Hi all,

I am a compulsive DIY’er. Took electronics in HS many years ago.

My wife has solar charging LED mushroom lights. One light failed, wired in parallel. I purchased a 5mm 20mA white light and soldered it in place. Colors are a lot different. Old light is a yellowish white light and new one is a blueish white. I don’t know the specs on original lights.

the solar panel has 1 .2 v 1600 mAH battery and output is 2.7v. I don’t know how to measure the current.

Q how do I get a closer match in light color?

 

Welcome to AAC!

It might have something to do with the diode forward voltages and the current balance between diodes. Try experimenting with inserting various values of resistors in series with the blueish LED.

 

An LED called “warm white” would be more yellow. Don’t know how to match it without just trying different ones.

 

Welcome to AAC!

Q how do I get a closer match in light color?

Replace the old LED so both will be the same type.

 

The color of LED light is mainly determined by the LED material composition (below) and is only slightly affected by its current level, so to get a different color, you need a different LED.

 

Look for low Kelvin, something around 2,000- 2,500 Kelvin.
You most likely bought ~5k Kelvin!
Look at a LED kelvin chart and it will give you an idea.

 

If you can measure the forward voltage of LED you want to duplicate, that will tell you fairly closely its color temperature.

 

If you can measure the forward voltage of LED you want to duplicate, that will tell you fairly closely its color temperature.

Don’t think so, I think the color temperature is controlled by the phosphors that make a blue LED white.

 

To have that more yellow glow find the "warm white" lower color temperature LEDs. Some folks believe that they are somehow healthier. Certainly they are less conducive towards greater productivity.

 

To have that more yellow glow find the "warm white" lower color temperature LEDs.

The Kelvin No will tell you closely what the emission is like, the yellow light that simulates the old filament lamp, is around 2000-2500 kelvin.

 

The warm white LEDs often have a yellower phosphor than the cold whites. Try harvesting LEDs from dollar store flashlights if you don't have enough e-waste lying around to salvage from.

 

The warm white LEDs often have a yellower phosphor than the cold whites. Try harvesting LEDs from dollar store flashlights if you don't have enough e-waste lying around to salvage from.

Those are likely to be bluer since the blue-white ones are more efficient.

 

The bottom line to this discussion is that to get it right the first try you need to purchase "white" LEDs listed to have that 2000 degree color temperature. They may also be called "warm white." LEDs. Unfortunately some sources do not have any information except price and shipping weight. I suggest avoiding them.

 

Thanks to all. Your advice and suggestions are greatly appreciated.