Buck and Boost Drivers, Testing, Modding, and Discussion (Pic Heavy)

That looks like a neat design, but it’s dynamo powered? I guess it runs off the turning bike wheel? Seems odd.

Have you seen Lumintops new bike light, the B01 It’s a similar lens design, but cheaper and uses a 21700 battery. Plus it’s USB rechargeable so you should be able to plug in a power bank to greatly extend run time. Your spending a small fortune on modding that IQ-XE. It might be time to cut your losses.

The IQ-XE is entirely different league when it comes to a most lux at distance with distinct cutoff line for least lux up onto oncoming. The best comparison is the Lupine SL with broader and more even coverage, which many prefer over IQ-XE, but not me. We have very bad roads here and I need to see those potholes well ahead of time and the IQ-XE is the most efficient at putting lux right at the cutoff line directly ahead. The IQ-X is the dynamo version and IQ-XE is Ebike version. Had both. Same except for internal drivers. Dynamo version is cheaper, so it’s better for driver modding. When modding for higher output, also best to bond the LED assembly to the housing for better cooling of the LED. BTW, IQ-XE is already more than enough for just about anyone, but I can never turn down opportunity for improvement, and this mod does wonders.

I’m building the battery pack with regulated DC input for expansion and charging, and 5v DC output for phone charging while on the go. I wouldn’t venture OT but this is your thread, so I’m glad to expand.

I’ve messed with a lot of projector retrofits with hid when they started to be more common 15 years ago and recently started studying led versions of projector and even reflector housings. I love projectors for their sweet cutoff lines and very usable light on the ground.

These 90° led/reflector designs are still pretty new to me. I see them popping up here and there. Do you think their beam shape beats a projector housing?

I have seen these 90° led/reflector designs (do they have a specific name?) in aftermarket fog lights. I wonder if the design will be adapted into a OEM car headlight design soon.

Automotive is easy because efficiency isn’t detrimental. So simply blocking of the top half of the light works, and has inherent high beam built right into the same unit. European restrictions on bicycle lights has driven the market to create new ways to illuminate only the lower half without losing efficiency under small battery operation, and without need for high beam.

For what it accomplishes, I think the 90° design is genious. But because the automotive projector design is so simple while having inherent high beam, I don’t think it’s going to be replaced by the more efficient 90° designs soon, but it’s possible. Saving a few watts in automotive probably makes less difference than having a bug on the windshield.

However, you may find the Lupine SL interesting, as it’s an implementation of the 90° design in a projector configuration. That’s what makes it a much more pleasing beam pattern than the IQ-XE, but also what makes it have less peak lux.

Doh! :person_facepalming: I forgot these new 90° designs can’t change to create a high beam. Still, a lot of cars use dual bulbs per side, one projector for low and typically a reflector for high beam. So still possible.

Maybe it’s just cost. I know projectors can have the cutoff line easily changed for left or right hand drive countries as well as special shapes. You just change the stamped metal shield. These new 90° designs might require more extensive modification (more :money_mouth_face: to adjust the cutoff line.

Automotive OEM’s have not really embraced led headlights anyway. There are a few ultra expensive led designs out there (mainly prototype designs), but I bet projectors are just way cheaper.

Those 90° optics are new to me. I’m not sure I understand what exactly is going on in them. Has anyone seen some writup or a schematic on them?

Many years ago I was following the first experimenter of this design on mtbr.com (who doesn’t get the deserved credit imo). He was using portions of a large reflector to piece together the concept, somewhat crude but ingenious and it worked. Soon after, Edelux came out with the first commercial light with a reflector created specifically for the design, followed by many others. The first Edelux angled the LED at 45-degrees. Over the years there were many improved generations of these lights with the current IQ-X using 90-degrees, in which a convex combined with a reflector utilizes the light more efficiently.

Edelux Design

IQ-X / IQ-XE (Google-Translated Version)
The convex lens and double “series” integrated Oslon LED seen in last photo of post. The OSLON Black Flat KW H2L531.TE

Thank you, that’s interesting :slight_smile: . I’ve seen Endermann calling that off-axis parabolic reflector.
It clearly works well with headlamp LEDs which are often sold pre-mounted as several-in-a-row configurations. That seems to be what IQ-X is using.
Any more info of Lupine SL A projection optics?

ADDED: Though I still don’t understand that IQ-X convex lens.
Is it used together with the reflector?

See the Lupine SL here
The side view is clear it’s a convex lens that refracts all of the output from ceiling-mounted LEDs.

