What do you do after two relays get busted? ...

[WoodsieLord]

... you build your own relay out of scavenged stuff, but of course!



So, I started from an HP laser printer solenoid. I attached it to a plastic scrap.


I'm a fan of two components glue, as you can see. The contacts are small pieces from the smaller saw blades. I applied sand paper and tinned them.


Seems to be working...



Yet, when disconnecting it you can see an arc. I think I should reinforce the spring to make the disconnection faster...
I'm on a tight budget right now, but I was planning on getting one of these:


...What do you think? Sounds reasonable ? Should I be fighting cold with a straitjacket in a soft room? Let me know!

 

[Craig]

I've had mixed results with the stinger they get hot as well but how hot is the question. Are you trying to control your Inverter it Charging?

 

[WoodsieLord]

I'm short on panels and I'm short on batteries. I wanted to utilize my current installation in a way or another, so what I'm currently doing is this:
When there is sun, I switch OFF my UPS's AC input. This starts to drain battery. This is done by a relay controlled by one of the Raspberries by cutting the AC wire going IN. At the same time, a more powerful relay connects the array to the S.C.C.
This way, the S.C.C and the UPS power supply should never fight to recharge the bank. If both sources charge the battery bank at the same time, I can hear an unpleasant hissing from the UPS, so I think it's not healthy.

Each minute, a script checks if the Solar power is producing enough to satisfy demand (so that batteries don't drain). IF solar cannot satisfy, it rolls back to AC by disconnecting the panels from the charge controller then reconnecting AC to the UPS's input. Then, it waits some time (currently I'm experimenting with 30 minutes) to try again by cutting AC, enabling solar, checking, etc. etc. etc.

My god, if I had bought an All in one MPPT+inverter solution to start with....... I would have energy but it would be SO boring! Right? ... just kidding! Although the learning experience justifies it for me !

Thanks and regards!