5702KA question
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Alaric Darconville
Flashlight Enthusiast
Assuming 302/19lm, and (major/minor) at 12.8V and 1200/1500hrs (major/minor) at 14.0V , the math says at 13.3V, the major filament will put out about 310lm and last 3000hrs. At 15.3V, assuming it survives, it'll put out 499 lumens and last 378hrs. It almost surely won't unless slowly ramped to 15.3V and there's no vibration.
This is based on output going up to the power of 3.4 with changes in voltage, and life changing to the power of -13 with changes in voltage. (This particular relationship is stated all over the automotive section.)
Why ever would you want to feed a bulb like this 15.3V?
Edit: to say Thank you!
Mainly playing around with different options for a DRL. The bulb in question is designed for the high voltage and I am considering the suitability of using it in a "normal" voltage situation compared to say a 3157A or 3457A.
Concerning the high voltage, in 2005 Daniel Stern stated, "The last two bulbs on the list exist because of GM's stupidity. GM voltage
regulator set points have been creeping steadily upward for decades and are now at around 15.4v, which is causing GM bulbs to fail early and often, especially those bulbs that are always on. The 4114 was devised as an ultra long life replacement for 3157/4157 in GM's trucks and SUVs with white DRLs, while 5702KA is the amber version for GM's vans and cars with turn signal DRLs".
We have a couple vehicles that approach the 15.vv range that Mr. Stern speaks of. The actual measured voltage at the bulb may be less on various vehicles but still give a good aproximation of how a bulb will perform.
Mainly playing around with different options for a DRL. The bulb in question is designed for the high voltage and I am considering the suitability of using it in a "normal" voltage situation compared to say a 3157A or 3457A.
Concerning the high voltage, in 2005 Daniel Stern stated, "The last two bulbs on the list exist because of GM's stupidity. GM voltage
regulator set points have been creeping steadily upward for decades and are now at around 15.4v, which is causing GM bulbs to fail early and often, especially those bulbs that are always on. The 4114 was devised as an ultra long life replacement for 3157/4157 in GM's trucks and SUVs with white DRLs, while 5702KA is the amber version for GM's vans and cars with turn signal DRLs".
We have a couple vehicles that approach the 15.vv range that Mr. Stern speaks of. The actual measured voltage at the bulb may be less on various vehicles but still give a good aproximation of how a bulb will perform.
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Alaric Darconville
Flashlight Enthusiast
You know, I'd forgotten the reason for the 5702KA; my numbers assumed the normal bulb with a design intensity voltage of 12.8V and a design life voltage of 14.0V. That's a bit of esoterica I need to brush up on.
Concerning the rest of the DRL "options"-- amber DRLs are only appropriate when it's incorporated with the turn signal. All other DRLs must be white. Additionally, unless the lamp meets the photometrics of a DRL, you can't just bolt on a lamp and call it a DRL.
What vehicle are you talking about? The DRL-1 module to move the DRL function from the headlamps to the turn signals may be a good choice instead of trying to add additional lamps.
Concerning the rest of the DRL "options"-- amber DRLs are only appropriate when it's incorporated with the turn signal. All other DRLs must be white. Additionally, unless the lamp meets the photometrics of a DRL, you can't just bolt on a lamp and call it a DRL.
What vehicle are you talking about? The DRL-1 module to move the DRL function from the headlamps to the turn signals may be a good choice instead of trying to add additional lamps.
Three vehicles, a 2003 Silverado, 2012 F-150 and 2007 Toyota Tacoma. All use the 3157A or 4157N as their front turn signal the Silverado uses the higher 14 volt bulb as a DRL...the 4114 white color bulb.
For the sake of my question let's say that F-150 and Tacoma produce 12.8 volts while the Silverado is one of the vehicles that the 14 volt bulbs were designed for. While it is presumed on the basis of Mr. Stern's writing that the 14volt bulb will be more than fine for the Silverado, I have questions about the suitability of using this bulb in a vehicle that is designed for 12.8 filament bulbs.
There is no doubt that 5702KA bulb is a very, very long life bulb, but will the results be suitable for turn signal/DRL use in "normal voltage" vehicles when using the DRL-1?
While many posts here are cautioned that to get increased brightness you trade longevity, I am wondering if the 5702KA trades long life for too little brightness in the 12.8 volt systems?
For the sake of my question let's say that F-150 and Tacoma produce 12.8 volts while the Silverado is one of the vehicles that the 14 volt bulbs were designed for. While it is presumed on the basis of Mr. Stern's writing that the 14volt bulb will be more than fine for the Silverado, I have questions about the suitability of using this bulb in a vehicle that is designed for 12.8 filament bulbs.
There is no doubt that 5702KA bulb is a very, very long life bulb, but will the results be suitable for turn signal/DRL use in "normal voltage" vehicles when using the DRL-1?
While many posts here are cautioned that to get increased brightness you trade longevity, I am wondering if the 5702KA trades long life for too little brightness in the 12.8 volt systems?
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Alaric Darconville
Flashlight Enthusiast
Assuming the 5702KA was designed to produce 302lm at 14.0V, and the F-150 or Tacoma feed it only 12.8V, that 302lm becomes only 222lm. That's more than a 25% loss. That could mean bringing the lamp out of compliance for any function. If the turn signal bulb also provides a front position light function (using the minor filament), the 19lm becomes 14lm. That's a valid concern!
The major filament's rate-of-rise, even if the filament had been preheated by the DRL use, means the turn signal will reach maximum brightness more slowly, as well.
