, the MAP will start reading slightly lower pressure. Not as low as idle, but lower than open throttle at low RPM. Have you also considered controlling your pump via the TPS? Also have you considered what might happen if the throttle is suddenly opened resulting in a sudden demand for more fuel, but it takes some time for the fuel pump to raise the pressure?

If you really want to drive your pump directly from the MAP signal (same method for the TPS), then I think you first need a high impedance buffer (such as an OpAmp) to sample the signal without altering it. Then you have multiple options. You can use the buffered signal to drive an analog voltage/current amplifier directly. You could use the buffered signal to a PWM generator using all analog circuitry. Or you can sample the buffered signal with a processor and use the processor to drive your PWM. There are probably other methods too. Do you have any constraints, such as power usage, heat, size, cost, tunability, power requirement of your pump, etc..?
 

Thread Starter

MMoazam

Joined Jan 22, 2017
5
To control the pump MAP sensor signal, I suggest you use a voltage-controlled PWM circuit to operate the motor.
That will allow power/speed control of the motor at much higher efficiency (with no heat sinks required) as compared to using linear amplifiers.
I can post a circuit for that, if interested.
thank you for the answer.
i appreciate if you post the circuit,
 

Thread Starter

MMoazam

Joined Jan 22, 2017
5
What are you going to do with the amplified signal?
the thing is i want to control a pump with changing its supply voltage.
the sensor out put voltage is 0 to 5 volt
but my pump is 12 to 24 volt.

so i need a circuit that change the out put voltage (12 to 24V) based on the in put signal (0 to 5V)

i want to control the pump based on the 0 to 5 volt that i get from map sensor.
 

dendad

Joined Feb 20, 2016
3,617
As @crutschow saya, it will be best to use PWM.
Run the motor off 24V and if the PWM varies between 50% and 100% that is 12 to 24V, and minimum heat loss.
An Arduino could read the 0-5V and generate the PWM as needed. Also, if more inputs of other signals are needed, that makes it easy to do.
 

Thread Starter

MMoazam

Joined Jan 22, 2017
5
As @crutschow saya, it will be best to use PWM.
Run the motor off 24V and if the PWM varies between 50% and 100% that is 12 to 24V, and minimum heat loss.
An Arduino could read the 0-5V and generate the PWM as needed. Also, if more inputs of other signals are needed, that makes it easy to do.
can you suggest any PWM board that i could use with Arduino for 24 volts?
 

dendad

Joined Feb 20, 2016
3,617
can you suggest any PWM board that i could use with Arduino for 24 volts?
One option, have a look at the MOSFET boards for 3D printers.
MOSFET.jpg
They are readily available on Ebay or similar.
This alone will not allow reversing the motor, but you do not need that for your application.
 
Top