10 Watt Halogen light bulbs

[yolo]

... I suspect that the economy LED's using resistors waste a high percentage of the power as heat rather than producing light as compared to regulated LED's. Individual LED's drop about 0.5V. In combination; some light is probably lost by ensuring adequate voltage drop to keep all of them conducting at lower input voltages or they will burn out quickly.

The LEDs each use about 3.5 volts and they are wired 3 at a time to use 10.5 volts.  The dropping resisters only have to drop 3 to 4 volts.  They don't get that hot warm.

I used to build automatic anchor lights for my boat and used 10.5 volt regulators like the 7810 series and the regulators really did get hot dropping the 3 or 4 volts for about 200 ma of current.  The cheap LEDs don't seem to run any hotter than the high priced versions with the pulse code modulated regulators.  That type of regulator makes the LED brighter by sending a higher voltage through the LED for microseconds on and off.  The result is that the bulbs still get warm.  Something has to dissipate the higher voltage used to power the LEDs and their regulators or dropping resistors.

 

[Ernie n Tara]

I have no idea whether multiple leds are combined to make up the LEDs,  but individual semiconductor junctions do drop about 0.5V.

Resistors do dissipate power as heat. A pulse width type regulator does not conduct during the OFF part of the cycle and therefore does not heat during that part (which is likely a large part of the cycle). The only heating, neglecting the switching part of the cycle, is due to the junction loss during the conduction part of the cycle (a very low relative level; 0.3 to 0.5V as compared to about 3V continuous from the example given above).

Power disipated as heat by the Resistor type LED is certainly higher, and likely much higher, than the Pulse type. The above suggests 6 to 10 times as much; still less than a third as much as the G4 bulb.

The 7xxx type regulators are analageous to a variable resistor and do heat (they are used where pulse regulaion would generate unacceptable noise levels).

Ernie

 

[JCMSr]

I have experienced the same problem with the G4 halogen bulbs as the OP.  During the first year it seemed like we were replacing bulbs weekly.  As a test our dealer replaced about six fixtures and that seemed to stop the problem....for a while.  I believe that the main problem is fingerprints on the bulbs causing them to overheat and burn out prematurely.  When they first started burning out I purchased replacements at Lowe's and other local stores but at $3 + each that got very expensive.  I now buy them on the web for around $.34 each.  I looked into changing everything out to LED's but with a total of 36 fixtures this would be way too expensive.  I did manage to get DW's permission to change out a few bulbs to LED which are over the area when I normally sit to surf on the computer and watch TV and the difference in the heat output was a welcome change.  Don't think I can talk her into changes the rest of the bulbs out mainly due to the color the bulbs put off.  Unless someone has a new product out it seems that the LED's either put out a green glow (cool white) or a blue tint (standard).  Guess I will have to stick with purchasing the regular halogen bulbs in bulk.

 

[afchap]

the color the bulbs put off.  Unless someone has a new product out it seems that the LED's either put out a green glow (cool white) or a blue tint (standard).

I have bought several ARRAY PREMIUM LED G4 at Lowes. They are 12v 1w. I paid $8.08 ea. The brightness and color are so close to the original 10w Halogen that I can't tell which fixtures I have changed w/o looking at the bulb.