# PWM intensifying

Hello everyone,

I have to control a solenoïd valve proportionally using a 166Hz PWM signal. The resistance of the coil is 2,5-4 ohm. If i'd be using a pure DC signal I'd have around 8 amps of power. However this is an oscillating signal. Since a coil resists changes in current, the effective current will be higher I guess?

I want to create this signal using a digital output in Labview. The problem is that I can only draw a few milliamps from the output. Is it sufficiënt to intensify the signal using a transistor or mosfet? Or do I need to find a complete printed circuit with filters,...?

berkeman
Mentor
Hello everyone,

I have to control a solenoïd valve proportionally using a 166Hz PWM signal. The resistance of the coil is 2,5-4 ohm. If i'd be using a pure DC signal I'd have around 8 amps of power. However this is an oscillating signal. Since a coil resists changes in current, the effective current will be higher I guess?

I want to create this signal using a digital output in Labview. The problem is that I can only draw a few milliamps from the output. Is it sufficiënt to intensify the signal using a transistor or mosfet? Or do I need to find a complete printed circuit with filters,...?

Usually a solenoid will be ON or OFF. What is tue purpose of the PWM?

And yes, if you want to use LabView to generate the PWM, you will need a power amplifier. What is the solenoid coil voltage? Can you post a link to the datasheet?

Averagesupernova
Gold Member
Usually a solenoid will be ON or OFF. What is tue purpose of the PWM?

And yes, if you want to use LabView to generate the PWM, you will need a power amplifier. What is the solenoid coil voltage? Can you post a link to the datasheet?
While I am not 100% sure of the type of valve, there are electrically operated valves that are proportional. More voltage gets the valve farther open. Known as proportioning valves. Common on hydraulics nowadays.
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As to the original question, you will need some type of driver. I would assume the manufacturer of the valve would offer you something. That is if it is a true proportioning valve.

Charly Segaert and berkeman
The valve works on 24V and has the function to control an amount of flow, so it is indeed proportional.
Sadly I do not have a datasheet of the coil, it's used very often on high pressure pumps of Bosch.

So I need to search for a drive instead of only using a transistor?

Thanks