Hi,
I'm currently thinking about making a small bedside lamp and I'm in the process of understanding the design space by considering potential emitters, drivers, controls, dimmers, power-supplies...
My current thoughts on it are the following.
To fix a few ideas here are a few constraints/estimates I was thinking about, all being challengeable:
Emitter
As far as the emitter go, I was initially targeting high CRI (>92) and low temperature (~2700K) to get a warm and cosy natural feeling. From what I read down here I understand that things are not as simple as this and that high CRI and 2700K do not guarantee a 'natural' bedside ambiance.
What kind of leds should I look for if my goal is to have a pleasant light and I cannot rely on simply selecting highest CRI and lowest temperature I can get?
A few specific led manufacturers I've been looking at:
Power supply
I don't want the power supply to be an afterthought as it can be hard to find a good quality and compact power supply in the 15-20W range that I'm considering. The integrated one are often a bit underpowered (Example) or have a voltage which requires to be boosted and limit driver choice (Example) or are fine but bulky and ugly (Example).
A fun power supply I'm considering is the... Apple 29W usb charger which can deliver can deliver 2A @ 14.5V and might be of excellent quality (http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html). It would requires a Power controller chip though (Example) Standard USB Power Delivery protocol even allows 5A at 20V
Driver
I'm considering a driver that would allow to easily dim the led through a potentiometer such as http://www.ledsupply.com/led-drivers/buckpuck-dc-led-drivers It would requires the led forward voltage to be below my power supply output voltage though.
I'm currently thinking about making a small bedside lamp and I'm in the process of understanding the design space by considering potential emitters, drivers, controls, dimmers, power-supplies...
My current thoughts on it are the following.
- My main goal is to have a pleasant bedside lamp. By pleasant I'm thinking about the quality of light, but also of the lamp and its ergonomics (Switching and dimming the lamp, moving it, plugging it to a wall...)
- An important constraint is to keep things simple enough for me to actually be able to make the lamp and not add it to my ToDo pile. Keeping in mind that it is my first lamp project.
To fix a few ideas here are a few constraints/estimates I was thinking about, all being challengeable:
- Max luminosity around 1000 lumens (Balance between having enough light to influence room ambiance in the evening and keeping things small and cold enough).
- Dimmable to low levels. It doesn't have to be continuous but I do like the feel of a smooth potentiometer and light dimming.
- Non audible electronics.
- Non visible flicker even at low levels.
Emitter
As far as the emitter go, I was initially targeting high CRI (>92) and low temperature (~2700K) to get a warm and cosy natural feeling. From what I read down here I understand that things are not as simple as this and that high CRI and 2700K do not guarantee a 'natural' bedside ambiance.
What kind of leds should I look for if my goal is to have a pleasant light and I cannot rely on simply selecting highest CRI and lowest temperature I can get?
A few specific led manufacturers I've been looking at:
- Xicato which some CPFers seem to rave about. Xicato modules do not seem to be thoroughly available to purchase though (But I was able to find one on eBay) And they seem quite expensive.
- Sharp Zenigata leds seem nice.
- Bridgelux
- Cree
- Osram
- Nichia (Which advertises a Candle Color range (2580K-1870K) which sounds interesting for a cosy feeling but I couldn't find any emitter below 2700K)
Power supply
I don't want the power supply to be an afterthought as it can be hard to find a good quality and compact power supply in the 15-20W range that I'm considering. The integrated one are often a bit underpowered (Example) or have a voltage which requires to be boosted and limit driver choice (Example) or are fine but bulky and ugly (Example).
A fun power supply I'm considering is the... Apple 29W usb charger which can deliver can deliver 2A @ 14.5V and might be of excellent quality (http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html). It would requires a Power controller chip though (Example) Standard USB Power Delivery protocol even allows 5A at 20V
Driver
I'm considering a driver that would allow to easily dim the led through a potentiometer such as http://www.ledsupply.com/led-drivers/buckpuck-dc-led-drivers It would requires the led forward voltage to be below my power supply output voltage though.