Texas Avenger "TA" Driver series - Triple channel + Bistro or Narsil + Clicky or E-switch - The Ultimate open source driver!

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The Miller wrote:
Actual PCB designing seems way out of my league, again a very intimidating thing for me still struggling with basic soldering.

Yeah, that’s what I thought, too. I followed a tutorial for Eagle and realized it wasn’t really all that hard. You can get Diptrace for free and watch a couple Youtube videos, and surely you can at least learn enough to extend the outer boundary of the driver a bit. You don’t even have to move any of the components! Come on! I tried it, you should too! Party

As for basic soldering, I’m beginning to think I’ll never get it right. But, with tips I picked up here (search bar helps) and a little practice, I can at least get stuff together usually. Silly

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The Miller wrote:
Is it possible to have this in 38,5mm as well?

I would love to have Narsil on my to be modded Courui with planned SST 90.
And well I prefer a driver that fits nice in rge light instead of using the default driver just for let power go through, I have the idea that a neatly fitting driver can pass heat of the components to the housing and is thus better.

Like was said the source files for all the drivers are included in the OSHpark links for anyone that wants to custom build a driver.

That said I have been debating making one of these for my own DO1. It will need a bit of custom work for the DO1 to clear the battery ring but that should not be too much trouble. Might move the 7135’s to the top side since there is a lot of extra room.

I am waiting to see what happens with Narsil and the R1/R2 before I make any further changes to the drivers. if we can ditch the voltage divider then I will do that on the drivers along with a few other changes.

It would allow for a 3rd 7135 channel in theory as well, which would be nice, or it could be used for an indicator LED. Been thinking about ways to make it optional on the drivers with a resistor if that comes to pass.

I also want to get the 2s/4s SRK/Q8 driver setup as well, in fact I could just shrink the Q8 design once I have it for the DO1 come to think of it.

So basically, yeah I bet I will make a driver for the DO1 at some point after I get the Q8 and other drivers done.

If anyone else have a special sized driver they need/want/know about, please do post here. I really am wanting to create a lineup of drivers to come everything in a single design. Standardization is good.

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Oh boy, no pressure... smile I do want LVP without parts too though, still not started yet frown.

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Yeah, I have a D01 that could use one of these, but I’m in no hurry… yet!

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Tom E wrote:

Oh boy, no pressure… smile I do want LVP without parts too though, still not started yet frown.

LOL, no pressure indeed. I don’t have time at the moment to work on the drivers anyways Wink

But also for a clicky only driver I am very happy with the current setup and honestly don’t think any changes are needed, except that ditching R1/R2 would be cleaner and less cramped.

So really the changes are mostly for E-switch setups, in which case I figure I might as well wait till the firmware is done to design the drivers around it. Come to think of it, without R1/R2 i just might have enough room for a 209mil SOIC8 pad, although it would not allow me to spread the rest of the design any.

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heheh no rush here too, preparing for the darker months here Smile

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Ahhh, k, I'm confused about the 46 mm SRK driver in the OP. Since DavidEF mentioned it over in the Q8 thread, I looked at it. I don't see any LDO support. If it's designed for 2S or 4S use in an SRK, you need an LDO in my opinion. I don't see zener support as well, but zener is not recommended for e-switch lights since the parasitic drain is considerable.

Am I missing something I don't understand, or have not read? Didn't go thru the entire thread.

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Tom E wrote:

Ahhh, k, I’m confused about the 46 mm SRK driver in the OP. Since DavidEF mentioned it over in the Q8 thread, I looked at it. I don’t see any LDO support. If it’s designed for 2S or 4S use in an SRK, you need an LDO in my opinion. I don’t see zener support as well, but zener is not recommended for e-switch lights since the parasitic drain is considerable.


Am I missing something I don’t understand, or have not read? Didn’t go thru the entire thread.


The driver GND ring is connected to the Batt- of the first cell through the host, to ensure there is always 1S voltage to the MCU, even when using a 2S2P or 4S1P cell arrangement. Therefore, no zener or LDO will ever be needed. Wink
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DavidEF wrote:
The driver GND ring is connected to the Batt- of the first cell through the host, to ensure there is always 1S voltage to the MCU, even when using a 2S2P or 4S1P cell arrangement. Therefore, no zener or LDO will ever be needed. Wink

What he said, this eliminates the need for either zener or LDO since it only ever sees 1s voltage at the MCU. The only thing that sees the series voltage is the FET & 7135’s.

I think this is far simpler then using an LDO

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Now I'm more confused... What about Batt+?

I would think you need one Batt- and Batt+ going to the MCU, and full 2S or 4S of Batt- and Batt+ going to the LED(s)? For example, for XHP-50's (2S) or XHP-35's (4S). DC Voltage is all about potential difference between two sources.

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Tom E wrote:

Now I’m more confused… What about Batt+?


I would think you need one Batt- and Batt+ going to the MCU, and full 2S or 4S of Batt- and Batt+ going to the LED(s)?

