Whelen recognition lights

[M20R]

Both of my recognition lights have burned out. I removed one of the lights and it said 14 volts. The parts manual shows a dropping resister, so this makes sense. But when I checked the voltage at the connector, it showed 24 volts. So the big question is do I order the new Whelen recognition lights in 14 volts or 24 volts?

[Greg Ellis]

@OSUAV8TER^^^^^^

[PT20J]

On 11/28/2023 at 8:53 AM, M20R said:

Both of my recognition lights have burned out. I removed one of the lights and it said 14 volts. The parts manual shows a dropping resister, so this makes sense. But when I checked the voltage at the connector, it showed 24 volts. So the big question is do I order the new Whelen recognition lights in 14 volts or 24 volts?

The dropping resistor is in series. with the light. When the light draws current the through the resistor, it will drop 12 volts. When you remove the light and measure the voltage, there is no current through the resistor and so it will not drop any voltage and you will read 24 volts.

Order the 12V recognition lights for your airplane.

Skip

EDIT: This should have said order 28V recognition lights. 

Edited December 5, 2023 by PT20J
Corrected voltage typo

[PeteMc]

I'd go with the LEDs.  But if for some reason you do not want to, my 14v recognition bulbs are about to come out when I put in the LEDs I got from @OSUAV8TER.  

 

[mhrivnak]

2 hours ago, PT20J said:

The dropping resistor is in series. with the light. When the light draws current the through the resistor, it will drop 12 volts. When you remove the light and measure the voltage, there is no current through the resistor and so it will not drop any voltage and you will read 24 volts.

Order the 12V recognition lights for your airplane.

Skip

UNLESS you get the LED replacement lights, in which case you still need the 24V/28V part: https://www.gallagheraviationllc.com/WAT-Mooney-28V-Recognition-Light_p_337.html

The short reason why is that since the LEDs don't draw much current, the resistor won't drop the voltage much.

[PT20J]

34 minutes ago, mhrivnak said:

UNLESS you get the LED replacement lights, in which case you still need the 24V/28V part: https://www.gallagheraviationllc.com/WAT-Mooney-28V-Recognition-Light_p_337.html

The short reason why is that since the LEDs don't draw much current, the resistor won't drop the voltage much.

You're correct. My bad. I meant 28V but typed 12V instead.

[Marc_B]

The original recog lights were a 14 volt halogen. So 28v aircraft had 7.5 ohm resistor wired and since the halogens drew around 2amps this acted as an appropriate step down. 14v aircraft didn’t need the resistor but used the same recog light. However WAT LED recogs draw 0.085 amps (28V version) / 0.17 amps (14V version), so voltage step down from resistor is minimal. Hence, WAT made14v and 28v units that you match to your aircraft voltage. And don’t worry about removing the resistor; also the LED wires have no polarity so it was pretty much a cut and splice. 

[Pinecone]

FYI, the light lenses are now around $373 each.  So the LEDs make even more sense.

[OSUAV8TER]

The LED recognition lights are 15% off through Friday, December 8th. You need to select the voltage for the LED recognition lights that corresponds with your ship electrical power. I know that for the 28V Mooneys there is a resistor that drops the power but you still need the 28V lamps. Links are below. 

https://www.gallagheraviationllc.com/WAT-Mooney-28V-Recognition-Light_p_337.html <-- 28V Mooney LED Recognition Lights

https://www.gallagheraviationllc.com/WAT-Mooney-14V-Recognition-Light_p_140.html <--14V Mooney LED Recognition Lights

[Electro]

On 11/28/2023 at 10:08 AM, PT20J said:

The dropping resistor is in series. with the light. When the light draws current the through the resistor, it will drop 12 volts. When you remove the light and measure the voltage, there is no current through the resistor and so it will not drop any voltage and you will read 24 volts.

Order the 12V recognition lights for your airplane.

Skip

I just installed the 24V Whelen LEDs on my 24V system connected to the existing dropping resistor. They work great. As pointed out, the no-load voltage will read ~24V. However, the Whelen LEDs draw far less current than the original halogens. Therefore, the voltage will be much closer to 24V when connected to the LED replacements with only a small voltage drop. Alternatively, you may bypass the resistor but either way use the 24V specification not 12V.

[Jetpilot86]

Looking forward to getting mine installed tomorrow!