by Dan Meeks @ edn.com:
A long, long time ago there was a great Design Idea for a simple gadget to find a bad bulb in a series-connected string of Christmas lights. This is really simple and works great, but it exposes the user to potentially lethal line voltages. The PROBE in the figure above is inserted into the light bulb bases, so there is a good chance that you could be touching a part of the probe, while the probe is touching line voltage.
Bad-bulb finder fixes Christmas lights - [Link]
This project provides some lighting effect by the blinking pattern of the bulbs connected at its output. Up to 8 Bulbs can be connected in between connector CN2 to CN9 and AC power to control them should be connected at Connector CN10. DC Power should be applied at Connector CN11 in accordance with the polarity marked on this connector. Care should be taken while using this it as it contains Main Power on the board.
Microcontroller based running light controller - [Link]
Pulse-controlled dimmers of lighting – Finder series 15 offer an elegant solution of lighting dimming controlled by a single switch.
Possibility to control level of lighting is beneficial at least from two reasons – saving of energy and naturally – we don´t need always a full intensity of lighting. At watching of media-projector presentation, TV, illumination of corridors, … it´s often desirable only to reach only a minimum level of illumination (but not a total darkness). Light dimmers are for a long period used for these purposes, usually based on a phase regulation.
Solution from company Finder is exceptional in a fact, that it´s usable with almost every light source – for example incandescent bulbs, 230V halogen bulbs powered by a toroidal or EI transformer, dimmable CFL lamps, as well as LED bulbs. The essence of Finder 15 series dimmers versatility is in the possibility to choose a method of a phase regulation – on the beginning of the sinusoid, or on its end (leading/ trailing edge – the difference is illustrated on the attached picture). The first method is generally suitable for electronic transformers for halogen bulbs and LEDs, the second method is better for classic transformers for low voltage bulbs, for 230V CFL and for 230V LED lamps.
As it uses to be, control of such dimmers is maximally simple – by a short push of a control button (switch) the relay (output) will switch on or switch-off. By a longer holding the button presses, we can change the light intensity from minimum to maximum and vice versa. Finder 15 series dimmers also enable to work in a mode with a switched on memory (after a repeated switch on, the last used level of intensity will be set) or without a memory (after switching on, the maximum intensity will be set). An above standard benefit is a possibility to adjust a minimum light intensity by a potentiometer, what´s important mainly at electronic transformers to avoid a possible blinking at very low intensities and it´s also at classic incandescent bulbs, as their efficiency drops down rapidly at very low intensities (duty cycles).
All 3 produced types are available directly from our stock:
18.104.22.168.0404 – assembly to installation boxes, linear dimming (also available types with dimming in 10 incremental steps)
22.214.171.124.0500 – assembly to boxes or on a panel, linear dimming
126.96.36.199.0000 – DIN rail assembly, linear dimming
Available are various versions, detailed information and a comprehensive table about possibilities of usage of particular types will give you the Finder 15 datasheet.
One impulse is able to set intensity of luminance - [Link]
Mr.Fishers3 @ instructables.com writes:
Ever looked at a lightbulb and thought that doesn’t look too complicated, I bet I could make one? With this Instructable you can!
This lightbulb is made entirely out of simple, mostly household materials requiring very little in special equipment. The basic construction includes a glass jar filled with CO2 and a graphite filament(Pencil Lead). This makes it a carbon filament bulb analogous to those made by Edison before tungsten became the norm.
Homemade Lightbulb - [Link]
by Dave Young:
A month ago Newegg sold the 40W-equivilant Collection LED for $5 each. This was the first time I saw LED bulbs going for almost as little as CFLs, so I picked up a few. Not having bought LED bulbs before I did what any normal person would: I tore it apart!
40W ‘Collection LED’ Bulb Teardown - [Link]
A project with only 2 parts, but is great for addressing an everyday situation that is irritating at best and dangerous at worst. This circuit protects the bulb in flashlights from high switch-on current to make the bulb last longer.
For a standard incandescent flashlight, this is a easy little modification make your flashlight bulbs last longer. High powered flashlights typically run their bulbs hot to get a brighter light from them. They also have a much lower on-resistance when cold, so that when you turn them on, the bulb passes a much higher current than it was designed for. This is why the most common time for a bulb failure is when turning it on.
The transistor and resistor limit the current while turning on the circuit and protect the bulb from an initial high current turn on. A simple resistor in series with the bulb might be a tempting option, but there are a couple problems with that approach. Just adding a resistor would reduce the voltage available to the bulb, and aid longevity, but that would reduce the brightness. The resistor would also be wasting energy getting hot instead of using that energy for light. This solution is better in that it limits current at startup and wastes very little energy when in use and when off.
In this application, it might be easier to insert the batteries in the flashlight “backwards” so the circuit connections and parts have the best fit in the body of the flashlight. Flashlight design was stagnant for decades, but now there are many new technologies available, and in some cases, it can even be easy to bring some of them to an older one you already have. In addition to this circuit, you could also take advantage of newer LED and battery technology to really increase the brightness, “on” time, and lamp life of your old flashlight.
Soft Start For Flashlights - [Link]
Richard Comerford writes:
The first LED replacements for 60 W incandescent bulbs are now appearing on shelves in local stores across the United States. Although current U.S. law will phase out only 100 W incandescent bulbs in 2012, one can easily find replacements for incandescent bulbs of other wattages – 15, 25, 40, 60, and 75. The initial cost of the LED bulbs is relatively high, but they more than pay for themselves over time with their longevity and energy savings.
The LED bulb that has received the most attention so far is the AmbientLED Model 12E26A60, a 12.5 W, 800-lm replacement for 60 W incandescent bulbs made by Philips Lighting (Figure 1). It is similar in configuration to the bulb that won the U.S. Department of Energy’s first Bright Tomorrow Lighting competition, or L Prize. It was also declared a standout among the CFL and LED bulbs in lamp and ceiling fixture tests conducted by Consumer Reports magazine.
Inside the New LED Retrofit Bulbs - [Link]
Step by step instructions for how to build and implement the replacement surgical lamp bulb system using an LED circuit developed by Mohammed Shafir and Zoe Englander as part of the course BME 262-Design for the Developing World at the Pratt School of Engineering, Duke University.
Replacement for surgical lamp bulbs using LED circuit – [Link]