hi all,


so I have undertaken a little audio project, as described here:


https://www.jaguarforums.com/forum/g...hanger-121342/


and I am hoping to get some advice as to what power invertors people use, and how they set them up? like, do you run them direct off the battery and use a relay to work with the ignition switch, or what?


I have a '99 XK8 Conv and I don't know what size I can safely use, (meaning, max AC watts) and whats a good brand, what I should look for, etc... so any and all advice is appreciated.


I think I would be comfortable with (have a goal of) around 250-350 watts.


the price range on these is all over the place. I just want something reliable and robust, but I don't want to just throw money at it. best value.


https://www.google.com/?gws_rd=ssl#q...=vw:g&tbm=shop



I know nothing of brands or really much about this, so whatever you can share would be great!


thx!

 

Hello MrSinatra ... and greetings from Australia.

I sense you may be undertaking these mods without having the JTIS (Workshop manual) and wiring diagrams at hand. Not being critical and I could easily be mistaken, but several of your questions provoke my worries.

Firstly, your audio project to date ... Are you sure that the molex connector carries analogue signals for each channel? I have noted your discussions with Chris [Thermo] but I am somewhat unclear whether all is working OK. I would have expected all this harness to be carrying power, grounds, and purely digital signals (not analogue). No different to the wiring between optical drive and motherboard in your computer, where the old 4pin analogue connection became redundant 10+ years ago. In any event, with JTIS and your wiring diagrams, all is revealed ... including the pin number layouts of all connectors which you can cross-reference with the harness points shown there. I happily stand corrected if all is working sweet and you have your analogue break-in working. Yes?

Secondly, the inverter ... and I assume your purpose in wanting one is ... what? 250-350 Watts? Perhaps you plan a mains powered computer? If so, that's critical to the type of inverter you need. The reason prices for inverters are "all over the place" is because they come in two or more distinct flavours - modified sine wave; cheap and dirty end of range and definitely not suitable for powering sensitive electronics - or, at 2-5 times the price, pure sine wave inverters designed to overcome those shortcomings.

If I may say so, an in-car inverter seems a very wasteful means of driving a sound source that any older Android phone (chuck the sim card, but load it with a 32Gb microSD). Now you are talking +5v from a cig lighter socket and the phone will either have a charger lead or you can buy one for less than $5. A modded ear bud lead gives us the audio out channels. Simple and cheap. What is not simple, but some have overcome, is the lack of an AUX IN (analogue) socket ... which brings us back to where I came in. Suggest you search forums using terms like "AUX IN" or "Linking an iPod", and look carefully for full costs and results achieved.
Best wishes with your project,
Ken

 

hi, thx for responding, I hope to visit there one day!


I should probably make clear that I have a jag expert mechanic, he works exclusively on jags and range rovers, Bentleys, etc, but the mods I am asking for are not his forte. I think he can handle all the work needed, but he doesn't do much in this realm, know brands and so on. so I am trying to figure things out that I can't really expect him to know.


my understanding is the CD changer in the trunk sends ANALOG signals to the head unit. this is a 1999 so either way could be true, but everything I have seen so far makes it sound like it is analog. digital would have been better of course, but I am trying to keep all the orig pieces in place.


it is just one big cable connecting the head unit to the trunk, so there's a lot in it besides just the analog wires. the links in the other thread are very informative, but confusing to a novice like me.


gtk, i'll be sure to get a pure one.



I want a full computer (mac mini or similar) mounted in the trunk, for uses other than just audio, and I don't do music on handheld devices. i'll connect a USB drive or something to the computer to have all my music in the car, which is about 600 gigs worth. in addition, I want an outlet capable of other uses for whatever may arise on a: roadtrip, tail gate, camping, etc.


thanks again for the info. I hope someone else has done a similar project and has some tips, or brand recommendations.

 

Great feedback response MrSinatra ... know now a lot better what you are wanting to achieve ... and why.

