Actually your living area need six downlights, 18w should be OK yet it depends on your ceiling height.

If you really want to make sure the brightness can ask if your contractor for lux meter to measure them on site for you.

He said, 4 downlight enough. If put 6 downlights will be very bright. I also don't know.

What do you think? (attached).

All areas will use 6" downlight(18w).



This post has been edited by xphr3ak: Jun 4 2020, 03:40 PM

I just realize there are yellow colour rectangular on the living area, is that a ceiling light trough?

if yes the 4 downlight lights at living should be ok when you open both of the lights at the same time.

Yes. That's light trough. Plan to use this light when watching TV and want cozy feel(warm white).

Downlights will be used when need more light(cool white).

Thanks a lot ehwee

Today mark 4 years 6 months usage of the Yetplus 6" LED downlight in my house.

Usage pattern 6 hours per night constantly for 12/39 of the lights, total hours is approaching 10k mark at 9.85k hours/light now.
None of them malfunction until now, but the intensity test using lux meter did shown degraded to 80% of original brightness when compare with those that seldom turn ON.

I won't say the brightness is durable, but the driver reliability is quite remarkable in my opinion.

This post has been edited by coolkwc: Jun 10 2020, 01:07 AM

my philips LED MR16 bulbs and Philips drivers also still working after 5 years. Not sure about the brightness but I think some of my lights had change color temperature from 4000K to something more yellow. Not all of them but some of them

Walau reminds me korek back my old testing led post.

--> https://forum.lowyat.net/index.php?showtopi...post&p=72026734

8yrs now the 1st downlight LED install.

12hr ON daily for 8yrs = 35,040hr and counting.

Later evening check the brightness.

What surprised me is not the LED. But the laptop IBM power supply that can last so long. I put it inside the roof which is so hot and dusty to abuse it.

I'm not sure whether your good lifetime is affected by under current LED or not.

Looking at your testing 1 and 2, i think you make a fundamental error there. 1st LED is constant current driven components, current decide brightness, not voltage. Whereas voltage is a by product of LED forward bias. Normally in LED driver, 2 specs was printed which is open circuit voltage, and current rating. That current is constant that will be sensed and controlled by tye driver.

You measured 17V from original PSU doesn't mean the PSU is output 17V. It means when series of LED running with xx current, the total series LED forward voltage is 17V and it clamp the PSU output and it will change based on tenperature. The hotter the LED, the smaller the forward voltage, and larger of LED current. So the driver current sense will adjust it so that the LED current is constant throughout the operation. One improtant things, the open circuit voltage of LED driver will be higher, say the LED forward is 17V, the open circuit voltage that the LED need to supply will be higher than that.

Your method of modifying is using constant voltage method, and only able to provide 16V in default as oppose to 17V, which means it will not provide enough current same as original design. In LED a slightly drop of forward voltage can means a huge reduction in current provided temperature is same. You can read the VI curve of LED online. This explain why your power reading is lower. It also means your LED can last alot longer because it operate in much lower current, perhaps 50 percent of intended current.

Furthermore i'm not surpise the laptop PSU can last so long time provided you only use perhaps 10 percent of the maximum capability. I based it with 5W per 50W max.

Anyway i did not read your following post except those in your link, so i'm not sure whether u found the answer afterwards or not. Really sorry if your 8 years test is not valid.

This post has been edited by coolkwc: Jun 14 2020, 01:29 PM

You already telling me the answer?

But I not so agree with you from my simple modification. That looks like found a solution for the long-life LED. Doesn't the manufacturing know this solution? ( I can patent my finding? )

I think a constant voltage with variable current draw will be better? Since the voltage been clamp down for overdrawing by the LED that might burn it down.

I do agree that the laptop PS is overkill for the LED. That might be why it lasts that long. Not mistaken the PS is 80-90w. Which not be running efficiently.

I have another LED strip setup in the hall at the AV cabinet. Running on the solar battery with a constant voltage on 12VDC and variable 24VDC. From the watt meter checking, it tell me the current fluctuates when the voltage is changing. So I don't see the LED is a constant current.

My further setup planning is to install another 1-2 of this LED downlight. And using that existing PS to run. Once the CFL bulb dies later.





Yesterday check the brightness of the LED. Didn't use a ladder to get nearer. So I m holding the meter about 100-120mm away. Expecting slightly lower reading compare last time.

The reading is not much different from the previous.



8yrs ago.

Sorry to say, you have no idea how the LED works because you are not in that field.

The current to LED need to be constant to achieve constant light output, and the constant current is controlled by the driver (PSU), not LED itself. They are two majority output control in PSU, which is constant voltage and constant current. Constant voltage suitable for load that varies the current based on dynamic load such as motor, computer and others majority of devices. Constant current is for load that need to strictly maintain its current throughout its operation such as LED and Li-ion battery charging.

I respect your passion and interest on electronics, but i just can't agree because it was wrong. Just let you know my background this year is my 11th years in EE field, currently work in local R&D centre of famous UK brand home appliances and we do design LED lighting that claim to withstand 40 years lifespan. I'm happy to exhange the idea if you would like to know more about LED driver design.

This post has been edited by coolkwc: Jun 15 2020, 09:19 PM

hi, anyone has experience using this type of wireless sensor light? is it good for lighting up small passage like entrance?

Hello, can guide me a bit? Our new house lighting point is something like this, blue is light and orange is fan. Ceiling height around 3.3m. For living room (16x20ft) and dining (8x20ft)



Is any LED 24W is enough for living area? We dont plan to install plaster ceiling at the moment due to budget constrain. We saw philips moire series. Is it good? Is there any recommended brand other than philips?

I read somewhere, daylight led is too white/blueish compare to warm white? Is it true that warm white is more closely ressemble normal cfl tube?

Dining area we plan to install those hanging light only. Maybe warm lighting only.

Thanks guys..

This post has been edited by wuwah: Jun 19 2020, 12:08 AM

Philips Moire vs marcasite LED lights anyone? I know one is downlight and the other is ceiling light, but other than that, any other pro/cons?

I am currently using downlight with Phillip 18W E27 CFL bulb (from online specification it is 1100 lumens)
Is it correct to say that compare to a 13W Phillips Meson LED downlight (lumens 940), the LED will be dimmer?

Yes in theory if you're looking at the bare CFL bulb vs LED downlight the CFL is brighter.
But in practice the old school "hole in ceiling" holder type for CFL wasted some lumens shining the "hole in ceiling" rather than pointing direct to the floor (like the flat output surface LED downlight)

What about the philips LED that look like the UFO, its a flat LED downlight but is E27 and can fit in 6 inch holder type.
Am leaning towards that cos afraid to destroy plaster ceiling while changing light.

ahh... true.
that make sense.
Because I am contemplating whether to get back the same lumens for LED or not.
If any of the forummers have any experience of this in real life too do share .
Thanks in advance

Brought some Mr.DIY LED bulb. Daylight have 1200LM.

In terms of light efficiency should be okay but you still have old type choke wasting power (some can operate with it there)

Hi guys. Need some help here.

I'm renovating my condo unit right now and have mostly settled on the lights. Got them from Deng Lighting. I'm using narrow-angle eyeballs as my general lighting in most of my rooms (6w 700lm 36°).

However I'm having trouble finding a suitable LED for my balcony and study room. I prefer having eyeballs due to aesthetic reasons and I'm looking for the following:

Balcony - surface mounted
1000-1500lumens with a 36-45° beam angle x2

Study room - recessed
1000-1200lumens with a 36°-45° beam angle x4

Deng/lightcraft don't seem to have any in the specs I want above. Any ideas what other shops are there to get them?