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

Yes, sorry, I'm guilty of abbreviations as well, makes the writing easier and the reading tougher :-(

Perhaps it is nice if someone would write a short history of how the different BLF-drivers have evolved.

NP (No Problem) It just mean a bit more googling. Didn't mean to bring the thread OT (Off Topic)

;-)

Actually no problem at all. I think it's "healthy" having to google some stuff. Takes a little extra time - but the stuff you learn by searcing yourself, rather than having it served, sticks better to memory. I actually hate when people expect to have everything served. So no problem! Alread learned a ton from BLF.

Back to topic :-)

Im sure you have the attention of many others, including me. :bigsmile: Thank you for posting such a great inexpensive mod. This is something that almost anyone can accomplish.

Quick update, I'm excited about this driver mod it's so easy and cheap.

I modded an old knackered ak47 driver last night and the PH4030 mosfet fits easily, it's so tiny it's incredible, it's thinner than the attiny13, I was worried about losing it in the weave of the carpet! The solder pads line up perfectly.

At five amps output it was running cold and had modes. Voltage drop across the mosfet was a lowly 25mV in high mode.

Winner winner chicken dinner.

Im looking for some for duel channel firmware to try this is begging to have a AMC7135 fitted.

Great to hear that the voltage drop over the FET is only 25mV@5A, that is nothing to worry about: the average steel spring has a voltage drop of 250mV at 5A!

I had not thought about that possibility. You can keep the 7135 'around the corner' for that, but you will have to cut the trace to the MCU and air wire it to a different pin I guess (I have not looked into the pin-layout of Toykeeper's dual firmware for the EE A6 group buy driver)

Thanks djozz and comfychairs. I am going to try this driver mod.

Back in 2012 I posted This thread about an alternative way to use attiny 13A/7135 drivers with higher voltage series cells for series LEDs. At that time a few others were doing Zener mods and none of the Oshpark boards had been done yet.

In 2013 I asked Mattaus to design a 10mm driver using the Attiny13A and one 7135. He had created other boards by then and so had others so the Oshpark projects thread was born.

A bit later Brian(WarhawkAVG) asked me to collaborate with Mattaus and Comfychair on another board that combined the Attiny13A with an FET and the BLF DD family of drivers was born. I hadn’t really contributed much in the design of them but I did suggest using the LFPAK56 for its small size and high current capability. We ended up going with the larger FET because Comfychair who was doing the lions share of the testing had a lot of them to work with.

With the concept proven wight began developing designs that took advantage of the smaller FET size to make single sided drivers and that has now progressed to multi-channel drivers.

All throughout this time a bunch of truly inspired people(literally a who’s who of BLF) have been developing and tweaking the code for the 13A mcu to take better advantage of the new board designs.

We now have a member who (RMM, Mtnelectronics) who has set up shop and along with much of what one needs for modding sells many of these designs as well as coming up with new boards on his own.

DrJones, TomE, ToyKeeper, I can’t keep track of all the people writing and developing code and there are a slew of people now with more joining in adding their 2 cents. I didn’t start this but it sure has been fun to be a part of.

Edit- this post is not about claiming any credit, that all goes to Matt, CC, Alex, Brian, and all the others that pushed to get where we are now. It is just how I came to be involved and my perspective on the process.

How interesting :slight_smile: does this mean i should be possible to upgrade all of these various FET/attiny13a drivers with a 7135?

very nice ,espacially when it does not need programming ,to make it even cheaper ,will it work with the 3 leg FET ? (salvaged old vgas and motherboards have lot of them)

FET-specs are beyond my understanding, but I'd just try some out, as long as you can make them fit. Those 3-leg FETs have long leads, they canbe bended to anywhere I suppose.

true its dangerous to bend those legs ,will have to wire solder them.

Oh, and thanks Rufusbduck for the short history of the BLF direct driver builds :-) . I had the pleasure of watching it all a bit from the sideline, these developments I think are among the absolute highlights in the (short) history of BLF (at least in the period that I have been a member).

So I was looking at NXP’s (the FET manufacturer) videos on YouTube and when they said they are at Manchester I laughed, that’s like 30 miles from here! And I’m buying their transistors from China which is thousands away, crazy world.

I used to wonder why we can buy CREE LEDs from China at relatively low prices considering it is American company, then I came to realize that CREE has manufacturing plant in China.

Another similar story is that Samsung does operate a battery manufacturing plant in my country (known as SDI) and the plant is only 30km (18.75 miles) away from my home. But since they only produce for exportation purpose we don’t get to buy them any cheaper or any more conveniently. :frowning: We still have to buy these Samsung batteries from China and waiting for month(s) to get here.

Hi djozz,

Are the stars on the driver (Dealextreme version) can help to change into different mode group, or does it only come with 5-mode?

If you can’t order from RMM IOS is also inexpensive with mode choice accessed by stars.

Oh okay that is a really good one. It is 20mm and it can fit perfectly in some flashlights.

Thanks. :slight_smile:

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Soldering the stars change mode groups.

DX drivers arrived quite quickly around 11 days, here’s how I modded mine.
DX 1A 2/3/5 mode Drivers, and PH4030 FETs.

Diode delete for increased gate drive, and wires soldered for bench testing. I like the 10% 100% mode group best so far.


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Output current is a percentage of high mode. So if high is 4.5A, low mode (first star) will be 450mA.

Group of modes:
1st Star : Low (10) - High (100)
2nd Star: Low (5) - Medium (30) - High (100%)
3rd Star : Low (5) - High (100) - Strobe
4th Star : Low (5) - Medium (30) - High (100%) - Strobe – SOS
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Thank you to all the great brains out there who figure these things out.