I searched around and haven’t seen my issues elsewhere. Apologies if this has been covered already:
I have had some issues getting my Spark 4 with GPIO expansion board to control a 24VDC ball valve (AW1 actuator 24V DC relais (AW1-R024DC) - Tameson | Tameson.nl). The valve is intended to control glycol cooling on a fermenter.
My math may be wrong, but as the ball valve uses 3W of power at 24V, I think it only needs 0.125A to function. With this in mind one channel/pin on the GPIO should be enough to control the valve. I have it wired as follows:
Black and Brown are connected to an external 24VDC supply which also powers the Spark 4. Blue is connected to one of the GPIO pins. The GPIO pin is set to supply external power (24VDC) and to be + only. When I measure the pin with a multimeter I indeed see that when I set my desired Beer Temp lower than the current temp, I get 24V across the pin. When the desired Beer Temp is higher than measured the voltage across the pin is 0V. I measure across the GPIO pin and the Black line as ground. So far everything looks good!
Then I connect the Ball Valve and it goes wrong… When I try to trigger the Ball Valve nothing happens. If I disconnect the Ball Valve and measure across the pin, I measure 0V when it should be 24V. At first I thought I blew a pin, but if I power cycle the Spark 4 and measure again (without connecting the Ball Valve) I get the expected behavior of 0 and 24V. Until I connect the Ball Valve again and it fails again.
I have tried using other pins on the GPIO and have even connected 4 pins in parallel to get 4A of current. Same thing every time. When I test the Ball Valve with only the external 24VDC power it works as expected. I have tried to set the channel to be a Motor, SSR, and Solenoid. No difference there.
I suspect that there is a surge protection or something going on in the Spark 4, but I am quite a novice when it comes to things electrical. Any support would be greatly appreciated. Thanks guys/gals!