It is outside the box for sure compared to what we usually do around here but actually very simple.

If you look at the board here you can start to see what I am doing:


Basically, you have 4 pads on the bottom of the driver + the ground ring. So 5 contact points.

The pad with the TA on it is the 4s positive contact.

The pad with the line of vias at the bottom of it is the batt negative.

The other 2 pads are simply there to connect the cells in either 2s2p or 4s and connect to nothing on the top side.

Lastly you have the ground ring like we are used to. It connects like usual to the flashlight body.

The key to this is how you setup the tail PCB. In this case in addition to properly setting up the tail PCB for either 4s or 2s2p you will simply connect the 1st cell V- (the one with the positive contact on the TA pad) to the flashlight body. This gives you a normal 1s ground to the flashlight body and thus to the ground ring of the driver.

The rest of the 4s setup is unaffected by this and goes directly to the ground pad that feeds the FET and 7135’s.

So the end result is that the ground ring sees 1s voltage while the FET/7135’s/LED sees 4s voltage.

All of the electrical components are grounded to the single cell via the ground ring.

Now obviously the above driver is not ready for use, the pinout needs to be changed and I want to redo it to look better but the design should work.

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Sorry, still don't understand. Can you tell me what voltage/connection is on the GRND pin #4, and what is going to the VCC pin #8? The difference needs to be 1S, and I dunno what is going into VCC compared to GRND. That's all that matters to run the MCU properly. 

Also I don't understand in a 4S configuration how you could possibly get one of those cells to peal off just it's 1S voltage?

From the pics above, I can't see any connection between those 4 pads on the bottom side of the driver? Are they supposed to be connected to complete the 4S configuration?

Sorry - this is why I didn't look into this much -- I just don't get it - something basic I'm not understanding I guess...

 

Hhmmm, Think'n in a 4S configuration for example, you could peel off the 3S output of Batt+ for your GRND,  then the 4S total output would be your VCC? Is that what you are doing? Because then, the difference is a true 1S - doesn't have to be negaitve, just the difference between 3S and 4S can run the MCU?

 

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Tom E wrote:

Sorry, still don’t understand. Can you tell me what voltage/connection is on the GRND pin #4, and what is going to the VCC pin #8? The difference needs to be 1S, and I dunno what is going into VCC compared to GRND. That’s all that matters to run the MCU properly. 


Also I don’t understand in a 4S configuration how you could possibly get one of those cells to peal off just it’s 1S voltage?


From the pics above, I can’t see any connection between those 4 pads on the bottom side of the driver? Are they supposed to be connected to complete the 4S configuration?


Sorry – this is why I didn’t look into this much — I just don’t get it – something basic I’m not understanding I guess…


 

Yes, like it says on the silk screen you need to bridge the pads according to the cell setup you want, 2s, or 4s.

The voltage the MCU sees is 4.2v across VCC to ground. It is connected to only 1 cell.

This is possible because with a 4s setup all the power runs through the cells and never needs to enter the body of the flashlight (part of why big manufacturers prefer series setups). So since the body of the flashlight would not be connected to ground I am simply using that as a free contact point to the tail of the light.

By connecting the 1st cell in the series ground to the flashlight body the body of the light sees 4.2v to V+ (the TA pad).

The only thing that sees the 4s voltage is the ground pad (with the line of vias).

So basically it is a normal SRK setup far as the MCU is concerned, the positive is on bottom of the driver and the ground comes through the flashlight body.

The FET on the other hand sees the end of the cell series ground, so it has a full 16.8V if you check it to V+.

It is just like a series cell pack from a laptop or anything else. You can take a voltage reading across the whole pack or you can read each cell individually. This is the same way that balance chargers work.

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Tom E wrote:

Hhmmm, Think’n in a 4S configuration for example, you could peel off the 3S output of Batt+ for your GRND,  then the 4S total output would be your VCC? Is that what you are doing? Because then, the difference is a true 1S – doesn’t have to be negaitve, just the difference between 3S and 4S can run the MCU?


 

Kinda, it is hard to explain and understand this in words lol. It sounds like you are saying the opposite of what I am doing basically.

I use the cell that connects the positive to the TA pad as the one to power the MCU AND LED as it is better to have ground running through the light then positive. So the other side of that cell (which is ground) connects to the body of the light AND to the rest of the 4s series. The body ground then connects to the MCU to give it a 1s voltage across it.

The other 3 cells keep going in series like normal and ground to the pad with the line of vias which connect ONLY to the FET and 7135. Thus giving them a full 4s voltage across them to positive.

So I am really peeling off 1s and letting the other 3s go to the LED.

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So, if I understand this for a 4S setup, 3S is going into GRND and 4S is going into VCC? The 3S is from the ground ring, and 4S is on the TA pad. That should work. Is this correct?

 

1S is the potential difference. I think if you take 4 cells in series, connect/measure between the 1st cell and 2nd, (1st cell has the batt+ exposed), you are actually at 3S+, not 1S negative.

