I am working on a project in which I have to control 3 different proportional solenoid valves. I have never worked with solenoid valves before, at first I thought proportional valves could be controlled with a simple square PWM but I have doubts : is it possible that some valves need a specific controller, or be current controlled?
If we take a look at the datasheet of the 3 valves I need to work with, the way they are controlled is not clear to me :
The first one is 6252AD02L0A00F1, the datasheet is here :
It is a block of 3 valves, 2 are direct and the last one is proportional. The only information we have is : " Proportional valve (P): 70 – 220 mA (24V) "
Does it mean that it should be controlled in current? How is it generally done?
The second is H226A546S0A00F1, the datasheet is here :
There is very little information on the way it should be controlled. Is it possible to deduce it from the datasheet?
The last one is SCG202A204V 24/DC, the datasheet is here :
It is stated : " Voltage regulation 0 - 24 V DC. 24 V DC pulse width modulated (400 Hz) ".
Does it mean that a standard square 400 Hz PWM is enough? If so, why do they propose to use a controller : "E908A003" (datasheet : https://www.emerson.com/documents/automation/european-catalog-electronic-proportional-control-unit-908-asco-en-5044452.pdf) ?
Thanks a lot!