resistors.... - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Adam Kindness · 1st July 2008, 12:45 PM

i have an inlet temp display that works on 5v. I have found a supply that puts out 5v when the key is turned to ACC, but goes upto 6.1v when the car is running.

What resistor will be best to fit inline to lower this 6.1v to <5v

ru' · 1st July 2008, 03:33 PM

I wouldn't use whatever it is you've found. Best thing would be to find some in-car gadget with a ciggy lighter type power supply putting out 5v, and use the power supply.

Anything which can be used on USB generally uses 5V, so hacking the power adaptor is easy.

Using a resistor depends on the current the device draws, so without that info a value can't be suggested.

ru' · 1st July 2008, 05:57 PM

In fact, this may help too:

AutoSpeed - Cheap and Easy 5V Supply

freakazoid3 · 2nd July 2008, 12:31 AM

Little off topic here, but does someone know where to get the inlet temp displays from? Cheapish...

ITSt · 2nd July 2008, 09:07 AM

Hi Adam,

Maplin have a few things that would help you:

Maplin > In-Car Power Adaptors

I've not had time to look through them but there must be something in the above that will give you 5V inside the car from 12V.

1st July 2008, 12:45 PM	#1 (permalink)
Adam Kindness GTR Register Member Join Date: Jun 2002 Location: Aberdeen Posts: 2,210	resistors.... i have an inlet temp display that works on 5v. I have found a supply that puts out 5v when the key is turned to ACC, but goes upto 6.1v when the car is running. What resistor will be best to fit inline to lower this 6.1v to <5v

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1st July 2008, 03:33 PM	#2 (permalink)
ru' New Users Join Date: Feb 2007 Location: Black R33 GTR V-Spec Posts: 1,878	I wouldn't use whatever it is you've found. Best thing would be to find some in-car gadget with a ciggy lighter type power supply putting out 5v, and use the power supply. Anything which can be used on USB generally uses 5V, so hacking the power adaptor is easy. Using a resistor depends on the current the device draws, so without that info a value can't be suggested.

1st July 2008, 05:57 PM	#3 (permalink)
ru' New Users Join Date: Feb 2007 Location: Black R33 GTR V-Spec Posts: 1,878	In fact, this may help too: AutoSpeed - Cheap and Easy 5V Supply

2nd July 2008, 12:31 AM	#4 (permalink)
freakazoid3 GTR Register Member Join Date: Jan 2008 Location: Sunny Belgium...right :) Posts: 704	Little off topic here, but does someone know where to get the inlet temp displays from? Cheapish...

2nd July 2008, 09:07 AM	#5 (permalink)
ITSt GTROC Member Join Date: Apr 2006 Location: Scotland Posts: 699	Hi Adam, Maplin have a few things that would help you: Maplin > In-Car Power Adaptors I've not had time to look through them but there must be something in the above that will give you 5V inside the car from 12V.