How can I add a capacitor to my car's headlights, causing a 5 second fade effect when turned off?

Question

I have a 2005 Hyundai Elantra (GT). I would like to add a capacitor to the headlamps that will cause a fade effect when turning off my lights. What is the best capacitor placement, type and circuit for this idea?

guru · Accepted Answer

Something in the range of 5 to 20 Farads
0.1F would cost about $200

Hope this properly answers your question


Guru

jpopelish · Answer

A capacitor is not a practical way to do this.  Lamp dimming is usually done with pulse switching, where the supply is turned on and off very rapidly (compared to the thermal time constant of the filament) and the ratio of on and off time is varied to shift the effective average voltage.  But at the current level involved in headlamps, and he fact that they are critical safety equipment, this is not a beginner's project.  Sorry.

-- 
Regards,

John Popelish

? · Answer

A capacitor wont do it as it can hold enough reserve for something that large.
A capacitor that size is very expensive like $500.00
Only thing i can suggest is that you use a time delay relay that will switch them of say after you get to your house. eg 10 seconds, 15 seconds.
It would need to be wired into the original relays for the lighting system.

RBP · Answer

You can't get a capacitor big enough to do that.

How can I add a capacitor to my car's headlights, causing a 5 second fade effect when turned off?

4 Answers