Hi.
We made some arduino based electronic that reads rpm on one motor and triggers relay, based on motor speed.
After some problems with turck sensor, finally it works. So, i was thinking OK this is done,.... but
We have hooked up outputs from relay board to 12V hydro pack solenoid valve ( btw. this valve needs 4-8A to run ) and now the funny part. When relay triggers, LCD on arduino starts to blink. In other words, each time when relay triggers, LCD makes blink. GND of arduino and negative pole of valve are hooked together so there should be no problems in this part. When i disconnect connector that goes to hydro solenoid valve, everything works OK.
Summary:
2 relay board - 12V / 10A relay
hydro-pack solenoid valve mounted on quite big iron pedestal
arduino uno with lcd display
main power supply, stabilized 12V / 10A , AC/DC adapter
At the moment i have no idea what could be a problem, because main power supply is enough for solenoid valve and relay can trigger this so there should be no problems. I didnt connect GND of this relay module with arduino board because i dont think its necessary but if needed i can do that too....
Any comment is welcome.
A.
Powering an LCD from any source shared by any device that draws substantial current requires some
counter measures because a relay or solenoid will generate spikes on the power rail that will cause
garbage characters and blinking on an LCD. This can only be eliminated by having a separate regulator
for the LCD and using a large enough electrolytic capacitor on the output of the regulator to prevent the
affects to the LCD. Decoupling caps will help but not enough without the additional regulator and cap.
Sorry guys for late reply.
12V/10A relay is opto isolated and after i have disconnected the middle wire from valve ( mass ) electronic is working OK. In fact, it has worked without any problems for an hour but after that one of the relay stops to work. The relay that stopped to work is the one that was active most of the time, in fact 90% of time. IMO it has to do with the current that is drawn from valve because at some point valve start to use oil and i guess that in this moment current is bigger then 10A. -- I dont know if this is smart but i think it would be better to avoid relay and use transistor approach ?
