View the updated project log on my personal site, XodusTech.com So now that midterms are over and spring break just right around the corner I say to myself. Self: What would be something cool to add to your car... Wings of course. But then I remember that it would be nice to afford food for the next few years and I think a little more on budget. The budget I always aim for is No Additional Cost, and to that I will stay as true as possible. Phase I: Preliminary check of Inverter and circuit design Now to the mod. I decided that since I take quite a few road trips in my car it would be quite cool to have an actual AC socket somewhere. I already have an AC inverter and while it is quite a convience the sound it produces is less than disirable. This particular unit kicks out 350 watt with a 700 watt peak. Its not the most expensive one by far but it does power most things I try to use with it. Laptop's, Cell phone chargers, my Dremel, and most importantly my soldering iron. With that said it was time to start taking a look at the values and getting a little more technical with the device to figure out how feasable the actual idea of locating it somewhere in my car that it could be remotely turned on and have remote status indicators to let me see if it is on and debug any problems.... So the first thing I did was well... take it apart This is the unit itself. Its a little worn from years of use Front and back shots of the unit. Showing the power input spot where I can power it directly off my Car's battery, and the fuses and fan. On the other side are two electrical sockets (wired on the same circuit internally) the status indicator LED's and the power switch This is a shot of the unit all taken apart. Not all that complicated and everything that I could want to solder and modify will be quite easy to do inside this case with the ample room I have. The first thing I need to know about this unit is how much power it takes up when it is on and doing nothing. Not that this information is incredibly useful it is just nice to show the difference between the on and standby states that this unit has. Above you can see that when the unit is on and nothing is plugged in the current draw in amps is about .60 . However when the unit is off the current draw is .00 . Quite as you would expect huh? Well dont jump the gun on that. Upon further inspection I find that the power switch uses some really thin wire compared to the power input and output wires. This means that the unit actually uses solid state or a non-mechanical means to turn itself on and off. If anyone has ever installed a car audio sound system you are quite aware of the REM line required to turn on most speaker and subwoofer amplifiers. Generally when you want them on the line is pulled high to 12v. In this units case there is no specific wire that is either pulled high or low. You just simply ground the two small wires together and the unit powers on. Now if you were paying attention you would know why it was important to make sure there is no current draw while the unit is off. Since the unit more or less sits in standby all the time when power is applied. This is key because when the inverter is wired into my car I will provide it with direct access to the Car Battery. So if the unit was drawing current while off... well then my battery would go dead. Just for fun I plugged in my soldering iron and decided to see what the current draw was with just it plugged in and the unit on. Oddly enough the draw was only 2.76 Amps. The iron itself is a 30watt cheapo (my favorite) and the current draw on the battery was only 12v * 2.76a = ~33.12 Watts. Not very wasteful at all. At least at low power usages. I am sure as you use a device that draws more current that the efficiency goes way down. But its doing an aweful lot just to make 110v out of 12v... Now the next picture is important back on the topic of the power switch. After I found out that the device turns on via a solid state method I needed to know how much current actually flowed across those wires to know what kind of wire would be suited for extending that switch. I found out it is a mere .21 Amps... Perfectly suited for something like thin ethernet wire or the likes. Here is a quick diagram of what I want to have happen. Everything to the left of the blue line would stay under the hood. Only the essientials basically a front end would be on the inside of the car. Thanks for taking a look. I would love to hear any input.