Is this a good idea to control a inverter based system?

**HiJackZX1** · 10-02-2011, 05:35 PM

Starting to near the finish line for getting my install into the car. My setup uses two systems, one that is controlled by a OPUS 320, then another that uses a 600 watt inverter. Here is where I run into issues. The OPUS 320 controls the power on for the inverter via a relay. Then a small solid state relay powers on the mobo by simulating a button press. Problem is shut down. The OPUS 320 based system is much faster and shuts off quickly. Since it controls the inverter via the OPUS it would cut power before the second system has a chance to fully shut down. My idea was to use a second relay that is on the 12v rail on the second system that also controls the inverter, so once the first system turns off, the second system maintains power till it shuts off. My question is, will I have to worry about possible damage in an way shape or form?

Also added the step down converter for all the hubs. This also has to stay on for both computers.

**theBlueLight** · 10-06-2011, 03:24 AM

I didn't read your post properly, and nearly replied:
'Why don't you use another relay triggered by the second system's power on state (power light or something) hooked up to the 12V rail that supplies the invertor...'
But no, you're there already. I don't see any problem with that, it would just be like having a redundant light switch in your lounge-room to save you having to walk across the room in the dark to turn the light on.... If you wanted to be a little tricky you could just use the one relay and seperate the trigger from the Opus and the trigger from the second system with some diodes. Might work. Might not, who knows?

**HiJackZX1** · 10-06-2011, 01:49 PM

Originally Posted by theBlueLight

I didn't read your post properly, and nearly replied:
'Why don't you use another relay triggered by the second system's power on state (power light or something) hooked up to the 12V rail that supplies the invertor...'
But no, you're there already. I don't see any problem with that, it would just be like having a redundant light switch in your lounge-room to save you having to walk across the room in the dark to turn the light on.... If you wanted to be a little tricky you could just use the one relay and seperate the trigger from the Opus and the trigger from the second system with some diodes. Might work. Might not, who knows?

I went with 2 relays because I didnt want the PSUs to bleed into each other accidently and damage anything.

**theBlueLight** · 10-06-2011, 09:01 PM

Originally Posted by HiJackZX1

I went with 2 relays because I didnt want the PSUs to bleed into each other accidently and damage anything.

A couple of small signal diodes should prevent that. I don't suppose it really matters in the end.

**OldSpark** · 10-06-2011, 11:35 PM

Eh?

Use one relay. Connect both Opus & PSU signals via diodes to the single relay.
(Assuming I understand your diagram...)

**Mickz** · 10-07-2011, 12:10 AM

**OldSpark** · 10-07-2011, 02:23 AM

Yep, that's it.

The diagram is a bit complex because you show the grounds which are all the same in practice and normally omitted. (Even if not the same - except where that detail matters.)

And sorry BlueLight - I missed your reply. I wasn't eh'ing you ay!
And nice HZ. The last of the real pannos!

**theBlueLight** · 10-07-2011, 03:43 AM

Thank you. Surprisingly large numbers of them still around though, once you get one you just can't let go...

**HiJackZX1** · 10-07-2011, 07:11 AM

Well that really simplifies things, but what is a diode? I know its a little circuit thingy, but how does it prevent the PSUs from bleeding into each other. Also in the picture, is there one diode or two? Thats why I went with a two relay because I have never worked with diodes.

**Sonicxtacy02** · 10-07-2011, 08:30 AM

A diode will prevent current from traveling reverse stream back into the alternate power supply. It isnt mission-critical, but its a good idea to protect the circuit with one.