Controlling home sprinkler system

Hi there,

I have been reading up a lot on controlling solenoids from the playground and various websites. I want to be able to control my sprinklers from a website.

My solenoids that I need to power has the following specification:

• Solenoid: 24 V ac • Inrush volt-amp: 24 V ac-11.50 VA • Inrush current: .4 amp • Holding volt-amp: 24 V ac-5.75 VA • Holding current: .2 amp

Is it still advisable to make use of an separate 24V AC PSU and use opto-couplers to switch the solenoids? Or would using transistors be a better option?

Since you are using 24volt AC a Traic would be needed and not a transistor. Traics are used to switch AC devices. Watch this video it has a circuit. I like the MOC3041 because it fully isolates the micro controller from the load. Don

Hi there,

Would the MOC3021 also work? What is the difference between this and the MOC 3041?


It's a triac google both part numbers and compare the voltage and current limits etc. You want to use this 6 pin chip to drive a larger current capable triac. you will not need Q1 since a Arduinio can drive a simple led. Don