AC24V solenoid

Is it a good idea to drive 24VAC solenoid valves with triacs?

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I want to build irrigation system for my garden. Most solenoid valves for that purpose work at 24VAC.

I’m wondering if I could use triacs to drive them. They are cheap and small (in comparison with relays) but I have some concerns about overcurrent and short-circuit conditions (like coil interturn short circuits, cables damaged by rodents etc.) and voltage drop (relatively high at 24VAC).

I don’t want to reinvent the wheel.

How this is done in commercial irrigation systems? <- edit: is this question opinion based?

Relays, triacs or maybe something else?




edited 13 hours ago

asked 13 hours ago

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  • Not opinion based imo. – Drew 9 hours ago
  • I thought most solenoid valves use 12V or 24V DC, and for either DC or AC no one is using traics. Can you let us know the links to the applications you mentioned? – tlfong01 9 hours ago  
  • 1The residential irrigation controllers I’ve had have used TRIACs to drive the valves and AC excitation. – Kevin White 9 hours ago 
  • I echo what Kevin says. A 16A triac is cheap and you’re probably not likely to have anywhere near 16A available from the supply, so it should be pretty robust. You can use polyfuses to limit the current. Relays can be sourced cheaply as well but make sure you put a varistor across the solenoid as relays don’t switch at zero crossing. – Kartman 7 hours ago
  • @tlfong01 Take a look at Rain Bird GB-R Sprinkler Valves for example. In systems like this everything is powered from 24V transformer for safety – Kamil 3 hours ago
  • @KevinWhite I think that could be an answer. – Kamil 3 hours ago
  • @Kamil: Thank you for your reference. The AC vs DC power issue seems more complicated than I thought. I need to google harder to convenience myself that (1) AC24V power is better than DC12V, (2) Is it OK to use triac (or SSR, Solid State Relay) to control an AC24V solenoid valve. (3) References: (a) Understanding 24VAC Sprinkler Valves – ray, rayshobby.net, 2014aug22: rayshobby.net/wordpress/understanding-24vac-sprinkler-valves, (b) Solid State Relay: en.wikipedia.org/wiki/Solid-state_relay (4) Solid State Relay en.wikipedia.org/wiki/Solid-state_relay – tlfong01 1 min ago   Edit  

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