livers

livers

Well-Known Member
Got a level gcse in physics, forces reckoned I could wire up aircraft bomb and safety systems, including nucular, but being old and senile I now doubt my knowledge.
Want to hard wire sat-nav into car, memory suggests car=12V sat-nav=s4.5V so 9volt bulb in series should work?
 
livers said:
Got a level gcse in physics, forces reckoned I could wire up aircraft bomb and safety systems, including nucular, but being old and senile I now doubt my knowledge.
Want to hard wire sat-nav into car, memory suggests car=12V sat-nav=s4.5V so 9volt bulb in series should work?
Click to expand...


NOOOOOOooooooooooooo.....


Well, yes, kinda, in theory, but, then if the bulb blows... :eek:

Just buy a mini dc:dc converter thingy - or - even better, open up the sat nav cigarette lighter and remove the one from in there, put it in a little box.
 
is it one that will charge from a USB?? if so, get a USB cable, and pay £2 for a 12V-USB stabiliser (ie one of those plug in USB PSU, then take it out of its case.

Don't try and do it with a lamp or resistor, don't forget a car voltage is form 12.6-14.4, quite a big % change that yer satnav wont like if you use a passive device.

I bought a 3A USB PSU for about £5 from the bay, and have it connected to a USB hub to power the satnav/phones/tablet etc.
 
If you want less hassle to remove it later buy a usb plug in thing and a lighter socket too for a couple of quid then you can wire in the socket and hide it behind somewhere with the plug in, safest, easiest way in my opinion.
 
Oh this is a bit more expensive but would be less hassle, didn't know they made them like this

powerlink_usb_charger_socket.jpg
 


I have one fitted perm. where the clock was in my Freelander......usb runs down thru the dash to the 'cubby hole' near the fuses where i have another cig lighter do da!!!!!

Lovely & neat ;)
 
On my Disco 2 I've installed one of those accessory socket devices with two cigarette lighter type sockets and two USB power sockets behind the fuse panel door under the steering wheel. I just stuck the device onto the inside of the door with "Sellotape Sticky Fixers"; little double sided sticky foam pads.

I then ran a USB power lead up through a small gap between the door edge and the dashboard to feed my smartphone on the dash; I use it as an mp3 player. The only trouble I came across was "alternator whine" so I got the Sticky fixers out again and installed a cheap alternator whine filter in the lead to the accessory socket. That's stuck on the inside of the door too.
 
The resistance of a filament lamp is less when it is cold, and increases as it reaches operating temperature and glows, so you may find the current flow on switch on will be too high, and the lamp will not drop the 9 volts you expect. The short period before the lamp lights may be enough to kill the other item in the circuit.
 
Sheffield said:
The resistance of a filament lamp is less when it is cold, and increases as it reaches operating temperature and glows, so you may find the current flow on switch on will be too high, and the lamp will not drop the 9 volts you expect. The short period before the lamp lights may be enough to kill the other item in the circuit.
Click to expand...
Sh1t this black magik stuff is complicated:confused: guess I will have to take all those 1.25V Ni-Mh accu's out of everything and put proper 1.5V batterys back in:(
 
You must log in or register to reply here.