XHP70.2 at full power of 30W through two channels.

XHP70.2 at full power of 30W through two channels.

The idea is simple
Use XHP70.2 in dual channel mode.
In this case, the driver is compact, simple and there is no overheating.

Interesting mcpcb, what are the advantages over single channel driven at 6V?

Advantages in current.
With one channel, driver current 4.8A is needed.
All the drivers that I met are very hot at 4.8A
When you work on 2 channels you need 2.4A current. 2.4A is a lot of good and simple drivers. They are compact and efficient. Therefore, there is no heating.

Now working with XHP70.2 has become much easier.
It is enough to take a cheap driver that issues 2.4A and add a second channel on top.

I'm not understanding. Are you using two separate 2.4A drivers?

Yes, the mcpcb is original and simple

Yes, two separate drivers.
But the control microcontroller is one common.

Wouldn’t it just be better to use a 12V MCPCB instead?

Not.
When powered from 6 …. 12V of two or three lithium cells, the best is 6V version.
If you have 4 lithium power, then the 12V version is better.

Oh it’s a 2 channel buck driver!

That’s very smart IMO.

Yes, you can use modern step-down synchronous drivers with integrated power elements.
And if you need a very cheap way, you can use inexpensive сhinese drivers such as qx9920 and others.

I don’t think I understand the benefit of a 2 channel buck driver. Does this mean it has 2 sets of components like inductor and FET? Is there really a size advantage to using two 2.4A-capable drivers versus one 4.8A-capable driver?

There is a benefit.
Verified
With a current of 2.4 A, inexpensive, small-sized power elements can be used. The load on the elements is distributed evenly. At a current of 4.8A, special measures are needed to remove heat from the power elements, which leads to an increase in size and price.

Try to make a driver for a 4.8A LED.
Then you will understand

Yes - this is definitely a good idea!

the MCPCB you use is pretty useless
with 2 seperate buck circuits you can simply run a normal 6V MCPCB and connect the 2 buck in parallel

if the Buck chips support synchronisation you can 180° phase shift them


MF01 4S—>3S simple connect both outputs in parallel to the MCPCB

Original driver has 4 2S—>6S boost converters in parallel but is still a lot less efficient

One of the less obvious benefits is the fact that the losses are proportional to the current squared. As a result, it is very likely that a pair of 2.4 amp drivers will have smaller losses than a single 4.8 amp driver.
2 x 2.4 x 2.4=11.52
4.8 x 4.8 =23.4
So such a ‘twin’ driver would in theory have only about half the losses of a single larger driver. Less heat, less wasted energy, longer run time.

Well that is assuming two identical circuits with identical resistance components. Of course more large inductors and FETs is better but we don’t have unlimited space.

It sounds like heat dissipation is improved with multiple small components compared with single larger components, possibly because of the higher surface area to volume ratio of the small components.

This driver I see on mountain electronic do 5.5A output as bucking driver in 17mm size!

http://www.mtnelectronics.com/index.php?route=product/product&path=67_115&product_id=554

It say it can take 5-18V input and work for 3, 6 and 12V led.

For heating, I believe usually the led is the main heat element, not the driver, so usually flashlight overheat first because of led not driver?

It’s amazing you post this because I had just recently proposed this thought to someone earlier, and this helps confirm my thought.

It looks like it’s DTP, in which case, not useless.

Thanks for sharing this idea svitlo!

There may be other advantages to a MCPCB like this… for a mounted light, you could make the light “directional” by dimming one channel and brightening the other - like for a stationary vehicle light that still “turns” with the vehicle, or “points” up or down with the terrain… possibly with a cross fader or stacked pot.