Interior LED's voltage regulator
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Joined: Jan 2010
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From: Glendale CA
Interior LED's voltage regulator
Over the years of working on my Corvette...there's one particular electrical gremlin that has pissed me off the most: blown out LED's
Those of us who have installed LED's in the interior should know that the LED's are meant to run at a max safe capacity of 12V....HOWEVER, our alternators (yes, I have volt-tested the interior sockets and confirmed) run around 14-15V
I kept blowing out my LED's in every socket: from corner lamps to the license plate blue LED's....ALL high-quality made but not meant for 14V, so I recently installed small regulators as a test behind my trunk LED's and BINGO! they have been going strong and havent burned out in over 2 years
I plan on working with my dad and installing a heavy-duty regulator on the control wires that sends power to the interior and park lights......just was curious if anyone has installed a main-power regulator to keep the alternator from sending over 12V to the car
Those of us who have installed LED's in the interior should know that the LED's are meant to run at a max safe capacity of 12V....HOWEVER, our alternators (yes, I have volt-tested the interior sockets and confirmed) run around 14-15V
I kept blowing out my LED's in every socket: from corner lamps to the license plate blue LED's....ALL high-quality made but not meant for 14V, so I recently installed small regulators as a test behind my trunk LED's and BINGO! they have been going strong and havent burned out in over 2 years
I plan on working with my dad and installing a heavy-duty regulator on the control wires that sends power to the interior and park lights......just was curious if anyone has installed a main-power regulator to keep the alternator from sending over 12V to the car
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Joined: Nov 2000
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From: Beverly Hills (Pine Ridge) Florida
LEDs are current sensitive, and must have a current limiting resistor in series with the LED. If the LED assembly is (meaning the socket and LED) is sold as a replacement for a standard light bulb, it always has the current limiting resistor already in the assembly. That resistor should safely limit the current for the "normal" operating range of the standard light bulb that the LED assembly is meant to replace.
All automotive electrical systems since the late 1950's (most US vehicles were changed from 6V to 12V in 1957) have been 12 volt. But the normal operating range for a 12 volt automotive system is 12 to 15 volts (depending on electrical load and charge condition of the battery), and all standard bulbs (and their LED replacements) should be designed for 15 volt operation (meaning they won't last as long at 15V as opposed to 12V, but they should last long enough). If your bulbs are not meeting a minimum life, then either your system is putting out more than 15V, or the LED assemblies are designed (or manufactured) poorly.
From an electical standpoint, say a LED has a normal operating current limit of 20MA. If the internal current limiting resistor is correctly specified for a max operating voltage of 15V, then a 750 ohm resistor would be used. At 12V, the same LED would only have 16MA of current, and would not be as bright, but it would be only a small difference in brightness (and the LED would last much longer).
For your application (if you were desperate), you could go through your electrical light system, and connect another current limiting resistor on each LED, but I would not recommend it!
I would just get a better brand of LED designed for automotive light applications, after I verified that you are not seeing any electrical spikes over 15V (your alternator could be the source of your short LED issues).
Plasticman
All automotive electrical systems since the late 1950's (most US vehicles were changed from 6V to 12V in 1957) have been 12 volt. But the normal operating range for a 12 volt automotive system is 12 to 15 volts (depending on electrical load and charge condition of the battery), and all standard bulbs (and their LED replacements) should be designed for 15 volt operation (meaning they won't last as long at 15V as opposed to 12V, but they should last long enough). If your bulbs are not meeting a minimum life, then either your system is putting out more than 15V, or the LED assemblies are designed (or manufactured) poorly.
From an electical standpoint, say a LED has a normal operating current limit of 20MA. If the internal current limiting resistor is correctly specified for a max operating voltage of 15V, then a 750 ohm resistor would be used. At 12V, the same LED would only have 16MA of current, and would not be as bright, but it would be only a small difference in brightness (and the LED would last much longer).
For your application (if you were desperate), you could go through your electrical light system, and connect another current limiting resistor on each LED, but I would not recommend it!
I would just get a better brand of LED designed for automotive light applications, after I verified that you are not seeing any electrical spikes over 15V (your alternator could be the source of your short LED issues).
