how to drive micropump using 0-5V and 5 mA input signal

[sapit]

i am using a micropump which operates at 3-12 Vdc (Max 0.5 Amps). I need to control the speed of this pump by varying the voltage between 3-12V.
my input voltage is from NI daq 6008 which ranges from 0-5V and output current drive is 5mA. I had tried to use a lm741 op amp with gain equals to 3 but it doesn't drive the pump. pls help me.
this is the link of the micropump that i am using (**broken link removed**).

 

[Electro nS]

very easy , assuming the pump is rotating in one direction .

use your output of Dataacquison system to control a 555 timer which well generate PWM to control an npn or darlington transistor in low side configuration.

i am attaching a similar circuit the motor is your pump the variable resistor R1 is your input signal from DAQ. and VCC is 12v constant. please replace the mosfet transistor by darlington or npn transistor like tip 140 or similar for your convience and ease of use .
**broken link removed**

hope that helps

 

[crutschow]

The 555 PWM circuit that Electro ns referenced is controlled by a floating mechanical pot and is not readily controlled by a voltage input as the OP wanted.

Here is an IC that should allow you to control the motor speed by the control voltage using PWM. You will need to add a Logic-Level type N-MOSFET driver on the output to provide the 0.5A the motor requires.

The maximum output of a 741 op amp is about 25mA so it obviously can't drive the pump directly. To use a standard op amp you would need to add an output buffer. I can post a circuit if that's what you would prefer to do but that's less efficient than the PWM circuit.

 

[sapit]

The 555 PWM circuit that Electro ns referenced is controlled by a floating mechanical pot and is not readily controlled by a voltage input as the OP wanted.

Here is an IC that should allow you to control the motor speed by the control voltage using PWM. You will need to add a Logic-Level type N-MOSFET driver on the output to provide the 0.5A the motor requires.

The maximum output of a 741 op amp is about 25mA so it obviously can't drive the pump directly. To use a standard op amp you would need to add an output buffer. I can post a circuit if that's what you would prefer to do but that's less efficient than the PWM circuit.

can you please post the circuit? thank you

 

[sapit]

hi crutschow, can you show me how control voltage speed using pwm?

 

[Electro nS]

check this link it will help you understand the concept ..

https://www.youtube.com/watch?v=YmPziPfaByw
https://lizarum.com/assignments/physical_computing/2008/pwm.html

your welcome !!