Hello. I would like to use the load output of the Victron SmartSolar 75/15 controller to operate three 24 V DC coils for three irrigation valves. Is it sufficient to fit each coil with a blocking diode (flyback diode)? Will this be enough to prevent damage to the controller? Many thanks! Idriss
Hello @Idriss
I would fit a flyback diode across each relay. I’d also add a diode on the positive output towards the relays. It’s actually unnecessary, but considerably cheaper than a damaged MPPT.
Dear Dirk.
Thank you for your reply.
Do you mean that the extra diode is then in series with the coil? In that case, it must also be able to carry a large current.
Hello @Idriss
How much current does a valve need?
Any standard diode from the junk box should do.
Output MPPT ->|- diode, relay coil, ground
Hello Dirk.
265mA per coil
3 x265mA = 795mA
Hello @Idriss
That should work without any problems (with the diodes).
You can program the load output as you wish
Good luck
Yes, isolate the relay with series diodes and fit flyback diodes across the valves. That’s how I set up my balcony irrigation system too (don’t forget the pump motor if a low-voltage system is being used and powered by the same system).
Karl
Can I send you a diagram of how I see it?
There is no relay!!! They are three irrigation valves with just a coil inside.
Dirk,
Can I send you a diagram of how I see it?
There is no relay!!! They’re three irrigation valves with just a coil inside.
Good morning @Idriss
you can simply upload the plan here so the others can benefit from it too.
Best,
Dirk
Perfect, that’s how I would have done it too…