how to make parklights/tails fade on/off
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Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=100178
Printed Date: May 21, 2024 at 2:25 AM
Topic: how to make parklights/tails fade on/off
Posted By: gpchris
Subject: how to make parklights/tails fade on/off
Date Posted: December 18, 2007 at 12:16 PM
Is there anyway to make my amber parklights and taillights fade on? I'd like the fade to only last about a second. IS there anyway to do it? And I know my brake lights cant fade, its just not safe but I have an idea to make the tails only fade on with headlights, not the brake lights. Is there like a relay or somthing that will allow them to fade??
Replies:
Posted By: KPierson
Date Posted: December 31, 2007 at 12:38 AM
You will either need a PWM circuit or an analog voltage circuit. To my knowledge there arn't any fade relays.
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Kevin Pierson
Posted By: tedmond
Date Posted: January 01, 2008 at 4:58 PM
i think you could wire in a resistor somehow to let the charge slowly dissapate, but im sure that resistor would sure get very hot.
Posted By: i am an idiot
Date Posted: January 01, 2008 at 5:47 PM
What you are trying to do can be done with a resistor and a capacitor. The capacitor paralleled across the bulb and the resistor in series with the wire that feeds them. As stated above the resistor will probably get hot. I will try a few combinations at work tomorrow to see what I can do to get a 1 second fade. The resistor will charge the cap slowly giving it a fade on condition. Then when the power is removed from the wire the cap will keep the bulb illuminated untill it discharges. Thus causing the fade off. What kind of a vehicle are we dealing with?
Posted By: KPierson
Date Posted: January 01, 2008 at 10:48 PM
Fade off isn't a big deal, it is the fade on that is tricky. There was a big thread on this many months ago talking about dome lights. There were circuits posted that would dim off the dome light and the person got that to work. I posted a schematic that I thought would fade on and they could not get that part to work. ------------- Kevin Pierson
Posted By: KPierson
Date Posted: January 01, 2008 at 10:50 PM
Also, what kind of car is this? Is it going to be used on the streets? You may run in to legal issues with this, not too sure. I know the DOT is pretty strict on vehicle lighting.
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Kevin Pierson
Posted By: tedmond
Date Posted: January 02, 2008 at 9:40 AM
that is true, laws are very strict when it comes to vehicle lighting. ie no underglow, strobes and many more that affect other drivers. well as i am an idiot mentioned, there was a thread about this longg ago and it was sure as hell long. using the resistor to charge a cap is no biggie, but im not sure where you would find a resistor that doesnt get hot. Are you planning to just turn on the lights once? or multiple times?
Posted By: gus1
Date Posted: January 06, 2008 at 7:49 PM
One could use an SCR to ramp up and down the voltage. A 1 sec fade time would be difficult to implement in a flashing situation, however, to make them fade on at initial turn on, then fade out when turning off shouldn't be too bad to do at all.
There should be a circuit available on a DIY electronics site that would outline the parts values necessary to both build the circuit to turn the SCR on and off, and to set the time value of the fade. One could also use some form of aftermarket lighting controller (say for undercar), provided that it has the current capability (not knowing the vehicle, I would say something in the neighborhood of 10 to 15A DC at the most for pretty much anything on the road passenger vehicle-wise)
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Wherever I go, that is where I end up......
Posted By: gpchris
Date Posted: January 16, 2008 at 11:17 PM
does anybody want to make this for me? I'll pay for it and shipping. I can give you all the information you need. PLEASE let me know if anyone can do this for me!
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