Bright Six

[Guest mark kingston]

i have built a new dashboard using separate instruments and using the new product lanched called a bright six which is a oil, handbrake, turn indicator, charge light and high beam indicator all in one small smart unit. it uses bright leds.

I wired in the unit as per instruction and it all worked fine .

then after having the lights on high beam for about 10 seconds the blue led went out never to work again..

I phoned my supplier and got sent a replacement unit which i wired in tonight.

once again all worked fine untill high beam was left on and again the blue led goes south???

has anyone else tried this product??

i guess the is either a faulty batch or the design is flawed.

your feed back is most welcome..

I am not sure what to do now as the whole dash was built around using this unit and i have even cnc machined up a alluminium bezel to fit it so it matched the telemetrix instruments i have fitted.

regards

mark kingston

[Dave R]

could maybe be a relay on you main beam blowing the led with the back emf when it de-energises

or as you say its a crap design/faulty

does the blue led look over bright to you compared to the other led's?

 

 

Dave

[Guest Guy]

The back EMF spike sounds the most probable,

 

How is your main beam relay wired?

 

Does the LED take it's power from the low current side of the relay or the hi current side that goes to the headlamps?

 

Does your main beam switch act on the 0V or the +12V side of the relay?

[Guest Andy Rathbone]

it sounds like there is no resistor on the led and its going across the supply, the back emf pulse wouldnt effect the led its a one way valve, and the coil in the realy is probably not big enough to generate a damaging emf pulse, if the led is on the bulb side of the relay the amperss will be much too high for the led they can. leds can only take about 50milli Amps tops before they expire. for 12v on led you need a 1k resistor down to about 330R min, good luck

[Guest mark kingston]

Hi it takes its feed from the low side of the relay.

I spoke to Lighting looms the manufacture today and they say that it is the back emf spike from the relay causing the problem and that if i return them the unit they will supply a modified one to use with relays.

They are most helpfull and it appears they have now changed it and the instructions.

many thanks for your help guys, i will let you know how i get on with the replacement.

[Guest Guy]

As it's a module produced by a company I don't think they will be expecting you to fit your own dropper resistors, it's most likely to have it's own internal one.

 

A blue hyper bright LED can only take about 5V reverse voltage before it goes PHUT, if you are running it from the + side of a coil and then switch the + supply to the coil off the inductance will cause the + side (and so the anode of the LED) to go a long way below the 0V rail, this will POP the LED.

 

Most people put a reverse biased protection diode in series with an LED to protect it.

[Guest Charles B]

If your worried about back emf spikes in the future, you can get relays with diodes fitted across the coils (or do it yourself)

[Dave R]

would have thought uncle hernry would have fitted diodes as standard to have protected the donor ?

but obviosly not!

:boohoo:

[IanS]

Uncle Henry fitted an normal incandesant bulb as high beam indicator. They dont care which polarity they are connected and so will absorb the back EMF with no ill effects. So Uncle Henry has saved the price of a diode times Xmillion sierras produced.

[Dave R]

yes but there was a whole host of other electronics in the donor