Oopsie - we keep crossing posts, me, with my editing...

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Chuckle, chuckle… I’m with ya tom, this is hard to see. TA, what about a diagram?

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LightRider wrote:
Chuckle, chuckle… I’m with ya tom, this is hard to see. TA, what about a diagram?

I started to do that but could not figure out how to explain it, I will give it another go, be it a bit crude.

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Maybe a picture would help? This is how I understand it, I don’t know why it wouldn’t work, though I am still skeptical for some reason. (and technically this isn’t totally correct, obviously the LEDs go through the FET to get to the Batt-, but by “Driver” I mean “MCU”)

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pilotdog68 wrote:
Maybe a picture would help? This is how I understand it, I don’t know why it wouldn’t work, though I am still skeptical for some reason. (and technically this isn’t totally correct, obviously the LEDs go through the FET to get to the Batt-, but by “Driver” I mean “MCU”)

Yep, that is it, Same thing I just made up lol:

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To me, this is much clearer, but I understood it in the last post this way before the pic - sorry.

Now, isn't this 3S+ for GRND, 4S+ for VCC? So 3S+ is going through the body?

Btw, that pic is exactly what I pictured in my head, finally... smile My head is a bit thick today, so tuff to get thru.

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Tom E wrote:

To me, this is much clearer, but I understood it in the last post this way before the pic – sorry.


Now, isn’t this 3S+ for GRND, 4S+ for VCC? So 3S+ is going through the body?


Btw, that pic is exactly what I pictured in my head, finally… smile My head is a bit thick today, so tuff to get thru.

1s is going through the body to the ground ring on the driver. The other 3s is going to the contact pad on the driver that feeds the FET (the one with the line of vias).

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You are talking abut a 4S setup? So in the pictures, isn't 4S going to feed the FET?

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Tom E wrote:

You are talking abut a 4S setup? So in the pictures, isn’t 4S going to feed the FET?

Correct, you kept talking about 1s and 3s so I was trying to use your terms to explain it.

LED = 4s

MCU = 1s

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All I'm saying is 16V - 12V is 4V, so that's what the MCU is seeing - tapping in between the 3rd and 4th cell (going from negative to positive) gives you 12V. The + end of the 4th cell is 16V. I can't see it any other way from the pics in posts 259 and 260. So in relation to earth ground, 12V would be going through the body, I would think?

In a 2S2P, only 4V would be going through the body?

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I think some of the confusion is about the order of the cells. I am calling the 1st cell the one on the far left of my diagram.

The body of the light carries 4.2v through it, just like a normal SRK as that single cell is all that is passing through the body.

The other 3 cells only connect to the contact plate in the tail and to the driver contact pads, which feeds into the FET on cell # 4 (the one on the far right).

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I discussed this with an EE friend here @work. His concern was the gate voltage compared to the source voltage coming to the FET. He reviewed the specs on the SIR800DP: N-channel, Vgs rated at +/- 12V.

Have you tried this on the bench yet? Were you planning on using one of our standard FET's? Have you looked into the voltage delta between the gate and source of the FET?

 

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Tom E wrote:

I discussed this with an EE friend here @work. His concern was the gate voltage compared to the source voltage coming to the FET. He reviewed the specs on the SIR800DP: N-channel, Vgs rated at +/- 12V.


Have you tried this on the bench yet? Were you planning on using one of our standard FET’s? Have you looked into the voltage delta between the gate and source of the FET?


 

No, I have not done anything more than the design in the OP, just a proof of concept really.

I was not real worried about the FET as I know they exist that would work. For example the old classic NXP have a gate to source voltage of 20v.

http://www.nxp.com/documents/data_sheet/PSMN3R0-30YLD.pdf

I am sure there are more options as well but the NXP is already proven and would work fine. I honestly notice very little difference in the real world between it and the sir800.

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For the NXP, yes, it won't blow up anything with a range of 20V, but the source to the FET is -12V compared to the MCU's supplied gate voltage to the FET, so even for the NXP, the FET will be always be on. This is what my friend is saying.

 

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Tom E wrote:

For the NXP, yes, it won’t blow up anything with a range of 20V, but the source to the FET is -12V compared to the MCU’s supplied gate voltage to the FET, so even for the NXP, the FET will be always be on. This is what my friend is saying.


 

I am not an expert on FET’s by any means.

When the MCU is not sending any voltage to the FET gate, It is an open circuit correct? I am not sure how the FET would turn on with an open circuit on the gate?

When the MCU sends the voltage output to the FET would it not turn on anyways?

Honestly I am not seeing how this setup is any different than using an LDO? Either way the gate sees +4v and the source is -12v?

I guess it is my turn to miss something?

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The source is -12V, while the gate is 0 to 4V, therefore when the MCU outputs what it thinks is zero, the FET sees it as +12V, because to the FET, the -12V is it's ground. So when you think you set the gate to 0, it's really a 12V difference over the source input to the FET, so, the FET is always on.

That's the way I understand it. Think it makes sense.

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