Hey guys... I am working on a custom sign using leds. The problem i have is, full brightness to be seen during the day will be blinding at night. I was thinking of using a switching relay for power and having a resistor on one leg, triggered by an exterior light circuit to power the signs. What i have been looking into, is using a transistor setup to try for a solid state system that i can keep out of the weather.

Any ideas? The load would be quite small 2-3 amps at 12-14v with a 12-14v trigger.

 

I disagree with the idea that you are going to "improve" a system that only uses one relay and one resistor by building a transistor rig. Just use a store-bought eyeball to fire a 120 VAC relay coil and have that one relay connect or disconnect a resistor.

 

Why do I suspect this custom "sign" lives in the taillight of your vehicle?

http://forum.allaboutcircuits.com/showthread.php?t=74026

Tisk tisk.

 

Hello,

This is the second thread we have to close on a vehicle related subject:
Transistor or relay

Next try will result in a ban.

Bertus