Before we thought LEDS are only manufactured semiconductor devices. But, today we realised that LED lighting can actually be grown !
Using different materials, researchers have shown that different LEDs can achieve different wavelengths of light. Through which, we can have different application. Furthermore, Roberto Myers, a materials scientist at Ohio State University in Columbus, and his team has developed LED nanowires on a thin aluminium foil. This invention not only allow UV lighting to be generated, but also takes care of heat dissipation from the LED.
For example, a UV LED lighting made of aluminium gallium nitride is able to kill germs and bacteria in water. Combining this invention with a water filtration system, it may be usefully applied in different places to produce clean portable water.
Article by: Tan Chin Koon, NTU 3rd year EEE from Nanyang Technological University, Singapore
Journal: B.J. May, A.T.M. Golam Sarwar and R.C. Myers. Nanowire LEDs grown directly on flexible metal foil. Applied Physics Letters. April 4, 2016, p. 141103. doi: 10.1063/1.4945419.
Using natural body heat or temperature to light up LEDs
Many students these days are experimenting with peizo-electric theory to generate electricity and lighting things up. Combining this theory with the seeback effect, LED lighting is made possible.
Selecting the right type of material that will generate a charge due to temperature difference is critical in lighting up an LEDs.
The amazing thing about LED is the low voltage and current required to light up. This really enable many different applications and electrical generating methods to be applied.
E.g an awesome student in Canada using body heat to light up a torch light. All these without a need for battery.
This might just replace solar panels or be an additional arsenal towards our go-green campaign. This form or renewal energy is both free (from the body heat point of view) and seemingly perpetual.
If lightings can be stretched, how do you think we can enhance our spaces and minimise / reduce lighting costs?
Putting mechanical engineering considerations aside for now? We probably can explore the following;
1. LED Lightings as visual displays for smart clothing
2. LED Lighting for curve screens in Smart Phones
3. Smart LED Lighting for architectural facade (indoor / outdoor ("although challenging it may be"))
4. LED Lighting displays covering different surface area when necessary for advertising and creative industry.
By bringing mechanical engineering considerations in lighting, we might need to explore the following;
1. Stretchable host material for the LEDs where it is both conductive and insulated from touch.
2. Types of material for the LEDs that is able to light up with movable conductive electrical supply
Indoor lighting is always a critical component for all types of buildings. Recent trends of green building brings forward designs that utilises windows, sun roof or even large openings where natural sunlight can reach inside a building easily.
While this green movement serves to conserve lighting energy, it also directly benefits the people working within the building by exposing them to natural lighting. We can then explore the concept of cicadian lighting systems; the pros and cons of natural lighting to our body biological system.
Following the sun set and sun rise cycle, the natural light emitted from the sun varies in intensity and color temperature and we may have very strong dependency with the sun cycle. Circadian lighting design is meant to simulate the intensity and color temperature of the sun cycle to promote productivity at work and a relax atmosphere reaching the end of the day.
To achieve the respective intensity and color temperature, lighting industry have come out with tunable white LED where it can produce various color temperature via dimming of intensity and a control system that is capable of changing the intensity at real time. This is still a relatively new concept as the science and lighting technology have not yet merged together completely but companies in the United States are getting them installed improve productivity.
I feel that it would be necessary for circadian lighting design to advance further. With the flexibility and stability of LED lighting technology, there is the potential to provide more lighting design to benefit our human body and internal body clock. Gradually, the benefits may encourage more research into a better tunable bulb or white LED that have a wider and precise range for the color temperature.
Article written by: Mr Tan Chin Koon, 3rd Year Nanyang Technological University, EEE
Laser diodes to be the next LED lighting development - Is this possible and how feasible it is to our real life general lighting application?
Theoretically, if we place 2 mirrors on each side of the LED, the wide beam light throw effect from the LED will be forced to reflect internally within the 2 mirrors resulting in a more focused light beam.
This might mean that we need to create a light path for the LED in order to achieve the effect. This would be similar then to using fiber optic as a light guide.
All in all, can lasers replace LED Lighting? In my own opinion, i doubt so as general lighting requires a wide coverage at the lowest possible power input. Lasers will not be able to achieve an even wide coverage.
We've always loved the multiple solid hues put together in a lighting fixture.