Yes, The IQ-X convex lens only refracts the forward-emitted output, and rearward-emitted output is reflected off the reflector.

The Philips Saferide was the first to use multiple LEDs early on. Here’s some good history.

Edit: Note that the IQ-XE consumes less than half the watts of the Lupine SL, but produces more lux at the cutoff line. I do very long night rides on bad roads, so in my case, the IQ-XE is much more proficient. The Lupine SL puts a lot of light to the sides, which is especially nice for off road. But my friends and I realized we like light only on the roadway directly ahead and the least amount of light spill, because spill light kills the ambience of the ride. Just a preference.

With aftermarket LEDs that take the place of a filament bulb in a reflector based housing, they put 3 or 4 chips next to each other to simulate the size and shape of the filament. The reflector is specially designed to focus light from that grain of rice size light source.

With the new 90* reflector designs, they are creating a string of light for other reasons. They can probably use any shape they want, but the thin string probably helps give a wide view with sharp cutoff. They are starting with a clean design as opposed to adapting to an existing reflector.

We don’t have strict bicycle headlight laws in the US so I never even looked into the market. Here people just strap any old flashlight to their bike and blind everyone. Lol.

We might be getting a bit too off topic now.

Double LEDs create horizontal off axis, which spreads the beam pattern horizontally. Bringing this back around, you can see the need this creates for drivers like the H1-A.

They just need to wire the leds in parallel.

Not sure if it’s right thread to ask. but is there any way to know which resistor is responsible for output current in below driver -

this is a from a 13w motorcycle headlight, designed for osram black flat leds (looks like it). output current is 1.5amp. but i want to increase it to 2.5-3amp and replace led to whiteflat.

Sorry to skip over your question slopegatri70, but JasonWW the LEDs are series embedded into the Oslon package.

@slopegatri70:
LED_Low: R4 and R5
LED_High: R9 and R10

Nice, but how did you figure that out ? and what should be replacing resistor value for 3amp output ?

thanks.

Yes, that’s why I said “they”. I was refering to Oslon. In the the way Cree released an all parallel wired 3 volt xhp50.2, Oslon needs to release a parallel wired version running at 3 volts.

Granted, it’s not a very helpful post because it’s completely out of our hands. Does Oslon make a parallel version of that led package? I have no idea what leds they make.

I looked at the circuit and my guess were the same resistors. Look at the values. Those are the only ones with a really low value, 0.36 ohm. That is typical for a sense resistor. Plus the package size is about right.

The big ones labeled 2000 (200 ohm) are too high a value plus are probably related to the power input section (middle of the board). They are also right next to the main input wires. Since it’s from a motorcycle I assume it’s a Buck driver so you need the power input section to take the 11v-15v input and smooth it out, get rid of the spikes and ripple. The generator/alternator on a car or bike is creating AC current on 3 output wires (some small bikes might use 2 wires) which then goes to a rectifier bridge turning it into a chopped up DC voltage then to a voltage regulator. Plus voltage can vary with engine rpm. I’m guessing this led driver needs a cleaner, smoother input. I only see resistors and diodes so not much is happening here, just smoothing out as far as I can tell.

Then the input voltage gets sent to the driver side you need with High on one side and Low on the other. The 2 driver sides looks almost identical in design and components. Same inductors, same IC chips.

I guess input voltage still varies up and down and the drivers just compensate so they put out steady voltage and current to the leds.

This is my guess and I’m just learning these things. Hopefully Schoki or another engineer here can tell us for sure.


I don’t know if there is a way to calculate the results of a new sense resistor. You might just have to experiment. R9 and R10 look to be in parallel, same for R4 and R5. This means the pair are creating 0.180 ohms. If you replace one of the R360 for an R250 the total resistance goes down to 0.15 ohm. Try a small change like that with the new led and see what you get.

Keep in mind that driver may not be designed to handle much more current than it does. It’s possible you could damage it. So don’t make big changes.

Better yet, listen to Shocki instead of me. Lol

AFAIK the Oslon was developed for “beam shaping”, I don’t think come in parallel. But the IQ-X embeds the Oslon so a parallel OSLON couldn’t be retrofitted anyhow. I looked into this long and hard because 3v drivers are so much more common. Also the Oslon is the highest lumen density of all LEDs, I do believe.

The manufacturer employed SK26A which is a 2A60V diode for this buck driver. I guess that the drive current is around 1A to 1.5A. You just replace the sense resisters to boost the current to 3A may not be possible. The ability of the inductor and the driving IC are also to take into consideration.