i have some issues on my OSPI.
i have the 24v-ac version and power the pi via the opensprinkler.
on the outputs i have 3 valve’s and 4 relays.
the valves are for the water, and the 4 relay’s are there to switch other device’s.
now i have the problem, everytime the relay is powered on, i get a noisy ripple on the 5V rail on my pi.
when i powered a valve, i dont get these ripple.
the bad thing is not that the pi reboots, but other electronics reboot’s.
these devices are motion detectors.
i tried to power the pi over the external usb with 5V but it make no difference.
yes i desoldered the fuse on the opensprinkler to disconnect the 5V rail to the pi.
the usesd relays are “Finder 19.21.0.024”
the ripple is about 2.5V to 3V.
as you can see in the picture.
As the user manual suggests: if your run OSPi with RPi 3, you should consider plugging in a microUSB cable to power RPi 3 additional using a USB adapter. Because RPi 3 can draw a lot of current that exceeds the design spec of the current batch of OSPi, providing additional USB power will stablize it. I’ve mentioned a few times on the forum that RPi 3 was released after the current batch of OSPi was manufactured, so it’s really not something we could have predicted.
Another work-around which generally seems successful is to solder a wire or 0ohm resistor to bypass the 3R3 (3.3Ohm ) resistor on the lower-left side of the circuit board. This resistor is there to limit the current draw, and you can bypass it to increase the limit.