Having some trouble getting a valve to properly actuate using a 12V relay. The LED indicator on the relay lights up when I send it a signal but the valve doesn't do anything. The valve will actuate when I hook up the leads but is unresponsive to the relay. I've tried switching the positive/ negative leadss.. Tried using normally open and normally closed on the relay and every other configuration I could think of. Any help is appreciated!

Does the relay click? If it does then I'd check the vdrop across the wires. these relays have a significant in-rush measured in amps, probably several. Small gauge wire = big V drop.

 

If it does then I'd check the vdrop across the wires. these relays have a significant in-rush measured in amps, probably several. Small gauge wire = big V drop.

You are thinking of AC relays, DC is whatever the resistance of the coil is.
Max.

 

Just as a side note and not to add any confusion you may want to place a diode to serve as a "flyback diode" across your solenoid. Something like a common 1N4002. Merely a suggestion as I don't see a flyback diode pictured. Cathode to the (+) side of the solenoid input.

Ron

 

The modules are build with flyback diodes. You can see them when you zoom in.

 

The modules are build with flyback diodes. You can see them when you zoom in.

The diodes on the module are across the relay coils on the module. I am suggesting a flyback diode be placed across the solenoid coil. That was my point, not the relays on the board which already have flyback diodes.

Ron

 

There are a huge variety of these relay boards available - they all look similar, but are designed for different applications.

The first step is to get the specs on your actual relay board. There will be jumpers that allow you to select if the relay coils are powered from the Arduino or from an external source. Your pics show that the relay coils need 12 volt DC to actuate (google the part number for full details) so you will need to supply 12 volts to the correct terminals and set the jumper.

Unless we know the exact model number for your board, we really can't help much further.

You should also add a Flyback diode to the solenoid coil as this will send a spike back through your board when the relay turns off.

Perhaps the easiest way would be to just buy another 5 volt version of the relay board as this should work with the way you have wired up the 12 volt version.

Dave

 

If you are using micro to control relays do you need to be able to sense
valve solenoid position to insure it opened or shut when you commanded it
to do so ? Some applications, like life support, chemical processes,
need to know the state of the valve is in as confirmation before doing additional
process steps.

For example valves in hot water systems, with water supply full of minerals,
often stick due to deposits accumulated over time.

Regards, Dana.

 

There are a huge variety of these relay boards available - they all look similar, but are designed for different applications.

The first step is to get the specs on your actual relay board. There will be jumpers that allow you to select if the relay coils are powered from the Arduino or from an external source. Your pics show that the relay coils need 12 volt DC to actuate (google the part number for full details) so you will need to supply 12 volts to the correct terminals and set the jumper.

Unless we know the exact model number for your board, we really can't help much further.

You should also add a Flyback diode to the solenoid coil as this will send a spike back through your board when the relay turns off.

Perhaps the easiest way would be to just buy another 5 volt version of the relay board as this should work with the way you have wired up the 12 volt version.

Dave

Hi Dave and welcome to the board!

I see it is your first post. Hope that you don't think that I am being too harsh, but it is sometimes compelling to read only a part of the thread, before responding. In this case, the original poster, after understanding that they were 12v relays and changing the hookup, solved the problem, back in post #17.

As @Reloadron noted, and I and others originally missed trying to help get the relay working, the diode on the solenoid, is a good point - although I don't know that the OP has seen that since he hasn't logged in since Feb 16.