It adds a sense of permanent vibrancy to any living spaces. A standalone lighting fixture without the need to have lighting passing through it.
Let us know if you are keen to explore such fixture and we might just make one specially for your space. It will be a one and only lighting fixture !
We'd described the pros and cons of direct AC ('Alternating Current') 2 years ago. Today we re-examined the following;
1. How does the AC LED lighting actually work?
2. Re-examined the pros and cons of direct AC Led lighting / luminaire.
- In summary, LED lighting is still using the DC (Direct Current) principle to operate.
- We make use of electrical components (some people call it IC driver) to alter the input AC power.
- First, one must understand that AC wave form is a sine curve with both positive and negative crests / trough. (Look at the pictures below)
- The IC Driver will flip all the negative curve upwards. So one get a series of positive crests only. (It will then look like a ridge mountain in Nepal or the French Alps)
- Next the driver will slice only the top part of all the crest from left to right. It is like taking a ruler to link all top part of the mountain together with a tangential line.
- We surely cannot have a perfect straight flat line (Direct Current) depending how close you examine the curve.
- But, this would achieve an effect that is as close to a straight flat unbroken line which might just be good enough for the LED lighting to work well.
Creating DC power from AC
• Alternating Current or AC is a voltage that varies over time as it is delivered by the power company. To be used in LED Lighting/luminaire you need to convert the AC into DC using a bridge rectifier (turning AC in to pulsed DC) and then filtering (smoothing the pulsed DC into a continuous DC).
Filtering - Passive components are used to smooth the rectified signal to a constant DC voltage. Without control, the output voltage will fluctuate with input voltage.
Further to the above, our personal opinion on a strong advantage for AC LED lighting comes on the back of the recent breakthrough in thermal control for the IC driver. With this heat issue under control, AC lighting should start proliferating the LED lighting industry soon.
Article contributed by Leong Weisheng and team from Illuminating Asia Sg.
Arduino, Photocell and LED Lights for SMART CARS, Signaling, Life saving training equipments and common sense uses
Very often we have photocell used as a sensor to determine how much one LED lighting fixture should dim or light up.
Do you know that photocell can work well even in a broad day light condition easily and cheaply?
Through our experiments with Arduino and photocell sensors, we have found many more quirky, interesting and common sense applications with LED lighting.
1. A smart vehicle with photocell attached to head lights or back lights.
- Your cars' back / head light can light up automatically when a tailgate car comes too close or you are following too closely to some cars infront.
- The shadow / reduce incident light to the photocell will automatically light up your cars' head lights!
- The best part is that the light intensity gets higher as you move closer beyond safety limit.
1b. This can also be applied by the traffic police, LTA or drivers for sending out signals for whatever purposes they need!
2. Training equipments that uses a photocell as a simple sensor to detect correct posture.
- E.g. During CPR training, the trainee position will block the photocell well. This will trigger a green light to light up informing the assessor the trainee is position correctly.
There are more uses beyond child's play in this and we look forward to hearing from anyone with a project in mind! We're glad to share how to get things done !
Illuminating Asia, leader in LED lighting technology application, LED lighting Singapore, presents a simple set up of LED lighting reacting to music with the use of Arduino chipset. - Done by Leong Weisheng from Illuminating Asia!
Lightings with smart control and music to make things exciting !
Building on our expertise in LED lighting technology application, we now add the element of sound to lights. Through the know-how with micro controllers like Arduino, things can be made simple!
This simple video shows only the basic. Does this reminds us of the battery operated lanterns that comes with music which we use to carry around when we are younger?
Contact us if you have any lighting projects to explore !
In our pursuit of technological advancement in LED lighting controls and lighting effects; we present our latest set up Arduino control and LED lighting.
Arduino controls replaces the bulky hardware and systems earlier associated with Lighting controls.
Also, we are able to connect wifi/blue tooth modules for wireless connectivity.
With it, an end user is able to quickly program LED lighting effects to suit different projects.
From running a marketing campaign with lights to lighting monitoring systems for inventory management systems; Arduino is a convenient tool to work with lightings.
The accessibility to dim and control timing for the LED lightings will surely be a start to great lighting displays!
Illuminating Asia is delighted to share a snapshot of our Arduino capabilities with LED lightings. Call or email us if you have any lighting projects to kickstart!