I am permantly installing a pc in my car and need a little electronics help. I have the pc connected to an inverter. Before this past weekend I had the inverter powered direct from the battery. This weekend I decided I wanted to create a circuit that would allow the comptuer to shut down(properly) and then the inverter shutdown all automatically. Anywho my questions are on the part of the circuit dealing with the inverter, relay and diode. I'm using a 30a rated relay. I have 12v acc coming into the relay and I have 12v from the computer itself coming into the relay. The reason for this is if the computer is on I want the inverter to stay on so it won't just power off the pc improperly. So I need to isolate these two (+) triggers and since I've never used a diode I don't know how. I'm pretty sure I connect both positives to the anode side and from the cathode side run the leads to the relay. My question is if I have two diodes with plenty of metal showing won't that pose a problem? Can I tape the two diodes up completely so the metal isn't exposed or will this effect it's performance? Also I'm working in a cramped environment so can I trim the metal stems down to make them samller? Lastly when I run the leads from the cathode side does one lead have to connect to the other cathode side before running it to the relay like the diagram on this link https://www.the12volt.com/diodes/diodes.asp or can I just run each of the leads straight to the relay from the cathode on.
I know this is long and I appreciate any and all who try and help me out here.
thanks
Question.. how does the computer turn itself (and the inverter) on?..
I don't know that I'd want to hook ACC 12+ and the computer +12 together..
I'm assuming that you're 12v from the computer is coming from the power supply, not from something like a printer port. I would consider using an opto-isolator to isolate the computer from the car's electrical system.
Give some more details..
Jim
yes the 12v from the computer is coming from it's power supply. the diode is what I'll be using to seperate the electronics. as a matter fact the computer is powered off of the inverter so it's really completely seperated outside of this circuit I'm trying to get right. Here's how it works. Turn ign to on position....12v from acc line starts and opens path for the 12v+ battery current which starts the inverter(stays switched on), which in turn starts the pc(wake on power) which starts the 12v from the ps. Like I said the 12v from the power supply is to keep the relay energized so that if the key were turned to the off position the inverter won't shut down therefore causing the pc to shutdown because of power loss and not shutdown properly. I can explain the automated shutdown if need be, but that really has nothing to do with my question. Still I don't mind explaining I just don't want to be giving out useless info no one cares about. Anywho any suggestions?
You know you could simply install a switch with a relay, instead of having it controlled by the ignition.
That is the most effective and simple solution to this Q, unless I am missing something here.
Just my thoughts on that.
Regards
EVIL Teken . . .
Well I was trying to avoid a switch. I wanted the whole process to be automated just like my headunit. The way I've placed the inverter(center console) would eliminate the need for me to add in a switch. Anywho I could be mis understanding what a switch with a relay is, but I don't think I am. Last night I went ahead and added the diodes in and taped them. They worked perfectly. That's really all I was going for with my question as I was pretty sure the design would work. Thanks for the help guys.