comfychair-inspired quick+cheap+lazy single-sided 17DD FET-driver (poor man's nanjg92)

Yes, I do bend the legs with small pliers. The last few I did I bended the third leg sideways and included it in the big solder blob to the ground ring (in the OP picture it just hangs loose). That makes it just a little bit extra solid.

I have a couple of the ’generic nanjg with 8x7135 from fasttech.
Does this mod work with those?

Also I have some AOD510 MOSFETs. Can I use those fr this nod?

If so I guess I strip off all 8 7135s, but then what?

Thanks,
Jim

Edit: I did the mod, but not working… No light. Which MCU pin should go to which pin on the AOD510 MOSFET?

Just took a look at the AOD510 datasheet for you. AOD510 appears to be opposite of the PSMN3R0-30YLD. So the bottom left pin of the AOD510 goes to pwm.

Instead of mounting it upside down like the PSMN3R0-30YLD you could place it right side up if you have some kapton tape to insulate the bottom of the AOD510 from exposed pads on the driver.

If you have no way to insulate the bottom you could place the AOD510 upside down but it would need to be oriented differently from the PSMN3R0-30YLD.

Thanks. I think I figured out what’s going on (in my brain).

Awhile ago, there was discussion about a new version of the EAST-092 driver that was showing up from FT, and there was lots of discussion about replacing the MOSFET on the “new” EAST-092. The AOD510 was one of the ones I think comfychair had found and was recommending, and THAT was why I have a couple of the AOD510s.

Later, comfy started the thread about the NANJG-92, which was making an EAST-092-like driver from a NANJG driver by removing the 7135s and then adding a MOSFET upside-down. The pics on that thread and also the Ebay link to the MOSFET on that thread are gone now, so I don’t know exactly which MOSFET was linked originally anymore, but bottom line is that I got the two things (the choosing a replacement MOSFET for the “new” EAST-092 driver vs. the NANJG-92 driver build) kind of glommed together.

Having said that, since I still have the AOD510s and a couple of the NANJGs, can I use the AOD510 to make a NANJG-92? I think I need to know which MCU pin should go to the AOD510 Gate pin?

Thanks for helping UNconfuse me :)!!

Jim

EDIT: Could someone ohm out and tell me which MCU pin # should connected to the Gate on the MOSFET? I know that it’s the PWM pin on the MCU but which pin # is that?

Bottom left is gate which goes to the pwm pin on the attiny, 2nd pin in from the capacitor.

Hi,

In the pic in the OP, the “dot” in the corner of the MCU should designate pin #1, then you count down that side then up the other side.

So, if I’m understanding what you said, that’d be pin # 7 on the MCU?

The Nanjg board I have in an 8x7135 one so it’s laid out differently than the OP, so I’d need a pin # since the cap may be in a different place.

Thanks,
Jim


Actually, looks like it should be pin 6 :zipper_mouth_face:
Yet, in the pictures above pwm seems to be connected to 7.But I’m not sure I even know what I’m talking about at the moment. :ghost: I need sleep. :weary: The schematic picture is correct at least, fwtw.

Hi,

I’ve checked and double-checked, and on the board I have, it surely looks like MCU pin #5 is going to the 7135 input (Vdd) pin (== the Gate on the MOSFET replacement)? I soldered the Gate pin on the AOD510 to the Vdd pin on that one 7135 location and ohmed it back to the MCU and it comes up as pin #5 still.

Well, at least now I have light, but I’m not getting modes, so I’m suspecting I’m only getting light either because of a short or because I’m in DD.

This one uses pin 6 and This one you can’t tell since the traces are under the blue wire. Still, the 7135’s should tell you which is the pwm pin. With a 7135 at the top of the board, left is output, center is ground, right is pwm input. Output should connect to led- pad, ground may connect to ground ring though many just use the larger tab, pwm input is the only one that connects to the mcu.

Hi,

Yes, that is what I figured, i.e., the rightmost pin of the 3 pins of the 7135 is the input, so that is the pad I soldered the AOD510 Gate pin to, and I can ohm that back to pin 5 (I think) on the MCU. I’ll check that again tomorrow, but I know that that was the pad I soldered the Gate pin to, so I’m puzzled why I don’t seem to be getting modes.

