Flashing car headlights @ overload

Thread Starter

Vytas Klyvis

Joined Dec 5, 2016
75
Hi,

I have a project where I want to be able to flash regular h4 car lights extremely brightly for about 100ms. The lights will already be operating at this point at 12v 40watts. I dont seem to find any information on how long I would be able to operate this light on a high power and how much power it could handle.
The second part of this project would be on how to get the power to the lights. Id figure I have a few options:
- Generating a higher voltage and then quickly toggle to that voltage using a relay
- Putting a transformer in series with the light and quickly pulsing the secondary
- Putting a transformer in parallel and preventing the voltage from reaching the battery using a diode or something

I hope I got it all across. I will try to upload some schematics of what I am trying. Thank you!
 

Dodgydave

Joined Jun 22, 2012
11,395
If the lights are 12V rated, then theres no point in generating high voltage!!

Are you working with DC or AC,?

All you need is a Solid state relay, or Triac and a timer like a 555 chip, to give your 100mS pulse to the lights.
 

Reloadron

Joined Jan 15, 2015
7,887
If the lights are 12V rated, then theres no point in generating high voltage!!

Are you working with DC or AC,?

All you need is a Solid state relay, or Triac and a timer like a 555 chip, to give your 100mS pulse to the lights.
With that in mind you can't make the lights any brighter than they were designed for unless of course you wish to toast them. If you just want to flash the lights at some given pulse rate, similar to what police cars do, then a simple timer circuit like the 555 mentioned and a DC SSR (Solid State Relay) as mentioned will work just fine. Additionally an incasdecent bulb can only be pulsed do quick before the change won't be visible to the human eye.

Ron
 

Thread Starter

Vytas Klyvis

Joined Dec 5, 2016
75
What I am understanding is that the lights will not be able to support the higher power for even a short brief? If not, would say a heating element be able to do it?

The problem is not making the lights blink. I have an arduino and 555 timers lying arou d for that purpose. I was wondering if and maybe how this higher power could be delivered.
Thank you for the quick responses!
 

Thread Starter

Vytas Klyvis

Joined Dec 5, 2016
75
What is the purpose of doing this? What country are you in? Most locales should have regulations regarding how bright headlights can be.
I wanted to make a high power, low frequency portable flasher using components that I have readily available (low cost). But now I have seen the chart for the lifetime of the lights during overload. This might not be the brightest idea.
 

MaxHeadRoom

Joined Jul 18, 2013
30,654
H4 is a headlight Don't you have a high beam momentary flash switch like most modern cars have had for a few decades now? And use that?
Max.
 

Thread Starter

Vytas Klyvis

Joined Dec 5, 2016
75
Could you just flash the high beams in addition to the low beams?

Edited to say they probably wouldn't even light up in 100ms.
Thats why I thought I would have them already running before flashing at a higher power.

H4 is a headlight Don't you have a high beam momentary flash switch like most modern cars have had for a few decades now? And use that?
Max.
Should have thought of the high beam aswell.
 
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