H17F - programmable driver with full thermal regulation

I just installed this driver in my S2+ with XP-L HI V2 3D. I love the extensive customizability.

Temperature setpoint is 60C. In high mode (2.9A using all the 7135 chips), the current starts to drop within 20 seconds and is down to 1.5A by around the 1 minute mark.

In turbo mode, I’m getting around 4.5A with a pretty fresh LG D1 cell at around 4.26V open circuit. In turbo mode, the thermal regulation is much less active. It doesn’t really significantly drop the current in the first minute and the flashlight gets much hotter than high mode, of course. Is the regulation behavior different in turbo mode because it is using the FET channel?

It just occurred to me the different behavior could be a result of the heat generated by the linear regulators. In high mode, the regulators are dropping ~0.4V which means they are dissipating ~1.2W at 3A. The FET, with 30mOhms resistance, is dissipating 0.6W at 4.5A. Maybe the driver is actually getting hotter in high mode than in turbo mode because of this local heat production?

EasyB, in your case the 4.35V cell may not be the best choice for efficiency at the lower levels. It is obviously heating the driver quite a bit.

Most higher performance cells will have similar behavior at 3A. For example the LG D1 discharge curve nearly coincides with the Samsung 30Q and Sony VTC5 at 3A for the first half of the discharge.

It is a compromise between linear driver heating and being able to stay in 3A regulation for as long as possible. Ideally, there would be a cell that had a completely flat discharge curve at 3.6V at 3A, to be most efficient. I chose the LG D1 for this flashlight because it provides the longest time in 3A regulation; the discharge curve levels out near the end more than most other cells, so you get more useful power out of it.

Just checked my S3 and M2 both at level 22. Temp at level 5. LG HG2.

S3 2.86 amps at start climbs to 2.95 in 10 seconds. About 50 seconds starts to drop.

M2 3.03 amps at start. Stayed there for over 2 minutes before I gave up.

I think this could be a host issue.

S3 is the shelf one and I feel the heat almost instantly.

M2 also shelf design , just barely warm after 2 minutes.

Thanks for your data. What about in turbo mode? If linear regulator heat is contributing the regulation, battery state of charge would also be important.

I just did a more careful timing of my light regulation. From room temperature, 2.93A. After 30 seconds starts to drop. By one minute it was at 2A.

Topping off my LG’s Will repeat Level 22 and Level 24 in both host.

Repeated level 22 with fresh laptop pulls. Set temp to 60c

S3 2.9 at start. 2 minutes dropping begins. 2.5minutes 2.5amps. 3 minutes 1.9 amps. Light is very hot.

M2 3.03 for 4 minutes without dropping. My meter auto offed. Light is warm.

Turbo Mode LG HG2 . Temp at 60c

S3 3.8amps. 2.5 minutes drop starts. 3.5 minutes 2.6 amps and dropping fast. Really Hot.

M2 5.4 amps. 2.5 minutes drop starts. 3.5 minutes 3.8 amps dropping slowly. Hot.

I don’t know why I am getting different amps on turbo. Both have spring bypass. Connections are clean. Could it be XPL HI in the M2 vrs Dedomed XML-2 in S3 ???

HMM,
Looks like the S3 on Turbo last 30 seconds longer than on level 22 before reaching temp.

Lights were tested standing on there heads. with hands partially cupping around while I held the leads to the tail. With better cooling level 22 might not be an issue on the S3 host. Going to guess at 2-2.5 minutes is when the heat rush reaches the driver on both host…

Thanks again for the data. So it seems to me like the heat produced by the linear regulators is significantly contributing to the temperature of the driver, causing it to step down quicker in high mode than in FET only mode.

My S2+ seems to step down quicker than your S3. Part of this could be host related, but I imagine there is also some variability in the temperature sensors.

How do you like the M2? There seems to be a good amount more thermal mass based on your measurements. How is the beam compared to the S3?

