Good morning everyone, I would like your advice, I find myself designing a test machine that I was thinking of controlling with an Arduino.
The following must be connected to the card:
3 accelerometers (1 per axis)
1 Pt 100 probe
Pneumatic valves are yet to be determined
And a system for controlling the number of shaft revolutions.
In your opinion, since there is a bit of budget, what is the best card to manage everything?
I was thinking of the UNO R3/4 or Mega
Do you know what brand there are pneumatic solenoid valves that can be easily controlled by Arduino?
I would think a Mega or an ESP32
the first thing is to draw up a requirements specification
e.g.
specify the sensors, valves, etc, to determine the IO requirements
do you require a smartphone app to control it?
do you require run time statistics uploaded to a IoT desktop?
you would probably require an industralised version of a microcontroller
They are no true analog outputs on Mega. PWM isn't truly analog, but can be used to control certain devices like the brightness of LEDs or speed of DC motors.
Tell the forum what these PWM/analog outputs will be used for and we can advice whether PWM outputs can be used. Nothing in your first post appears to need analog/PWM outputs.
Most accelerometers you can buy for use with Arduino are triple-axis, so you may need only one sensor.
No solenoids can be controlled directly by Arduino. The voltage and currents would damage the Arduino. So you always need driver circuits between the Arduino pins and the solenoids. This can be as simple as a mosfet and a couple of resistors.
If you can select an appropriate valve from a mechanical point of view, I'm sure it can be controlled by Arduino through a suitable driver circuit. Drop a link to the data sheet for mechanically suitable valves and the forum can suggest driver circuits.
Unfortunately my skills are more in the mechanical field, which is why I was asking for your help in the electronic field.
As I replied above, 2 valves are proportional and 2 are not, for the first I was thinking of a transistor, is it possible?
The data sheet, which may be ok from a mechanical engineering standpoint, is pretty useless from an electrical engineering standpoint. It says
24 V DC: 1 W
24 V DC: low-current phase 0.3 W, high-current phase 1.0 W
with absolutely no explanation of what "phase" means. Its DC, not AC, so doesn't refer to AC phase. Maybe it means there are two coils? Or maybe two phases of time?
@fer315 Do you have any idea what it means?
1W at 24V is about 41mA. Even a small transistor like bc337 can handle that
In my opinion they mean:
unswitched state with 24 V, P ≤ 0.3 W DC
switched with 24 V, P ≥ 1 W DC
I have sometimes used solenoid valves and I have always seen them in direct current, intuitively with low currents the coil did not have enough field to switch, I suppose
Why would any power be needed in the unswitched state?
Do you have one of these valves to hand? Was there an installation sheet that might give more clues? How many electrical terminals does the valve have?
I don't have the valve model from the data sheet here, but there should be 2 contacts (24 V, 0 V). With any current less than 0.3 W (even 0) the valve is not switched
I hadn't covered the rest since it's a purely mechanical area and I can't make any changes to it, however, of course, it's a ball bearing test system with the application of axial and radial loads with pneumatic systems that stress the bearing support causing vibrations that must be measured to determine when they reach unacceptable levels, it is also necessary to know the bearing temperature
You will need to know the characteristics of the proportional valves, as they will have a particular PWM frequency that they work at, some actually need a dedicated driver module that you have to send the control output to.
I reread the technical data sheets, the 0.3 W / 1 W valve is not proportional, it only allows 2 states.
The other valve, which is proportional, requires 24 V power supply, driving 0 V - 10 V analog signal with current between 4 - 20 mA
