arduino to control 0-24V DC

Hello Everyone!!!

and thank you for reading this. I need to control 0-24V DC 2A voltage (not PWM) to a proportional solenoid. What would be the easiest way to do this? Are there digitally controlled 24V power supplies?

Cheers.

Hi,
Can you post a link to the spec/data of the proportional solenoid please?

Thanks.. Tom.. :slight_smile:

Sure Tom :slight_smile:

Basically what it sounds like you want is essentially a "programmable power supply" which is going to take some sort of add-on DAC. They also show on their application page driver boards and rs-232 driver boards which might be easier to talk to. See their application page at Pneumatic Valves, Regulators, & Control Products (you can insert a clickable link using the link tool in the post menu between the "image" tool (looks like a monitor) and the "superscript" tool that looks like "X squared")

i still need an arduino for the driver board and I wanted to save $200 and learn to power the solenoid myself

house231:
i still need an arduino for the driver board and I wanted to save $200 and learn to power the solenoid myself

Which takes you back to the first part of my comment about having to add a DAC (Digital Analog Converter) since the basic Arduino does not have one. What you basically want to do is build a programmable power supply (0-24v) controlled by the Arduino (DAC output). That is the easiest way I can think of - you set the DAC to a proportional value of the voltage you want and the power supply circuit generates the output based on that voltage that you are creating. Somehow you have to get from a digital output to an analog.

thanks Mikey that sounds perfect. is their a dac you like to use???

From the datasheet:

"Voltage Range 0-5, 0-10, and 0-20 VDC"

No experience with this valve, but the numbers tell me that this valve needs a (0-5volt) control signal.
Not a 0-24volt power supply.
0-5volt DC is easily made with a resistor and a capacitor from a PWM output.
Leo..

the valvd needs 20 v, 30w and 1A on the spec sheet . the arduino only ouputs 5v 50ma if i remember right.

These figures 5/10/20V are driven voltages, so you also need to determine the power (watts/amps) for the voltage model you choose
This will then imply a power driver added after the DAC - to handle the valve motor requirements.

:: sorta beat me!

Didn't see this before.

"This driver board converts an input signal proportionally to an output current"
Leo..

the arduino only ouputs 5v 50ma if i remember right.

You do not. An IO pin can output 0 or 5V, with 40mA recommended as an ABSOLUTE MAX and only for short durations.
Currents above 20mA will cause the high voltage level to droop, and the low voltage level to rise.

I wonder if you could pwm a simple 24vdc supply with a big logic level mosfet... -a catch diode and a reservoir capacitor may give a suffiiently smooth DC to work this solenoid... add a series inductor for a better job.. 10mH /4A sat would be OK at 1kHz ( The standard arduino pwm frequency)

A lot simpler than making a clever switchmode psu... which, after all is pwm or variable frquency fixed pulse anyway with l-c smoothing...

regards

Allan