Looking for IC to drive 5/2 Solenoid

Thread Starter

Soham Patil

Joined Aug 31, 2019
17
So how is the valve returned to its default state? Spring return? Air pressure? Other?
Its a bi-state valve. Powering one coil will take it to one state, powering the other will lead it to the other. Removing power doesn't alter states, the valve remains in the same position. No default state as such
 

Ian0

Joined Aug 7, 2020
9,671
Its a bi-state valve. Powering one coil will take it to one state, powering the other will lead it to the other. Removing power doesn't alter states, the valve remains in the same position. No default state as such
That suggests you could simply use the ULN2003 and power one coil from each of two outputs.
 

Thread Starter

Soham Patil

Joined Aug 31, 2019
17
I've been looking at a 1 Form A 1 Form B Solid State Relay. Particularly this one
https://www.digikey.com/en/products/detail/ixys-integrated-circuits-division/CPC2317N/3077531
I think this could potentially be a very good solution compared to the previous one.
1679859535172.png

It would be a 1 IC per valve configuration. I'll merge the inputs, and use the outputs to switch 24v on and off on each side. It has the isolation I need, plus 60VDC and 120mA on output, which is more than enough. What are your opinions on this?
 

Ian0

Joined Aug 7, 2020
9,671
Agreed, however I would required 2 pins per valve, and for 8 solenoids that would be 2 whole ports gone
Drive the ULN2003 with a 74HC123 monostable, one half triggered on the positive going edge, and one half triggered on the negative going edge, then you have a self-timed circuit, that won't continue to take power even if your software crashes.
 

Ian0

Joined Aug 7, 2020
9,671
I've been looking at a 1 Form A 1 Form B Solid State Relay. Particularly this one
https://www.digikey.com/en/products/detail/ixys-integrated-circuits-division/CPC2317N/3077531
I think this could potentially be a very good solution compared to the previous one.
View attachment 290769

It would be a 1 IC per valve configuration. I'll merge the inputs, and use the outputs to switch 24v on and off on each side. It has the isolation I need, plus 60VDC and 120mA on output, which is more than enough. What are your opinions on this?
For the price of one of those you can buy twenty-four ULN2003s each of which will run three solenoids, so it's 72x the price.
 

LowQCab

Joined Nov 6, 2012
4,026
I don't know what brand of Valve we're talking about here ......
but with the 2-Solenoid "MAC Valves",
the second Solenoid is to allow faster PWM-Cycling.

The Valves are available with a single Solenoid and "Spring-Return" also,
but they have a slower Response-Time.

The 2- Solenoid MAC-Valves can comfortably run at 20hz PWM Frequency,
this provides more accurate, and smoother, Air-Pressure-Regulation.

The problem with SSRs is that they are "Passive-Devices" which will
require the addition of Spike-Suppression-Diodes to each of the Solenoids.
These Diodes do a fine job of preventing Spikes,
but they also slow-down the response-time of the Valve considerably.

The FET-Driver setup is never "Off", and is extremely fast,
it forces the Solenoid-Coils on AND off,
and automatically cancels the normal tendency of the Coils
to create Voltage-Spikes each time they are turned-off.
.
.
.
 

MisterBill2

Joined Jan 23, 2018
18,176
I have designed many machines with dual coil valves like the picture shows. It is a 5 port 2 position maintained position device.
Both bistable, but far more often, center-off monostable. There are applications for each configuration and they are not the same. Each solenoid can have it's own driver, there is no electrical interconnection between the coils.
So it would help to have a better description of the valve operation, because what it appears to be is a two position, maintained position, valve. That would hold position when power was removed. All it requires is separate drivers, and logic to only operate one at a time.
Given the description of the current driver module it does not seem like any change would be an improvement. It seems like the operation is hold in either position or the other.
For any more help more details of the operation are needed, such as what happens when the power source is OFF, and under what conditions the valve must move and not move.
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
For any more help more details of the operation are needed, such as what happens when the power source is OFF, and under what conditions the valve must move and not move.
5/2 solenoid valves usually have a spring or pilot air return so that when its de-energised, the valve returns to it's starting function.
 

LowQCab

Joined Nov 6, 2012
4,026
It's a guessing-game 'till the TS gets back.
Is it Bi-Stable, Bi-Stable plus default, or PWM, or some other mix ???

I'm still liking my FET-Driver suggestion,
with 2-Devices per Chip,
quiet as far as electrical-noise goes,
excellent PWM capabilities, or Bi-Stable operation, with no special considerations,
and only requiring 1-Input per Dual-Coil-Valve.

If the present setup is Bi-Stable,
and operating a Cylinder/Piston arrangement,
the the change-over to PWM would be easy,
and would provide much smoother Cylinder actuation,
possibly reducing parts-wear and noise.
.
.
.
 

MisterBill2

Joined Jan 23, 2018
18,176
5/2 solenoid valves usually have a spring or pilot air return so that when its de-energised, the valve returns to it's starting function.
The two-coil valves in that configuration were either three-position with center closed and spring return from each side, or two position maintained..
Unless there is some requirement that the valve not move from either position when all power is lost, they can go to a single solenoid spring return valve with exactly the same pattern, and reduce their costs for the valve as well as for the driver. I have designed many pneumatic circuits and I know what I am doing.
 
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