LED Bulbs Change Everything

[flmark]

In case your paradigm of a light bulb involves only standard, medium based screw-in bulbs, you should visit some web sites and explore the possibilities of an energy makeover. For example, there are wedge-based bulb replacements http://www.superbrightleds.com/cgi-b...%2FWLED-x5.htm and prong-type (G4) bulb replacements http://www.superbrightleds.com/cgi-b...-pin.html%23g4 I employed some of the former type to replace bulbs in low voltage outdoor lighting, but that is where the fun just begins.

Unfortunately, many folks might just stop at the Kill-a-watt reading and think they’ve got the whole story figured out. First, LEDs gain in efficiency is because they don’t waste (much) energy as heat. Halogen bulbs are becoming the rage, but they are incredibly HOT- and all that heat could indeed require more air conditioning to remove it. I scoff at the idiots who are trying to protect the ‘right’ to waste energy via conventional incandescent bulbs, scheduled to depart store shelves in the near future. From the air conditioning, to the copper in the conducting wires, to the surplus power generation required, no one has the right to rob society in this way- now that we have awesome alternatives.

If there was a way to mine the copper out of circuits that no longer need amperage to support incandescents, LEDs would more than pay for themselves in materials alone. And I would like to think new construction projects would offer wiring savings in this regard, but our draconian electrical codes would never allow an ‘enlightened’ approach to right sizing circuits.

As mentioned, I installed 18 wedge based LED bulbs in a deck railing lighting circuit that I was loathe to use since I bought the house in 2007. However, LEDs have given me the freedom to use decorative lighting without guilt (or waste). The amount of electricity consumed by all eighteen of these LEDs (4 watts) is less than what ONE of the previous bulbs consumed (5 watts). And the lighting is superior as well.

However, the real lesson of this story doesn’t begin until now.

I had a feeling, and the Kill-a-watt confirmed, that the transformer/timer energizing this 12v circuit devalued everything else. Online research, and perusing the home improvement stores, will accomplish nothing without some common sense as a guide. Every solution I found was no solution at all. What are out there are bulky, wasteful transformers that in no way consider the miniscule LED load being energized. Twenty four hours a day, 365 days a year, the previous homeowner left this ridiculous box humming away, awaiting the call for this hand rail lighting. Another (for a circuit I removed) hummed right along, by its side. As measured, each transformer wasted 12 watts. This 105 kwh wasted annually would be enough to cover 2 weeks of commuting in the Volt.

My solution? Stop at Radio Shack and look for a transformer that only needed to supply the <1 amp necessary for this circuit. The box is comparable to a cell phone charger- in size and cost. And they are apparently making these small transformers smarter these days. Measurements showed zero watts consumed when no loading was present. So the four watts of LED bulbs was all that showed on the Kill-a-watt. No more paying for 12 watts 24/7 to occasionally run a 4 watt load. And two free weeks of driving, to boot.

Of course the saddest part of the wasted resource realization was noting the few copper fibers coming from the new transformer (comparable to the hair in your nose) coupled to standard gage wiring that led off to the rest of the lighting circuit. Unfortunately, no one wrote in my name at the Iowa Straw Poll last week so that I could do something about this huge waste of copper. I have often told folks that I believe future generations will be mining our landfills for valuable resources we currently discard with abandon. At least copper is valuable enough to be salvaged in our modern era.

[Solar EV]

Great post!

So the question for my fellow Volt owners is -> has anyone gone through all the bulbs used on the Volt and identified what bulbs it make sense to be replaced by LED's? A little project I thought of doing but have not had the time. If anyone has looked at this let us know!

[therfman]

I have built an off-grid exterior lighting system at my house using LED lights. I use a 30W solar panel on my shed to charge a simple deep-discharge lead-acid battery during the day. At night, a flick of a switch turns on LED lights that light the inside premieter fence and gardens below as well as the deck and gazebo. I also run a wireless outdoor speaker on the system on an inverter and actually have enough power to connect a laptop if working outside. I experimented with timers to turn the lights on and off automaticaly, but all the ones I tried would use 5-10W around the clock, and that rapidly depleted the battery, so I reverted to a switch.

The system obviously doesn't work in the winter. But then again, the yard gets many feet of snow at that point any nobody goes out back, so it doesn't really matter.

[larry4pyro]

I've been using LED bulbs for about 3 years. There are a number of issues I've had with them:

1. Color variation. I use Warm White LEDs which produce a light similar to an incandesent light. However I've found the color of the light produced varies quite a lot. I've purchased bulbs from China and US distributors that are totally useless for indoor use as they have a terrible sickly green tint. These bulb do work fine for landscaping lights. Even when the produced light is the correct color, I find enough variations that I have to use bulbs from the same manufacture when multiple lamps are used in close proximity.

2. Color Spectrum. I used LEDs for in-cabinet lighting. Their low power consumption makes them ideal for installation in places where cooling is not available. However, the light produced is inferior to halogen incandesent bulb. The result is a "flat" appearance that does not give objects the "sparkel" of ordinary incandesent light. This is important in a display cabinet.

3. Life Span. LEDs are advertised as having extreme longitivity. I'm not finding that to be the case, I had 3 out of 11, 120 volt indoor bulbs fail in three years. These were purchased at great cost (about 30 bucks each) when LEDs were first being introduced. They may be more reliable now. I've also had a number of landscaping bulbs fail, but these were cheap bulbs from china there were not intended for outdoor use. Usually they are glued together and the bulb simply comes unglued and falls apart.

