Cockpit light

I just got around to adding the lighting kit to my Classic RV-12 (serial #284) a few weeks ago, and installed the cockpit light yesterday. I have heard that it isn't particularly effective, but having bought it I thought I might as well install it.

Because I didn't buy the lighting kit 8 or 9 years ago when I was building, so I don't have a Chapter 40 from that era. The current chapter 40 references YLW/PRP and YEL/GRN wires, which my plane does not have. What it does have is a pair of white wires of the appropriate length and position to reach up through the rollbar to the cockpit light position. I checked them with a multimeter and they responded to the Nav/Strobe switch.

That leads me to believe that they are the wires intended to power the cockpit light, but they only indicated 5V on the meter.

The David Hoffman Mod-1 lights are specified on their web site thusly:

MOD-1 COCKPIT LIGHTS

-SPECIFICATION-

VOLTS AMPS WATTS
14 0.012 0.168

Would it make sense to track down the source of the B-179 wire (going from memory that the B-179 was the POS wire) and shift it over to a spot where it can get 12V?

I am assuming more voltage means more light from an LED, but I'm not anywhere near sure that that is the case.

I didn't build my plane but its #212 and has that light installed.

5v or a little less should be fine for Red LED lights.

Other option is take a variable voltage power supply to your cockpit/flightdeck light and see what it really needs? Does it have voltage reduction circuitry built in to it from 12v to what the LED lamp really needs? Or check the specs for required voltage on your strobe/ nav lights also, if they are on the same circuit, in your plans.

The dimmer controled output for lighting is a pwm circuit (pulsed DC).
You cannot accurately measure the voltage of a pwm output with a typical meter because it will indicate the rms value.

The purpose of that light is not to act as cockpit lighting for reading maps, etc. It is to meet a lighting requirements for being able to read switch labels etc., on the panel.

All LED lights need a series resistor to limit the current. LED lights that are
advertised to to work on 12 volts have an internal resistor that you might not
be able to see. If you want the LED to operate at full brightness all of the time,
then you could connect it to 12 volts. But if you want to dim the light, then use
the existing wires intended for the light.

a little off thread but.....i am a day vfr pilot. i have no use to light the gauges. i do want to light the cockpit.i have the conventional wiring but instead of the van's light on the rollbar i mounted a usb port just forward of the rear bulkhead. there are a million ''gooseneck'' usb reading lights out there for $10. i do light the whole cockpit with my set up.

bobnoffs said:

a little off thread but.....i am a day vfr pilot. i have no use to light the gauges. i do want to light the cockpit.i have the conventional wiring but instead of the van's light on the rollbar i mounted a usb port just forward of the rear bulkhead. there are a million ''gooseneck'' usb reading lights out there for $10. i do light the whole cockpit with my set up.

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Correct me if I am wrong... my plane was certified airworthy in 2012, but you also need a rear dome directional strobe tail light to fly a RV-12 at night, which I don't have.

NinerBikes said:

Correct me if I am wrong... my plane was certified airworthy in 2012, but you also need a rear dome directional strobe tail light to fly a RV-12 at night, which I don't have.

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Research the night requirements for aircraft. It’s the same whether it is certified experimental SLSA…
The short version is that you have to have anti-collision lighting that meets visibility requirement 360° around the airplane and If I remember correctly 30° above and below the horizontal plane of the aircraft. The wingtip strobes installation on most aircraft meet that requirement As long as they aren’t inside of wingtip enclosures that prevents them from being seen from behind.

rvbuilder2002 said:

The purpose of that light is not to act as cockpit lighting for reading maps, etc. It is to meet a lighting requirements for being able to read switch labels etc., on the panel.

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Ah, perfect. That’s really all I need from it. I’ve got three red flashlights sprinkled around the cockpit for more targeted usage.