Plasticman
Thread Starter
Pro
Joined: Jan 2010
Posts: 586
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From: Glendale CA
LEDs are current sensitive, and must have a current limiting resistor in series with the LED. If the LED assembly is (meaning the socket and LED) is sold as a replacement for a standard light bulb, it always has the current limiting resistor already in the assembly. That resistor should safely limit the current for the "normal" operating range of the standard light bulb that the LED assembly is meant to replace.
All automotive electrical systems since the late 1950's (most US vehicles were changed from 6V to 12V in 1957) have been 12 volt. But the normal operating range for a 12 volt automotive system is 12 to 15 volts (depending on electrical load and charge condition of the battery), and all standard bulbs (and their LED replacements) should be designed for 15 volt operation (meaning they won't last as long at 15V as opposed to 12V, but they should last long enough). If your bulbs are not meeting a minimum life, then either your system is putting out more than 15V, or the LED assemblies are designed (or manufactured) poorly.
From an electical standpoint, say a LED has a normal operating current limit of 20MA. If the internal current limiting resistor is correctly specified for a max operating voltage of 15V, then a 750 ohm resistor would be used. At 12V, the same LED would only have 16MA of current, and would not be as bright, but it would be only a small difference in brightness (and the LED would last much longer).
For your application (if you were desperate), you could go through your electrical light system, and connect another current limiting resistor on each LED, but I would not recommend it!
I would just get a better brand of LED designed for automotive light applications, after I verified that you are not seeing any electrical spikes over 15V (your alternator could be the source of your short LED issues).
Plasticman
All automotive electrical systems since the late 1950's (most US vehicles were changed from 6V to 12V in 1957) have been 12 volt. But the normal operating range for a 12 volt automotive system is 12 to 15 volts (depending on electrical load and charge condition of the battery), and all standard bulbs (and their LED replacements) should be designed for 15 volt operation (meaning they won't last as long at 15V as opposed to 12V, but they should last long enough). If your bulbs are not meeting a minimum life, then either your system is putting out more than 15V, or the LED assemblies are designed (or manufactured) poorly.
From an electical standpoint, say a LED has a normal operating current limit of 20MA. If the internal current limiting resistor is correctly specified for a max operating voltage of 15V, then a 750 ohm resistor would be used. At 12V, the same LED would only have 16MA of current, and would not be as bright, but it would be only a small difference in brightness (and the LED would last much longer).
For your application (if you were desperate), you could go through your electrical light system, and connect another current limiting resistor on each LED, but I would not recommend it!
I would just get a better brand of LED designed for automotive light applications, after I verified that you are not seeing any electrical spikes over 15V (your alternator could be the source of your short LED issues).
Plasticman
when we checked the output with the voltmeter, it read 14.8 directly at the socket....and the led replacement bulbs did have a current -limiting resistor.....though you may be right of poor manufacture since they all burned out in less than a month
I'd have to dig in this alittle deeper, and see what solution I can come up with. Thanks again
Race Director
Joined: Nov 2000
Posts: 10,340
Likes: 664
From: Beverly Hills (Pine Ridge) Florida
Much appreciated for the info Plasticman
when we checked the output with the voltmeter, it read 14.8 directly at the socket....and the led replacement bulbs did have a current -limiting resistor.....though you may be right of poor manufacture since they all burned out in less than a month
I'd have to dig in this alittle deeper, and see what solution I can come up with. Thanks again
when we checked the output with the voltmeter, it read 14.8 directly at the socket....and the led replacement bulbs did have a current -limiting resistor.....though you may be right of poor manufacture since they all burned out in less than a month
I'd have to dig in this alittle deeper, and see what solution I can come up with. Thanks again
14.8V is considered pretty much at the top of the charging voltage (with a pretty discharged battery). If it was without the engine running (no alternator charge taking place), then either your voltmeter is "off" (reads too high) or your battery is putting out too much voltage (or it was just very recently charged and topped off). Extremely rare for a battery by itself to put out too much voltage.
In other words, your "normal" voltage range with the engine running, with a good battery that is fully charged should be closer to high 13V to low 14V. Load will affact that (example: Put on the headlights and it should rise to the higher end of the range).
The battery by itself (no charging, and not recently charged), should be around 12.6 V or a tad higher (depending on state of charge and battery chemistry type - some read a tad higher). Certainly not 14.8V.
Plasticman
