NOOB needs help

[pootler]

Hi - new to the forums.

I have been building a car pc for the best part of two years on and off

I know car pc's have dropped off the radar- but its what I have to work with.

This is not professional, and I am using the bare minimum hardware that I have , and that I can get?

It consists of a Windows 10 Tablet which is placed in front of the main fascia.
It is not in the fascia and I have done no fancy work to make it fit in - it looks fine.
I have a box that fools my honda into thinking that the audio output of the tablet is part of the multi cd player, so it ouputs fine.
All of the accessories are usb and housed in a separate box in the glove compartment.
There are five usb devices , in a powered usb 3 hub.
The tablet has a full size usb port.
This enables me to receive DAB radio, external GPS, Bluetooth receiver, windows mce remote. and external usb microphone.
Although I have a shiny windows tablet in front of me, I have NO intention of touching it whilst driving - the system is set up so I can input 95% of info using a cheap chinese steering wheel remote ( MCE ), for switching functions, and I also have limited voice control.
Not forgetting hands free.
The hub receives power from a 12v to 5v convertor ( 5V 3A ) via the acc cigarette lighter fuse
The tablet receives power direct from fusebox ( 12V 3A) via the acc fuse.
This is done with add -a -fuses, so additional fuses are there for the devices.
Both provide power when ignition is off for listening.

o.k, so everything works, but I have one major frustration - you may all laugh now

The install works fine when in 'acc'' mode, so I can listen without the car running.
But , when I turn the engine on, the Honda disconnects all power to everything :-(, so the tablet survives ( it switches to battery power for the brief moment it loses it from the car), but my accessories disconnect , and with the wonder of Windows ( ! ), they dont' connect properly after that.
The unit needs to be restarted to begin working correctly again ;-(.

Now , as explained , when it comes to electrical stuff, I am total NOOB, but can follow clear instructions.

Does anybody have a solution that I may be able to follow to prevent this?
I cannot have any permanent feed to the usb accessories, as this would drain the battery fairly quickly ( the hub is drawing around 2A )

Many Thanks in advance

pootler

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[sounds_explicit]

So the hub is losing power once engine is started? And the hub is the brains for all your usb stuff? This kind of sounds like a acc/ignition issue almost. I would try to re direct power source from the cig lighter to the ignition and fuse it.

 

[sounds_explicit]

To my understanding.. when you switch from acc to ignition while starting the car there is a drop in voltage or kills the voltage completely. That may be your problem. Is that once your car is in acc mode everything is fine.. but when you turn the tumbler over it loses contact inside untill it reaches the point jn contact that actually starts the car. That very swift time frame between acc and actually starting the car might be the issue. If you understand what saying. I've never had any luck wiring stuff into acc or cig lighter fuses . These new cars these days do weird things with the electrical. I would most def get a wiring schematic of your radio and find the ignition wire. Tap into that and fuse it before your hub and see if that fixes your problem

 

[pootler]

To my understanding.. when you switch from acc to ignition while starting the car there is a drop in voltage or kills the voltage completely. That may be your problem. Is that once your car is in acc mode everything is fine.. but when you turn the tumbler over it loses contact inside untill it reaches the point jn contact that actually starts the car. That very swift time frame between acc and actually starting the car might be the issue. If you understand what saying. I've never had any luck wiring stuff into acc or cig lighter fuses . These new cars these days do weird things with the electrical. I would most def get a wiring schematic of your radio and find the ignition wire. Tap into that and fuse it before your hub and see if that fixes your problem

HI,

Thanks for the reply,

Yes - I think you pretty much get it.

So - I presume the ignition wire is something that would be found at the ignition switch

This is not a permanent feed is it? - as explained, the hub drains too many amps for a permanent feed.

Sorry for the noobishness of my reply

Pootler

 

[sounds_explicit]

It is a direct feed but. It only provides power when the ignition is on. There is also a constant. 12 volt wire as well. That will def drain your hub as it's a constant power.

The ignition wire yes runs from that area
But people usually tap into it via the wire harness that is directly attached to your radio. You can run a dedicated run from that wire add a toggle switch and then run that to your hub . Either way the hub shouldn't turn on unless you stop the engine and or flip the toggle switch. But it shouldn't bee needed if you tap into the ignition wire.

 

[sounds_explicit]

If that seems too much, you can grab toggle switch . Run the power source from your battery to the switch then run that to your hub. Yoy need to figure out how any amps all of your usb stuff is using as well. In order to fuse the switch with the rivht fuse size usually as close to the battery as possible. They sell in line fuses switches stuff like that at local car parts store.

 

[1aespinoza 10+ year member]

Many Thanks in advance

This may be what you are looking for. Instructions included.

Electronics, Cars, Fashion, Collectibles & More | eBay

Buy & sell electronics, cars, clothes, collectibles & more on eBay, the world's online marketplace. Top brands, low prices & free shipping on many items.

rover.ebay.com

 

[sounds_explicit]

This may be what you are looking for. Instructions included.

http://[URL]https://rover.ebay.com/...0001&campid=5335951755&icep_item=320634780252

[/URL]

That will work as well.

 

[pootler]

That will work as well.

HI,

Wow - people weren't joking when they said this was a useful form!

Thanks all - will look into the options and let you know

pootler

 

[pootler]

O.K,

Had a look at these things - and played with a few.

I don't think the off the shelf version suggested is compatible with my requirements, as the timer starts when the coil is energised.

I think it is meant for something like delaying powerful headlights ( or other current hungry devices )from coming on immediately, during engine cranking.

I need a relay that will be permanently energised, and then changes contacts ( for a set time ) when de-energised ( that is , when the 12V acc feed loses voltage.) It then switches to a constant 12V , eventually returning to the original contact state after the timer runs down.

I believe it is a NCTO or NCTC relay.

I am trying to see if there is a module available.

Will post any news.

Cheers

pootler

 

[1aespinoza 10+ year member]

I am trying to see if there is a module available.

So that one worked backwards. The one I used was an off delay for interior lights. This one has what you are seeking.

Electronics, Cars, Fashion, Collectibles & More | eBay

Buy & sell electronics, cars, clothes, collectibles & more on eBay, the world's online marketplace. Top brands, low prices & free shipping on many items.

rover.ebay.com

 

[LsGuy]

What about a small inline cap? Something that stores a little power and can feed the accessories for a second until power kicks back in.

 

[pootler]

What about a small inline cap? Something that stores a little power and can feed the accessories for a second until power kicks back in.

I think the sort of cap required to sustain 12V @ 2/3A for 2/3 secs would be big and expensive?

Cheers

Pootler

 

[pootler]

So that one worked backwards. The one I used was an off delay for interior lights. This one has what you are seeking.

Electronics, Cars, Fashion, Collectibles & More | eBay

Buy & sell electronics, cars, clothes, collectibles & more on eBay, the world's online marketplace. Top brands, low prices & free shipping on many items.

rover.ebay.com

I am in UK.

Inc postage that will cost me almost half the price of my entire install?

Will try to find something similar in UK.

Cheers

pottler