LED drivers and Accessories you want, but don’t exist

As a Buck-Boost, one option would be the TPS63027 usable, maybe up to 2A for UV LEDs.

The more you step down voltage, the less efficient the driver is. So a 2S config for 3-4V LEDs would be better, or 4S with 2 3-4V LEDs in series or one 6V LED.

Agreed, it would be foolish to input 4S and output 1S at 50A. There is no single LED that can handle that so you are better off running multiple LED’s in series. It makes things much simpler and more efficient.

Remember, voltage is easy, you pay no penalty for voltage other then needing to make sure your components can handle it (very easy up to around 30V).

On the other hand you pay BIG penalties for current. A 50A buck driver would be very difficult, I know as I am working on a driver that needs 30A and we ended up needing to split it into 2 separate 15A drivers to get the features we wanted.

I need a 17mm boost driver to run a Nichia 144A at around 3 Amperes from 1 cell.
It would be nice to have a boost driver like that with the option to set the current, like from 3 to 6 Amperes.
Optional e-switch would be nice too.

I haven’t yet seen ‘synchronous’ buck or boost drivers either.
Those are more efficient (iirc)

There is a boost driver floating around using this design and would fit your goals except for the firmware. It uses custom firmware instead of Narsil / Bistro like we are used to.

The firmware is one of the bigger issues. We need good workign firmware for the latest MCU generation then some good base Buck / Boost setups. After that we can combine them to fit whatever we want.

My wish is similar to Jerommel’s, but a 2S input would be nice too, so buck-boost.

Input: 1-2S
Output voltage: 144A or 3x 219B/C, so 5-10 volts
Output: three modes is enough from 100mA to 3A

The Luminus LEDs which I mentioned are rated for a max of 28A. They will probably be able to take a bit more. So 30A is the absolute minimum here to make a driver interesting in this case!
The new Luminus CFT-90 is the one that is really interesting. It is much more efficient compared to older models. It is as bright as an XHP-70, but it’s factory de-domed and the DIE is only 9mm^2, the XHP-70(.2) should be around 14mm^2 when de-domed and 28mm^2 with dome). It also probably doesn’t have the 3D-Die of the Cree LEDs and will probably have a very high luminance (so very high throw with very high lumens). There is nothing on the market that matches it.

Please tell me more about your 30A project. You can PM me if you like.

5s buck driver. I have some black+decker 5s2p 4ah packs I would like to use to drive 12v leds, but can’t find a suitable driver that will accept 20+ volt input. :frowning:

Easy! The German company pcb components offers this. There are different variants. Two for up to 3A LED current:

https://pcb-components.de/led-abwaertswandler-buck-step-down/micro-2800ma-5v-28v-detail.html

https://pcb-components.de/led-abwaertswandler-buck-step-down/black-power-v3-2800ma-3000ma-5-5v-50v-detail.html

and one for up to 11.5A:

https://pcb-components.de/led-abwaertswandler-buck-step-down/ampere-5000ma-oder-9000ma-7v-25v-detail.html

The US company TaskLED also has some: http://www.taskled.com/

quite pricy LED, but like 6000 OTF lumens from 9mm² might be possible, which would even beat a very hard driven XHP35

Interesting, never heard of the Luminus CFT-90. The last gen models were so inefficient I wrote them off. This latest version is still inefficient but it is not that far off of what we drive other LED’s to here.

Still going to be a tough job to make a buck driver for that, it will need to be quite large to fit the components needed, even a 46mm driver could not be big enough for everything depending on what components are used.

The project is kinda floating right now, not gonna say too much till I know if it is going forward or being dropped.

Basically it is a 6s6p input that needs to provide 18V at ~30A output to some LED’s.

Some math can give you an idea of what the results might be.

This maybe?
http://www.international.mtnelectronics.com/index.php?route=product/product&path=67_115&product_id=846
2-4S input.

Luminus LED are 3-4v and use 30A+ current.
Take a look at some of the datasheets, it’s insane.
As with most LEDs you can drive them at even higher currents for more output as long as you give them enough cooling.

Let’s assume one wants to drive it at max allowed Tj (150C)
They rate Vf vs temp up to 120 degrees, let’s use that.
27A (this is the max, not 28) * 3.52 V = 95W.
Thermal resistance between PCB and junction is 0.45 C/W.
Let’s assume 30 degrees max ambient temperature. You need your host to have under 0.8 C/W. So even stock output will not be thermally sustainable in a passively cooled flashlight. Which is not always a problem. :wink:

The LED has a build in thermal resistor, so you can ramp down when it gets too hot
you can do it smart so that the ramp down also calculates the thermal difference to Tj which gets lower with less current

there are no thermally sustainable flashlights in that power range so far, the X9 might get 100W thermally stable

Not with that U.I.
I want all the nice features some of the BLF drivers have ;).

Regarding CFT-90:
When you a driving an LED with 95W you can add a fan. It makes no difference in the runtime in practical terms. The light needs to be big anyhow. You need lots of batteries, a big heatsink, large driver, large reflector or optic (only a thrower makes sense).

Boost driver for xhp and mt-g emitters with firmware adjustment of current limit and pwm for fan speed control so the higher the output the faster the fan spins. Sized for 3p or 4p 18650 or 26650.

I would be fine with a single mode UI for my flashlights tbh… :stuck_out_tongue:

To me 3 modes 10% - 30% - 100% is enough for lights up to 10 Watts.
for more powerful lights an extra ‘lower low’ is a must too.

I maybe look into building a buck-boost driver with the TPS63027, so 2A max output.
Another topic: looking at multiple posts about fans for cooling, I can’t quite get it. Where should the fan get air from to cool the components?