I am working on a Project that require something very simple. Is actually so simple that I’m more worried about getting it the most efficient way (less price with better solution).
The project require a signal to turn ON a 24DCV solenoid valve for approximately 3 seconds and then shut it OFF for 15 seconds and then repeat indefinitely until the user shut the system down. I was also thinking on making this time 1 and time 2 adjustable with a potentiometer.
The first solution came to my mind was to use a LM555 but I’m not sure if I can get that big times in-between oscillations and also that difference between ON and OFF.
Another solution I thought about (and I’m sure will work) is to use an Arduino UNO to send the signal to a relay. Then I start to think in the cost of an additional power source for the Arduino (5 to 12 VCD I think) and also remembered that the LM555 doesn’t use 24VCD either.
I’m only a beginner in this electronic stuff but I’m also sure that there is some kind of a timer that does what a need, the problem is that I don’t know where to start looking for.
Thanks for your help and taking the time to read all this.
Best Answer
I think for whatever control circuitry you end up using, you are more than likely going to need a second lower voltage (step down the 24VDC to 3.3-5VDC). So, if this was my project, I'd probably use a simple microcontroller. An Arduino board would work. This would be the easiest way to control the valve using timers and potentially having a pot to select different time delays. You could even throw in an LED for when the valve is on/off.
I just did a quick search and came across this: http://www.instructables.com/id/Controlling-solenoids-with-arduino/ Not sure how well it is designed but it could be a starting point for you.