Hydraulic SYM

Many thanks for you constructive response.

I shall learn a bit more about PWM and try what you say

so, you saying that I can send a 0-5v signal directly from the Arduino to the SMC Controller?

I think that as you say I will have to draw up what I want to achieve and really try out with LEDS oil a breadboard before hooking up too the valves again.

I have another two more amplifiers on the way from Australia so I will try again with my pot just to ensure that the coil is working as it was before just using the manual pot. Then I will build a small circuit with the SMC3 as you suggest.

Best I get a few SMC3's

M

hiya

attached you can find a quick sketch of what I am trying to achieve. basically my objective

I will draw one up quickly of what in have done to make the cylinder move with the pot and another showing what I have done too blow up my amplifier

If you want to go your way maybe just use rc servo on your pot.

24v coil on valve? thought they are +/-10v

Hi Again

Attached is a diagram of what I have done top make the cylinder kinda work with a. manual 10k pot and the VEA250, however I noticed a bit of temperature irradiating from the board...

And Hi again..

Attached is the diagram of what I have done with the Arduino/MCP4131 that blew up the Amplifier

NO

The valve is 24v.. At Least the original Electronics was 24V Fed.

The -10v <> 0 <> +10v is the signal that the original Atos electronics required to make the Cylinder move.
Also the Feedback device attached to the cylinder also outputs a 0 -10v signal depending on it's position.

This is why I bought the VEA250.

The VEA 250 is what connects to the Actual Coil and Controls the current and modulation I imagine, making the coil move backwards and forwards, faster and slower.

I then control the signal with my pot on the VEA250...

This is the reason why I though... well, if it works with a manual pot, all I need is a digital one that I can control with Arduino, hence the MCP4131..

Does it make sense now?
]
Cheers

M

Right...
Just been to my SYM doing some measurements and I am officially confused...

Basically i decided to do what i should actually have done before I started this project and was to use the multimeter with the original ATOS Valve controller

I rigged it up as it was originally, and to my surprise my multimeter measures 20V AC across the coils and 5.7 to 6V DC AT THE SAME TIME???

How is this possible?

Is it my meter that is mad?

So, assuming this is possible, how can my VEA250 be operating the valve when i adjust the pot is it's sending 24v DC Directly to the coil????

I really could do with an electronics expert opinion of what can I do moving forwards..

Can I use a rectifier bridge and some resistors to bring the voltage down to 20V AC and replicate the original ATOS Valve.

Thanks everyone following..

Cheers

Marco

Looking at the specs for the vea250 and altos valve.
Max output of vea250 1A@24vdc
Altos valve coil although it is unclear wants about 2A@24vdc.
Not really surprising that the vea250 burnt out.
The pneumatic vea250 controller isn't suitable for your hydraulic proportional valve.

I think the best way for you is to treat the altos valve coil and transducer as a motor.

You cannot treat the solenoid as a motor, the coils need specific controllers to operate properly.
For one, solenoids needs to have dither applied. https://www.qualityhydraulics.com/blog/what-dither-versus-pwm/

Thank you for pointing this out. Was indeed very lame of me not realising about this.. now I have three VEA250's of no use to me..

One thing I learn with them is that they do generate a signal that indeed controls the valves so i am confused as to what signal is that.

Measuring the Atos valve controller output ( Solenoid cords) with a multimeter i have 20v AC and 5V DC at the same time.. how can this be?

if anyone can help me it would be appreciated.

I have 3 months to vacate the warehouse where my sim is and would like to have it working before then as otherwise is going to be trouble to find another place i can have him and work on it...

Cheers Guys

Thanks Alexey

yes, this is what i tried initially and didn't work, hence me looking for proportional valve controllers.. just a shame i bought the wrong ones

The AC you are measuring is probably the PWM signal, the 5v DC would be the average voltage caused by the duty cycle of the PWM.

See if you can find yourself an old/cheap oscilloscope. It will save the headaches and tell you what is really going on.

Ha..

glad you mentioned that.

I just got one.. not sure what i was thinking but I just got a TDS3052 500MHZ oscilloscope.. The sad thing is that i have no idea of how to use an oscilloscope, so is like learning how to drive on Ferrari..

It should arrive this week, so i will try and learn how to use it and let you know what I get..

youtube is your friend

When you get it, post a photo on the forum and we can get you started.

You got me stumped there @Alexey.
Both motors and coils are inductive loads, h-bridges and half h-bridges are NOT exclusively used for motors only.
In fact most bridge drivers will say it is designed for inductive loads which includes coils and solenoids.
So called dithering is not a 'must have' but an option, anyways not too hard to implement as you could use something like AM modulation to superimpose white noise to the power supply.

@Marco Dias
The biggest advice I can give you using your oscilloscope to not put your ground clip on any bipolar signals which includes your amplifier output or h-bridge.
Why? well you will get a signal going one way but once it reverses, your ground clip will cause a dead short.
If you want to check amp or h-bridge output on the scope, use 2 probes and connect a probe to each output. Connect one ground clip to the -ve supply.
I usually invert one of the channels so I can see polarity reversals.

One other question, does the coil on your proportional valve have 3 wires or terminals on it?

PS you will need to be patient with me, as I don't really come here much nowadays

You are correct, but it's much like saying ABS is not a "must have" in the braking system of a car. Not having dither will not mean that the solenoids won't work but you may have issues with stiction. Stiction is where the valve won't move as desired due to static friction in the internals of the valve. If the internals are all nice and clean then there shouldn't be any issues or at least not any noticeable issues. Situations where you might notice stiction would be during small movements, it could also just manifest as noisy/popping vavles. Or your valves could be designed as such that there is no stiction and you don't have to worry one bit. I have heard of anti-stiction additives being used in hydraulic systems.

I suppose you won't really know until you get the thing working, just keep it in the back of your mind.

Thanks m8..

Got my oscilloscope, and bought two 500mhz probes for it and I have to say I have got no clue on how to use it..

Not even sure if buying the 500mhz probes was a good choice or not.. I bough it because my oscilloscope TDS3052 is a 500mhz oscilloscope..

Anyway, I am really lost at all this and really wish I could understand more..

I am gonna try and find someone locally that can help me with the scope so I can try and give you guys some information you can use..

Taking it as a completely lame and newbie approach, is it right to think that if I did manage to move the actuators backwards and forwards =, faster and slower, with the only downside of the vea250 getting real hot, I am in the right path?

I would imagine that if somehow the VEA250 wasn't doing some part of a good job, the coil inside the valve would either not move at all or be a; over the place oscillating... no?

'I have a basic understanding of power and current and this is where I am basing myself with my assumption..

I don't really know what most of the terms employed by you guys actually mean .. I just want to kind figure out on how to efficiently use the valve now that the original electronics have been damaged...

If you could somehow help me I would appreciate :/0

In reference to your question of how many cores I have, the valve has two cores which is the actual coil cores.. thicker coils and a small ribbon cable with thinner cores which I imagine us feedback/position.. I am not using these and I don't need positioning on the valve itself as I have a different feedback system on the actuator...


Look forward to her your thoughts on this...
'Cheers

Marco