100Mcd LEP - Laser Phosphor Wheel

Useful ideas for your controller.

I would suggest adding circuitry for charging, including balancing and capacity-left option. Or what I like: Runtime left on current level. Some buttons for special functions like momentary-full-power is nice. And programming interface accessible without having to open the lamp: Once you write your own software, there will always be improvement ideas, and you will want to program oftenly in the first time....

Yep, I am using an IR RPM sensor directly reading the RPM of the wheel.

What would be some ways to monitor/measure capacity? Are there BMS systems that can output that data? Since I am running these cells at 70% of their maximum continuous discharge rating, they would voltage sag quite a bit so measuring voltage is not optimal.
I could put a current sensor but it seems like it would not remember capacity after disconnecting power.
My programmer will be using an arduino, so I just only need to edit certain variables according to my liking through USB.

if you used it in cold temps [winter], could it do even more?

how bright are all those candelas, compared to the sun at noon in summer?

wle

Regarding battery capacity: On my 1500W build I implemented the following calibration procedure:

  • Battery is fully charged
  • A complete discharge is performed
  • During this discharge, once every 30 seconds the lamp is driven to no-load, mid-load, heavy-load
  • Voltage value is stored for all three load cases, so three values per 30 seconds
  • Once battery reaches end voltage (3V per cell), it is further stored how long total discharge did take
  • Now the voltage level corresponding to certain battery fill grades can be calculated
  • Internal battery resistance can be calculated from the voltage drop between the load steps
  • During operation I then always look up the no-load voltage curve. Depending on lamp power level I then add a value calculated form battery current and internal battery resistance
  • This work pretty good, when ramping lamp power up and down, my capacity keeps +-5% accurate

Knowing the battery capacity in mAh or Wh it is possible to use a hall current sensor and simply integrate to find the drained capacity %.
That’s how all these cheap battery capacity monitors work.
https://www.amazon.ca/Yeeco-Voltmeter-Multimeter-Capacity-Detector/dp/B073W6453F

These are all great ideas!

It seems with an integrated battery, by far the cheapest and immediately effective option would be to map the voltage profiles.
I will use this method once I have a permanent pack.

If I used capacity tracking, what would be some effective ideas to store the remaining capacity value? The auxiliary pack I use to power the controller and other components will be removed since they are my general purpose batteries. Based on my limited knowledge, If there is no continual power supply, we will need the controller to write and save to flash the capacity values periodically. Due to limited life cycle of flash writes, it may not be the best option.

Why do you plan to use a separate battery pack for the controller? Isn't it simpler to have that also derived from one main battery?

I also thought about doing an integration over current and voltage going in and out of the battery, but at >100A current sensing would have consumed too much space, and space is something I had nothing left....

Further, there is the effect of slow battery discharge during non-usage. Getting that not into integration would cause error; and a lamp can sometime lay around some days/weeks without usage.

So with that in background, I found the calibrated voltage method being suited for this application.

By the way, if you have an application needing permanent, non-volatile logging, using an MRAM can be an option.

Can be accessed like SRAM, but keeps content after power loss.

I’ve wondered if it would be possible to make a wide angle high intensity thrower by using something like phosphor wheel and a light directing. My line of thinking is like taking a thrower and scanning around very quickly. If we take a crt monitor or possibly and more applicable, DLP systems as inspiration. Highly directed light hits the sweet spot in the reflector or lens system but can also be scanned to other areas in the way a theater projector creates a seamless image.

Yeah that’s very possible, if you take a small actuated mirror like the ones inside laser scanners (used in clubs or festivals) you can make the laser move very rapidly in a small circle, which effectively increases the light emitting area on the phosphor it hits, making a wider beam.

The beam angle would only change by a couple degrees though, since the area you can cover would depend on the speed of the scanning as well as the phosphorescence decay time of the phosphor.

I have an update on the schematic.
Originally planned for 1 controller, but we quickly used up all the pins so we moved to two controllers.

I am not quite sure why I wanted separate battery packs. It does seem like unnecessary complexity. However, It just feels cooler to have it separate haha.
Something with 50V stepping down to 12~5V didn’t sit right with me.

We ended up deciding to use a current meter and the EEPROM to store Wh consumed. Also have a mini encoder switch to adjust starting Wh and reset tracked Wh.
The designer said even with limited writes of the EEPROM, it should be sufficient for this prototype while considering the complexity involved.

_
I thought If I added an actuator to the parabolic mirror, I could achieve flood mode too! I was very wrong.
The result is EXACTLY like Robin Dobbie’s GIF. There is no light at the center and just a halo ring of light getting larger as I zoom out. haha pretty garbage flood.