A problem suddenly appeared today. The light will randomly flicker and not reach full brightness in all modes using all 8 of the 7135 chips (modes 17-22). Using the FET channel, there is no problem. Also, modes using 1 7135 chip (first 16 brightness modes) are fine. It is not related to the thermal regulation because I’ve changed the temperature setpoint all around and it makes no difference.

Could one of the 7135 chip connections be bad and cause this behavior?

I had bought another H17F driver to use in another build, so I stuck this extra one in my S2+. I will see what mtnelectronics says about the malfunctioning driver.

Just to expand on this idea some more: with the LG D1 cell at about 3.9V OC, the current was just under regulation at about 2.8A in mode 22. The current was very close to the regulated value of 2.93A, but the regulators did not have to burn off any extra heat, so the driver temperature stayed lower and thermal regulation did not happen in the first 2 minutes. Then when the cell was charged to 4.15V OC, thermal regulation again happened in about 30 seconds in mode 22.

At close to full charge, a typical high performance cell will provide 3A at around 4V. The 7135 chips then must dissipate 0.45V*3A=1.35W, but this is only 0.17W per chip. This is within specs for the 7135; the data sheet suggests that at dissipation powers above 0.7W, additional heat sinking is required to regulate the junction temperature below 120C.

So the question is: because the temperature sensor is on the driver and not closer to the emitter, is the thermal regulation stepping down the current too much too soon? Maybe so, but it should only be a problem when the cell is close to full charge. Within several minutes at 3A most cells’ voltage will drop much closer to the Vf of the emitter and the regulators won’t have to dissipate as much heat. Then the driver temperature should be much closer to the pill temperature.

I can’t really think of a better way to do it other than have a separate temperature sensor much closer, thermally, to the emitter. What about an IR thermometer on the top of the driver aimed at the bottom of the pill? :slight_smile:

I did some testing of the low voltage protection and voltage indicator function. The low voltage protection behaves as the manual says, but the cutoff voltage for mine was 2.8V instead of 3.0V as the manual says. The current dropped, at 2.8V, until it reached 1.4mA, then stayed at that value for many seconds until I stopped monitoring.

Voltage indicator:
10 blinks: 3.86V - 4.00V
9 blinks: 3.70V - 3.85V
8 blinks: 3.60V - 3.70V
7 blinks: 3.44V - 3.60V
6 blinks: 3.30V - 3.43V
5 blinks: 3.19V - 3.30V
4 blinks: 3.08V - 3.19V
3 blinks: 3.00V - 3.08V

It has the capability to blink more than 10 and fewer than 3, these are just the voltage levels I measured closely. This pattern is pretty close to each blink corresponding to 0.1V above 2.8V.

Having the sensor on the driver is an obvious compromise, but one I will take for the majority of smaller lights. I have done them on the pill or body thermal shelf before, and it is not fun wiring those things up inside of a small pill.

I just put this driver into a copper sinner I sold for a friend. Outstanding. I loved the lucidrv drivers I was using before but this is a nice step up.

Insane moonlight mode and direct drive. Double tap mode. Just amazing. Now can we get something in 15mm?

Build a C8 with the H17F, it’s simply perfect!

Based on the double tap, I deleted turbo from the mode sequence and now I have moon>low>mid (3mA-380mA-1520mA), and double tap to access turbo. Then I set group B to a dummy group and only has low-high (380mA-2150mA) with PID set to 50°C.

I just installed this driver in my triple xpl BLF X6. I’m loving it, its pretty amazing.

I went with low 4.2mA, mid 380mA, high 3040mA, and double tap for even more turbo.

I’m surprised the little fet works so well. I haven’t taken amp readings but the flashlight gets just as bright if not brighter than the MTN-17DDm I just took out and that fet is much larger.

I also lowered the temperature from 60C default to 50C, and turned off memory.

I haven’t decided what to do with the second mode group yet.

This is now my favorite clicky driver.

where is the shop to this?

or do i need to shoot a pm ?

I imagine DrJones is still selling them, but I don't know for sure. We also sell them.

I ran a thread search and it didn’t come up: can this driver be used with a momentary switch? (E-switch)

That would be very nice! But unfortunately I don’t think it does.