(1) Unclear as to whether you have JTIS and Wiring Diagrams so let me offer you a link to a great resource compiled by one of our members, Gus. I tested the link and Gus' XK8 resources (man, are you in for a treat). Please remember to drop him a "Thank You".

Gus' JagRepair.com then navigate your Model/Year/Variant etc.

The wiring diagram page needed for the XK8 Convertible is Fig #16.1, and whilst all the speaker wiring is analogue of course ... that between CDC and Radio/Cassette Head Unit contains a CD Link Lead (IC7-IC8) and an 8-way bus (IC7-1/8 to IC8-1/8). My bet is that this is an 8-way parallel digital data bus ... good in its day, but now looking old hack in view of modern serial comms. Something your man can check. Sorry I can't recommend any brands of translators or bridges you might access locally.

(2) Now knowing you intend to power a laptop, if you do go inverter, then "pure sine wave" is only option and expensive. Can you find and use a laptop designed around a 12-14V internal battery. If so, perhaps you can dispense with inverter; also the laptop charger; then connect permanently your car's supply voltage?
I really do wish you well with your project and will continue to follow your progress.
Ken

 

No, this 8 pin link is the Jaguar version of the Alpine AI-Net: Google Image Result for http://www.mp3car.com/vbulletin/attachments/hardware-development/21766d1131927532-schematics-pin-outs-diagrams-ai-net-cable-diagram.gif

 

Thanks Steve for correction and link to pinout. Tinkle, tinkle ... sound of pennies dropping as soon as I read "Jaguar version of Alpine AI-NET".

Followup question from MrSinatra might now be "Are pins #4 and #6 analogue audio channels with #5 their common ground?"

ATB,
Ken

 

I'm assuming that is the case, but I am planning on getting either a:


Alpine KCA-410c or a PIE ALP/AI-AUX


if I hopefully can find one. my mechanic says I have "premium sound" b/c its a Harmon Kardon system, but idk if he checked for the amp by the CD charger or not.


while I greatly appreciate the feedback, I would like to keep audio issues to the other thread, and keep this one based on power issues.

to that end, i thought your comment about a DC powered computer was interesting, and i found this:

Automotive ATX Power Supplies


so i would have to figure out which one is appropriate, and then find a computer that suits my needs that runs off of 12v. there are a lot of 12v mini/micro computers out there, but so far what i am finding is pretty underpowered esp considering the price. also, i need it to be solid state and would prefer it run windows.

i still want an inverter, but this is a way for me to put that off, and it seems like a better overall solution towards setting up a "carputer."

 

OK MrSinatra ... good plan emerging for a 12-14V Win laptop powered direct from car. I'll leave you to puzzle how you might use/input if it's mounted in trunk.

Still want an inverter? OK, but if released from car-puter, and depending whether you wish to drive generally resistive loads, you may then be able to use a modified rather than pure sine wave unit.

I think that's about the limit of how I can help you, but I'll watch progress.
Best wishes
Ken

 

Mr, Sinatra, you are talking my world here. I do a lot of power stuff for trucks and what you are talking about is right in this ballpark. I think the first thing that you need to ask yourself is whether you want to power this inverter with the car off or only when the car is running. I ask this very specific question because this changes things drastically. The reason why is because imagine you have the inverter hooked up with what the car has currently and you are parked somewhere. After an hour or so of using the inverter, you plan to start the car, what you are most likely going to run into is a no-start condition because the battery has been drained down too much. As you can imagine, that is going to make for a bad day. This is where installing a dual battery setup with the second battery being a deep cycle battery that is isolated from the rest of the car except when the ignition is turned on. This will allow you to run the inverter for the maximum amount of time without having to have the car idle yet, when it is time to go, the car will start up with no issues and the isolator will control how much power the secondary battery will get (most isolators will ensure the primary battery gets all the power it needs and then whatever is left over can go to the secondary battery).

If this is sounding like what you are needing, then let me know. The wiring is not too difficult, but it isn't straight forward either.

