As part of a project I want to power on, when the inside light goes on in my van. Simple I'll add a relay to the back of the light easy right? No. The light sort of fades on, as a result the relay comes on with a buzz instead of a click.
So my questions are.
1 Using it like this will it damage the relay and or arduino board.
2 any suggestions on how to make the relay work correctly.
Thanks in advance.
Paul
Relay buzz makes me think that there is not enough power for the relay coil.
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html .
Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Thanks.. Tom.....
The van has a 12v with the ground connected to the van bodywork.
The light has 12v constant supply and switched on the ground side.
The switch has three positions always on always off and on when the door is opened.
The light fades on when the door is a opened has a delay then fades off again if the door is closed.
I have a relay with its coil connected between the constant 12v and the switched ground that works with the door.
Hi,
What model car are you using it in?
What is the relay, link to data/specs please?
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Did the original interior light fade?
If so then using a relay will as you have found not do a good job with the LED driver.
Tom..
Perhaps you have inadvertantly connected the relay in series with the lamp?
Maybe there is a maximum current limit on the lamp dimmer, and this is not quite enough to energise the relay. It follows that the door switch may not directly earth the downstream side of the lamp (or there would't be a dimming function)?
Maybe the door switch takes an ECU pin to earth, and the ECU then controls the dimming function? The danger here is that the ECU may be damaged by trying to drive your relay current.
A little investigation may be necessary before you can make progress on this.
I also suggest that, to keep the interest of those experienced Arduino-ers, you include a brief description of what you want to achieve with your project...remember they do this for free, so otherwise what's in it for them?
GM
The "fading" is done by PWM which is usually (as it is on most Arduinox by default) an audible frequency, so the relay is acting as a sounder.
It is probably not really good for the relay.
Explain what your project is, and why it needs to function only when the light is on. Also why you cannot connect it to the door switch instead of the light.
There will be more appropriate ways of switching it, possibly just putting it in sleep mode when not required, than using a relay.
It's an alarm project for a UK mk7 transit van.
I want to link it to my home alarm.
As the light comes on whenever any door is opened, it seems an obvious choice rather than installing new switches to all the doors.
I tried connecting the coil of the relay between 12v and ground with a transistor acting as a switch. Thinking the transistor would only conduct when it's base received enough power. It did work, but with the same buzz.
The relay is a small generic automation 12v relay.
I'll try to see if I can upload a circuit diagram.
Hi,
Does the original interior light fade up and down?
If it does then that is why your relay is chattering, the fading of the light is done by PWM control.
Tom...
OK, so the point is that you already have the switches.
The switches are connected to a controller somewhere in the vehicle which contains the logic to fade the light (as I said, using PWM). So that controller has an input from the switches, and an output to the light.
You have been connecting to the latter, at the lamp. You need to trace the wiring from the door switch (any switch) to the controller and intercept that connection, not the lamp connection. You should be able to figure out what the specific colour code for the switch connection is and trace it around the vehicle to the most convenient point for your project. The controller is most likely under the dashboard and may be part of some other vehicle control electronics.
There is some possibility it may be part of a CANbus system, which would be a different, but not insurmountable problem.
a bit of confusion here. since you would hard wire the van to the relay to the home alarm....
something seems amiss.
first off, a relay is probably the wrong choice.
what does the home alarm look for ?
would my assumption that the lights going on is an input to the home alarm ?
if that is the case, then any voltage divider, opto-isolator, etc would be able to sense the condition and then pass a simple signal.
this project seems to be screaming for a simple block diagram schematic with arrows
I would HIGHLY recommend you offer more of a generic overview of what you want and let us offer some simple solutions.
it would make this go much faster and might be much simpler in the end. DO state if there is any wireless bits needed.
I'm using the door contact sensor I made for the doors. they link with rf433 and use a reed switch to activate.
I'm adapting the design to use a relay instead of the reed switch.
The alarm and door sensors I have working.
But having had some uninvited visitors in my van I was looking for a quick way to link it in.