New prject for TV and need help - Page 2

ashrafkh · #11 04-07-2009, 05:42 AM

Quote:

Originally Posted by KiwiJochen

Relay is a must, because the TV tuner uses a input that is connected to ground to activate the reverse cam.
So the relay performs the function of activating the RevCam input.

ya i noticed the same from other threads but the seller i bought the RCA cable from said that i need only to connect into PIN 17 on the blue connector to get the ground.. so since PIN 17 provides ground why would i need a relay unless its a power stablity issue

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KiwiJochen · #12 04-07-2009, 12:42 PM

Quote:

Originally Posted by ashrafkh

ya i noticed the same from other threads but the seller i bought the RCA cable from said that i need only to connect into PIN 17 on the blue connector to get the ground.. so since PIN 17 provides ground why would i need a relay unless its a power stablity issue

To activate ReverseCam, pin17 needs to be connected to ground.

You can connect it to ground using various methods such as a manual switch.

If you want the reverse camera to come on automatically when selecting reverse gear, you have to switch the pin to ground through some circuit in the car.

The simplest and most convenient circuit to use is the reverse lamps. However, these have 12V when on, ie: they do not switch to ground.

How to change a 12V-when-on to a ground-when-on switching signal?

You could use a circuit built with opto-couplers, transistors, FETs, even glowing valves if you want.

But the easiest, simplest method is a relay.

ashrafkh · #13 04-07-2009, 02:03 PM

Quote:

Originally Posted by KiwiJochen

To activate ReverseCam, pin17 needs to be connected to ground.

You can connect it to ground using various methods such as a manual switch.

If you want the reverse camera to come on automatically when selecting reverse gear, you have to switch the pin to ground through some circuit in the car.

The simplest and most convenient circuit to use is the reverse lamps. However, these have 12V when on, ie: they do not switch to ground.

How to change a 12V-when-on to a ground-when-on switching signal?

You could use a circuit built with opto-couplers, transistors, FETs, even glowing valves if you want.

But the easiest, simplest method is a relay.

MAN!!!!!!! you are great adviser

do you have the diagram ?

ashrafkh · #14 04-07-2009, 04:38 PM

this thread says that i have to use 2 relays for aftermarket cams! do you agree?
http://www.xoutpost.com/x5-e53-forum/...era-issue.html

KiwiJochen · #15 04-07-2009, 04:51 PM

Quote:

Originally Posted by ashrafkh

this thread says that i have to use 2 relays for aftermarket cams! do you agree?
http://www.xoutpost.com/x5-e53-forum/...era-issue.html

You can power the camera permenently, or only when in reverse - up to you.

ashrafkh · #16 04-08-2009, 03:29 AM

Quote:

Originally Posted by KiwiJochen

You can power the camera permenently, or only when in reverse - up to you.

yes yes i know that, but am consulting you about the fact that using one relay will case noise so its recommemnded to use 2 relays

trapdoor · #17 04-08-2009, 04:29 AM

Quote:

Originally Posted by ashrafkh

yes yes i know that, but am consulting you about the fact that using one relay will case noise so its recommemnded to use 2 relays

The problem with 'supply noise' on the camera supply input COULD cause the issues that are described. It would very much depend on the camera module, how well it's made etc etc... the idea of the 2nd relay is that it will provide a clean switched +ve supply to the camera that doesn't also have the reversing light bulbs/LEDs on the same circuit.

It could be done with a single relay that has two sets of changeover/switching contacts so the coil is energised from the reversing light cct, one set of contacts is used to ground pin 17, the other set of contacts is used to switch 12v to the camera supply.

Personally, I'd go for a single relay with the two sets of contacts if you can source one.