You mention trying to run a laptop inside of your vehicle. Why not save yourself a lot of wiring and whatnot and go with something like a car PC. Something like Car PC Kit Intel Atom D2550 Mini ITX NVIDIA GeForce GT 610 D2550ITXS A E 4GB | eBay. This would make things very simple yet give you tons of options.

Like was mentioned, if you are going to use a laptop, the pure sine-wave inverter is about the only way to go. The others will work for things like a drill or whatnot, but electronics like a very clean waveform. On a side note, something to ponder is a rule of thumb I use is for every 10 watts of power from the inverter, you are looking at a 1 amp draw from the car. So, a 300 watt inverter will pull around 30 amps from the car. So, you will need to base your wiring accordingly. For 30 amps, I would recommend using 6 gauge wiring (this will be good for up to around 60-80 amps).

If you have any more questions, please let me know. I have worked with battery systems capable of powering a small town (yes, the battery was that big).

 

hi! thx for the post!


I think mainly to conserve space, I will not get a second battery. I also don't plan to run the inverter when the car is off, and actually I'd want to be able to switch the inverter off even when the car is running. I did get one, but i'm not sure i'll get it hooked up prior to my big road trip. here is an update on what I got:


a Wagan 400w Pure Sine Wave for $67, new on ebay. should arrive next week:


400 Watt Wagan EL2601 Elite 400W Pro Pure Sine Inverter Brand New | eBay


I also took to heart the idea of using DC natively, and found a great site with different "Carputers" that use 12v DC, also arrives next week, I got this one:


Fully Assembled Car PC with VoomPC-2 Enclosure, ASUS J1900I-C, M2-ATX-HV automotive power supply


I configured it with 4gb Ram, a DVD drive, and the 64gb SSD. $403


it includes this DC power adapter in the casing:


M2-ATX-HV (140w) Intelligent DC-DC Car PC Power Supply


and here is the manual:


http://resources.mini-box.com/online...-HV-manual.pdf


so that is intimidating to me! it has so many features and modes, and my mechanic doesn't have a lot of exp with this kind of hookup, and so I'm not sure what's possible, what I should ask for, what to hook up, etc...


however, what I do think I want, is for the computer to automatically turn on and boot after the ignition/engine cranks, and then to automatically power down gracefully when the ignition is killed. I get the impression this is possible, but its all beyond my understanding re: how to.


I would def be interested to hear any advice you have on setting this up!


thanks!

 

Mr, SInatra, what part of PA? I am about 3 hours south of you possibly in Southern Maryland. I would be willing to give it a shot. Otherwise, I think your best bet would be to find a stereo shop (NOT!!!! a place like Best Buy, etc) that specializes in car stereos. I am sure they could hook you up with what you are after for not too much money.

The on/off features like what you are after are all in the setup of the computer itself. The big thing will most likely be that you need to run both a constant (battery) power source to the unit and then also a switchable (ie, turns on when the car is turned on) power source. This will be how the computer knows when to turn on and when to shut itself off.

 

Great to see Mr Sinatra move towards his solution, especially with help offered by Chris [Thermo]. Others may be interested in another solution if the aim is just to run a carputer.

PENDO is the first manufacturer to take up Microsoft's offer of $0 cost to OEMs who install current Win 8.1 onto new tablets. Their new 8" tablet brings state of the art quad core cpu, 1280x800 IPS screen, great gobs of memory both internal and via microSD, and of course runs off 5V just like your phone . . . making in-car charging from a cig lighter a no brainer (although prob best if cig adapter is rated 2.1A rather than "el cheapo" 1A)

Oh . . . and it sells here nationwide via Target for less than AU$200. This tablet will happily store in glove box, and weighs only a fraction of any laptop. I'm getting one to replace my laptop's JLR V138 Mangoose PRO for SDD system, and will use 32Gb microSD cards for all my accumulated workshop manuals, wiring diagrams, and other data.

Best wishes,
Ken