Need help turning 9V solenoid valve on and off wirelessly. The valve opens with momentary pulse of 9V+. The valve is closed by reversing the polarity and another 9V pulse. If I were doing this old school I would use 2 relays with 2 pushbuttons one wired to open the valve and one to close the valve. I have the xbee's I plan to use for various other sensors. I would like to power the Xbee from the 9V battery. What circuit and components would be best from the xbee to the solenoid valve?

 

What sort of signal (analog or digital) are you transmitting to the Xbee? Will you be using a microcontroller?

Assuming you can get a momentary "on/off" from the Xbee, that will be at 3.3V or maybe 5V, if you have an adapter board. You could probably use a solid-state relay (SSR) to operate the valve, or you could make your own SSR using logic-level mosfets. I suspect you will have more success using a microcontroller from the Xbee, which would then drive the SSR or mosfets.

A 9-V battery will provide about 500 mAH of current. Your total current draw will be in excess of 50 mA (Xbee alone draws about 50 mA). If this device operates continuously, you will need to change the battery frequently.

John

 

The solenoid valve will only operate one time per week and I could add a solar charger. On the valve end of the network I will also have some additional sensors. I will have a microcontroller on the base station end of the network. I can buy a relay shield that would work on the valve end but thought building it myself might be much lower cost.