It seems some kind of lens needed in the system to have a useful flood mode.

I guess the real question is… When are these for sale? :smiling_imp:

Yeah, defocusing a reflector doesn’t work because the points on the parabola are at different distances from the LED.
This means that the center part defocuses a lot faster than the outer part because it is closer, which causes a donut shaped light.
With a lens this is not as extreme, since the points are not at such huge different distances, but it still does happen.
.
Creating a larger spot without a donut hole involves changing the diameter of the light source (aka the lit spot on the phosphor)
This can be done by defocusing the lasers, vibrating or moving them very quickly, or using a precollimator lens to magnify the source (if using an LED)

Any new progress to report? Looking forward to seeing this in action.

Yes, me too! I have a new Thor Lumintop LEP on the way. I’d love to have an LEP the size of my Imalent MS18

I am patiently waiting for my electronics engineer to work out all the coding, communications, bunch of sensors, and laser drivers.

_
There are some updates regarding the phosphor wheel.
Here is some preliminary information:
100% of the industry uses phosphor wheels to obtain Red Green Blue for projectors. Selectively mixing R, G, and B will grant you almost all colors.
Blue lasers are extremely cost effective. They are high power, low cost, beam can be focused into much smaller spot compared to LEDs giving a high intensity.
Red and Green lasers are very expensive and has much lower power output.
Therefore, it would not be cost effective to use Blue lasers, Red lasers, and Green lasers in one projector.

In order to create a cost-effective product, the industry only sticks with using Blue lasers. The component that solves this issue are Phosphor Wheels. PW convert the blue laser light into a large spectrum of light ranging from yellow to red.
By using a dichroic filter, it is possible to split this yellowish light into separate green and red channels. Now that we have Blue (from laser) Green and Red (from PW) we have the necessary colors to produce a projector.

Here are some examples:


However,
In my case however, I do NOT need RGB channels. I am NOT making a projector! I just want a flash light.
The design is simple, focus blue light onto phosphor wheel, and then collect all the light into a beam!

The result would be a yellowish tint. Not very pleasing to look at.

For my case, there are two solutions.

  1. Produce a new phosphor that outputs white light. (similar to the ones used on LEP flashlights)
  2. Mix blue light into the system to obtain white light.

Solution 1: The industry is currently NOT focused on making white phosphor wheels. There are no buyers. Everyone is only buying Yellow phosphors. If I were to make PWs with white phosphor, it would require new tooling costing of up to 20,000USD+

Solution 2: As I have mentioned before, the yellowish light produced has an even amount of green and red. Once I add blue, it will result in white light! There are phosphor wheels that have unique surfaces on them. Some have a transparent sections. Some have different colors. Some have diffusers to reduce laser speckle. And lastly, some have a reflective diffuser.
If I were to add a section of reflective diffuser, I would directly diffuse the blue laser directly into my output light so it becomes white.
The fixture costs to arrange this would be below 5000USD

Both solutions have a proportionally high cost, so I will stick with the current yellow phosphor and make a decision later.


Thanks for the update, I appreciate you taking the time to share, I’ve learned a lot from reading all that you have shared in this thread. I dont have the time or knowledge for a project like this but at least I can share in the enjoyment watching you put it together.

If you can make this work and get 100 Mcd, you can probably sell these for a few thousand dollars easily. It sounds far more powerful than the new Acebeam W50 and the Peakbeam

It also will cost thousands of dollars to build, so profit margin = 0 :frowning:

The Acebeam W50 costs $2,300 for 1200 lumens / 4 Mcd

For 25x the beam intensity, who knows how much you could charge. Military, coast guard, or people with more money than brains

My plan is to post the BOM and 3d files for public gain. Trying to make any money from this project would result in its certain demise. I’m happy to give information for free anyways.

The best case scenario would maybe find a manufacturer who is willing to arrange a group buy haha.
Theoretically speaking, it is unbelievably cheap for something of this caliber considering it was designed without the need of fixtures, toolings, and molds. Everything is flat sheet cut. There are no CNC metal parts. The things that are more complex 3D shapes can be 3d printed without supports. All the other components (radiator, pump, fan, battery) are consumer grad;e which are already competitively priced.

The only major component that needs special attention is the Parabolic reflector. I bought one with a customized rectangular hole cut for 400USD. It might go down to 300USD if there is a group purchase. The process to make a metal reflector is very slow and labor intensive. This is still very high considering it is just a piece of metal.

The perfect solution would be a parabolic reflector made of glass. The manufacturing process of glass reflectors automatically results in smooth and accurate surfaces every time. Very cheap too!

~50USD each but the mold and fixture costs would be around 4000USD.