Jim

BTW, I noticed that comfy’s original post/thread (howto: Build a Nanjg-092) mentions moving a capacitor. Is that still necessary? Maybe that’s why I’m not seeing modes?

Since the pics are gone from his original post, I can’t see which capacitor he was referring to, or where it needs to be moved? Anyone have any idea about that for a 8x7135 board?

EDIT: BTW, re. the question of which MCU pin goes to the FET Gate input, the pic in this post (#61, comfychair-inspired quick+cheap+lazy single-sided 17DD FET-driver (poor man's nanjg92)) seems to show air wire connection from MCU pin #5 to the FET Gate input.

EDIT 2: I think I give up. I was going to try a different FET, and ended up pulling one of the original7135 pads off, so I put the new FET on another 7135’s pad, standing up instead of flattened, and after that, I still get no modes. There was comment in comfy’s original thread about some NANJG firmware using different PWM frequency not working (not because of the different frequency but because it used different control method or something), so I’m starting to think that the NANJG I have is one of those.

Try stacking an extra cap on C1 or adding one between B+ and ground as close to pin 8 as possible.

Hi,

I haven’t tried that, but I found something (else) that is really puzzling me. I put a scope across the FET Gate and the board ground ring and when I power the board on, it is just constant. I’ve tried clicking a switch, but it stays constant. In other words, it doesn’t look like there is any PWM type signal. Just as a sanity check, I put the same scope across the same pins on an EAST-092, and I see the expected signal (e.g., different frequency square waves for different modes.

I’m trying to decide if I should sacrifice another driver and/or FET ??

Was the board tested before you did the swap? It’s possible you have a bad or mis programmed mcu. I’ve fried a few boards myself without understanding how or why. Keep trying and keep looking up threads that date from around this time as this was discussed for a few months.

Yes, this was a new “generic” NANJG 8x7135 from FT (this is the one with the mode groups via clicking in low mode) and I tested it before removing the 7135s.

One problem is the pics in the original (comfy’s) NANJG-92 thread OP are gone. Plus I’m still confused about something: Even though the pics are gone, I followed that original thread, and I could have sworn that the original mod had the 3 pin FET upside down and the 70n02/3 and AOD510 FETs were mentioned in the thread, so it seems like the AOD510 like I have should be mounted upside down.

Jim

EDIT: The other thing that makes it hard to check/remember is that the link to the FET in the OP of that thread is no longer existing also :(…

EDIT 2: Can someone who has this working post some pics, especially showing which cap to remove and where to put the cap?

I’ve spent the morning going back in time and found This post by WarHawk-AVG (post 44) that mentions it. I’ll look some more to see if I can find some other info. I’d suggest you google the different fets and compare gate pin locations, that’s what determines FET orientation.

Ohaya, do you recall This post or wight’s response ? A bit earlier in the thread he also mentioned that he thought it possible that a higher value cap should be used to absorb the spike but basically if it ain’t Atmel, it ain’t cookin’.

Hi,

Here’s some pics of my testing board.

Showing the top, AOD510 soldered to other 7135 position because pulled pad off other position:

Top view (you can see the missing solder pad):

Bottom view:

No, I don’t remember that post specifically - wish I had done this back then when comfy and wight were around :(…

Re. Atmel, do you mean that if the MCU isn’t Atmel that this FET conversion won’t work? I have to check that. As I said, the board I’m using is one of the “generic NANJG” drivers from FT. I was hoping to use that because it does mode switching by clicking rather than using the stars.

EDIT: That post you mentioned was about whether the MCU from a NANJG could be used on the BLFDD board, rather than about NANJG-92.

EDIT 2: One of the things that is really bothering me is why when I scope the FET pins, I get no (or constant) signal? In other words, it’s like the MCU is not working. Either that, or there’s a short to something like +V that I’m not finding

If the FET is This one then your hook up looks right. I don’t know why a different mcu should make a difference except in not being able to reflash it but WTHDIK. It may be that the different mcu is unable to charge the gate on the FET or it may be fried. To test that you could reinstall a 7135 to check it. On boards where I killed 7135’s the mcu was still able to drive the led in different modes but all were variations of moon.