So, I've had some problems with LEDs but on balance I'm more happy than not. Their low power consumption is amazing and their small size and low heat allows them to be used in a number of inovative ways.

[flmark]

larry4pyro,

I would agree that LED lights a few years ago had many of the issues you describe, especially in warmer temperature environments. However, I believe you would find that current purchase options are much more rewarding. From expanded color options to dimming to reliability and consistency, the offerings are pretty good these days.

[stuart]

Great post!

So the question for my fellow Volt owners is -> has anyone gone through all the bulbs used on the Volt and identified what bulbs it make sense to be replaced by LED's? A little project I thought of doing but have not had the time. If anyone has looked at this let us know!

A while back there was an active thread which talked about replacing the backup light. some folks used led license plate frames, I suggested (and installed) a 25 led replacement for the 3157 OEM bulb.
Here's the link to that thread: http://gm-volt.com/forum/showthread....-Back-up-light
The back up light, and the image in the backup camera are much brighter now.
Stuart #2209

[Raymondjram]

Although many may not believe this post title, there are many LED lamps that can operate up to 270 AC volts with no transformers. The secret is knowing what the LED is: a Light Emitting Diode. The Diode only needs a few volts ( also known as Forward Voltage Drop) to operate at a certain current. Let's take 4 DC volts as its operating value. So you assume that you have to convert the 120 AC volts to 4 AC volts first. That is not needed! What you do need is a voltage sink, or a device that will drop the excess voltage, and for that you can use two other items: a resistor or a diode. The resistor does by Ohm's Law: V=IxR, and that excess voltage will be converted to lost heat: P=IxIxR. But a diode will only drop a few volts and Ohm's Law doesn't apply.

But what if you use more LEDs to drop that voltage and get more light output at the same time? So if you had thirty LEDs in series, they will drop about 30 X 4 = 120 Volts. Actually the when AC is converted to DC, the peak or maximum voltage is 1.73 times the average (also known as RMS) AC value, so a household AC circuit has an average of 120 Volts, and when rectified can reach 120 X 1.73 = 207 volts DC peak. So you need more LEDs or add the resistor. But how large can that resistor be? Now we use Ohm's Law again!

So to build a LED lamp to operate on a 120 AC volt circuit, we need two values: the LED forward voltage drop and the operating current. If we had an ideal LED that operates with 4 volts DC on only 20 milliamps (20 mA or 0.02 A), let's put forty in series (4 x 40 = 160), and let the resistor take up the difference (207 - 160 = 47, and 47 / .02 = 2.45 K ohm. Add a 300 VDC silicon diode in series to protect the LEDs for the reverse voltage (or add a few more to create a diode bridge and use both cycles of the AC circuit [I can explain later]), and all of the components can be soldered in series and placed inside a thin tube.

Actually this is already sold as LED ropes, and as replacements for the fluorescent tube. I bought a few 48-inch lengths, attached 120 AC volts, measured the current, and saw that they consumed less than twelve watts for more light output than the normal 40-watt fluorescent tube. And they don't use or need the ballast!!! One of the tubes is completely transparent, and all the LEDs are surface mounted on a long white printed-circuit board inside the tube, so I did a reverse engineering and that is how I discovered that a series of LEDs and one resistor can operate at 120 VAC without any transformers.

In actual designs, the total drop must be measured before calculating the resistor because not all LEDs are manufactured equally. And my sample tube had 160 LEDs using four strings of forty LEDs each, so the current increased to about 60 mA , which calculates to about 12 watts. Obviously the amount of LEDs is determined by the amount of light you need.

In a vehicle, the maximum voltage is around 16, so a single LED needs a bigger resistor value to drop the excess voltage as heat. I recommend using more LEDs in series, so the resistor is smaller and less heat is lost.

[excess_3]

for the home, compact flourescents are 95% as good as LEDS,
and CFLs cost next to nothing.
......................../
for the car, headlights are only 55 watts or so,
which is nothing compared to the power needed by the wheels

[MTN Ranger]

for the home, compact flourescents are 95% as good as LEDS,
and CFLs cost next to nothing.
......................../
for the car, headlights are only 55 watts or so,
which is nothing compared to the power needed by the wheels

I agree. I replaced almost all of the bulbs in my house with CFLs about 5 years ago. I have only had 2 go out on me (out of over 50) during this time. Most of them cost about $2-3 each due to buying bulk. Right now an equivalent 60W LED is 10x the cost.

[daryllafferty]

for the home, compact flourescents are 95% as good as LEDS,
and CFLs cost next to nothing.

The one application where I have found LEDs superior to CFLs is for my kitchen ceiling PAR30 bulbs. Since these are encased in a plastic shell, which increases the heat, the compensating CFL design makes them slow to come to full brightness. The LED bulb I put on one of the sockets stands out for its brightness when the lights are first turned on, and that corner of the kitchen is much brighter than the rest.

Within 5 minutes the CFLs come to full brightness, and then you can't tell the difference.

I agree that for normal bulb replacements a high quality CFL is just about as efficient as an LED, and just as usable.

A little off-topic for a Volt forum...