Hey everyone, I am a mechanical engineer and very new to Arduino.
I have a proportional valve where the position is controlled by varying voltage from 0 to 20VDC and has a max current of 0.2A. Alternatively it can take a constant voltage pwm of >=2kHz. Is it possible to control this valve with an Arduino Uno, possibly with a small off the shelf boost converter or similar? I am hoping to not have to do any serious electronics design or manufacture.
I was able to get the Uno to output a high frequency pwm, so now I am just trying to figure out how to boost the voltage/current available. Thanks in advance!
I don't see any use for a boost converter. The Arduino is not a power supply, so you will need a separate one for the valve.
A commonly used circuit for PWM proportional valve control is a constant current driver. Such circuits can be Arduino compatible and are easy to make. Discussed in this forum thread.
You don't need a constant current driver with PWM (analogWrite() on the Arduino). For example, 50% PWM (a PWM value of 127) is an average of half the supply voltage (and half the average current).
A **MOSFET driver **works fine with PWM and if you can get a 20V power supply, you won't need a boost converter.
If you do need to boost from 5V to 20V, you "loose" current when you boost voltage. Power (Wattage) is calculated as Voltage x Current so with 5V in and 20V out, you'd need 0.8 Amps from the 5V source if the converter was 100% efficient. DC-DC converters are usually nearly 100% efficient so you'll probably need about 1A from your 5V supply.
Can I find a constant current driver or mosfet driver available off the shelf? I do not have much electronics building experience.
abrahamw88:
Can I find a constant current driver or mosfet driver available off the shelf? I do not have much electronics building experience.
Yes, forget the constant current, that is not what you want...
https://www.aliexpress.com/item/1005001350609565.html
You will need a 20V DC power supply.
Can I find a constant current driver or mosfet driver available off the shelf?
Of course you can. They are industry standard. Solenoid valves are current controlled, not voltage controlled.
There are several reasons that industrial proportional valve controllers use PWM constant current drivers: you can use higher supply voltages for faster response, control valve heating and dithering the valve leads to much more accurate control.
The same principle is used in all microstepping stepper drivers.
Thank you for the replies. This from amazon appears to be the same mosfet driver, correct?
And just to confirm this device would require a 20V supply at the Vin +/- and would output 20V at Vout +/-? The Vout would vary current depending on the pwm signal (5V from the arduino) at the J1 pwm/trig/ground contacts?
abrahamw88:
I am just trying to figure out how to boost the voltage/current available. Thanks in advance!
If you told us what is the voltage available?
The arduino outputs a 5V pwm and I got a 24V power adapter. But I can get any voltage power adapter.
abrahamw88:
The arduino outputs a 5V pwm and I got a 24V power adapter. But I can get any voltage power adapter.
So this from amazon will PWM-chop the 24V voltage to control your valve like it should.
The on-current is yet determined by the valve.
The average current is the on-current * PWM ratio.
Thank you everyone. The mosfet power driver module appears to be working as desired!
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