Choosing pneumatic solenoid, AC or DC

[FiveO]

Hi

There are mixed information on these on google. I want speed(low lag) first, valves will be open and closed 1-2 minutes.

Controlling them with Arduino or ESP with relays.
Do I get this right?

AC 220 - controlling them with Solid State Relays
+ Speed of Solenoid with AC is faster than DC
+ Can use Solid State Relays, these are faster than mechanical relays and voltage spike free
+ No need of additional power supply
- Humming noise

DC 24
+ More silent than AC, don't hum
- Slower than AC
- Must use mechanical relays, are slower
- Need additional power supply

With this info I want to choose AC 220, is this correct? What setup makes lower electrical noise?

 

[Tom.G]

Your request is a bit confusing. You talk about valves then solenoids. Are you referring to electrically operated valves or mechanical valves you will operate with a separate solenoid?

Unless you have a VERY unusual requirement, I suggest electrically operated valves.

Your requirement for low lag time will be dominated by the time it takes the valve to physically move, the time for the down-stream plumbing to pressurize, and the time for the it takes for the actual load to move. Of course this also applies when the valve is closing.

Your statement of + Speed of Solenoid with AC is faster than DC is counter to expected.

I would expect slower and inconsistent speed with AC. This is because Solid State Relays (SSR) for AC often wait for the Zero crossing of the AC before they switch, yielding an inconsistent delay of up to half an AC cycle.

If the AC SSR enforces Zero Voltage Switching (ZVS), that could be the lower electrical noise, although it depends on the load type. The electrical noise for either AC or DC can be greatly decreased with some arc-suppression circuitry at the load (solenoid), or to a lesser extent at the SSR.

If a mechanical relay is used, arc-suppression may be needed at both the load and the relay. This is because the relay contacts tend to bounce when they close.

There are DC to DC solid state relays that can handle DC at 0.5mS switching speed. For instance:
https://www.futurlec.com/Datasheet/Relays/HFS33.pdf
DC relay found with:
https://www.google.com/search?&q=ssr+100A+dc+datasheet

Cheers,
Tom

 

[sophiecentaur]

Your statement of + Speed of Solenoid with AC is faster than DC is counter to expected.

I'd imagine it's likely to do with the inductance of the coils in both cases and applies to the particular samples being dealt with.

 

[anorlunda]

@FiveO , can you explain more what your project is? Your high speed requirement sounds strange and unusual.