djozz driver hack #2. (was: Colour driver build, based on D882 sot89 transistor?)

[djozz]

@Ouchyfoot

When you were trying various resistors, did you try it with no resistor and and just a bridged pad?

No I did not try that. These transistors are limited in their power rating (can’t remember what it was) and the way that they are connected, they are not, like 7135 chips, cooled by a pad directly connected to the ground ring. I think that maybe 1.5A is what they can handle at maximum (assuming that they burn off, say, 0.8V overvoltage with a fully charged battery). So for a high current channel a FET is needed, the next level can be provided by one of the transistors at 1-1.5A.

[alpg88]

@Cereal_killer

tterev3’s code (which is for a 12F617) will work on my driver with zero hardware mods! Same for Matt’s board but at only 1x 7135 per channel.

Just keep in mind parts for a single driver will run you around $9 (plus shipping) so in the end you’ll probably only save $2-3 over just buying a ready to install driver from me ($20) with my FW. If you want a whole bunch of fun modes (and dont mind not having brightness control over the individual colors) definitely consider super RGBWUV, I’ve ran it on my driver and it is fun (tho with that many modes I definitely prefer MELD for the much more advanced control).

Pretty much any of our options are far better than that I.O. POS driver and its horrible modes.

i realize the thread is over 3 years old, but do you still mod, and sell drivers? i would like to buy some.

[djozz]

@alpg88

@Cereal_killer

tterev3’s code (which is for a 12F617) will work on my driver with zero hardware mods! Same for Matt’s board but at only 1x 7135 per channel.

Just keep in mind parts for a single driver will run you around $9 (plus shipping) so in the end you’ll probably only save $2-3 over just buying a ready to install driver from me ($20) with my FW. If you want a whole bunch of fun modes (and dont mind not having brightness control over the individual colors) definitely consider super RGBWUV, I’ve ran it on my driver and it is fun (tho with that many modes I definitely prefer MELD for the much more advanced control).

Pretty much any of our options are far better than that I.O. POS driver and its horrible modes.

i realize the thread is over 3 years old, but do you still mod, and sell drivers? i would like to buy some.

Cereal_killer has not been seen on BLF for more than year now, but tterev3 is around, and he even has released some new drivers recently.

[alpg88]

thank you, djozz, i will contact tterev3.

[tterev3]

@alpg88

thank you, djozz, i will contact tterev3.

Here’s my driver info thread: Introducing the MELD-X RGBW(uv) flashlight driver!

[Rufusbduck]

For some reason I missed this thread entirely. There’s so much I don’t know about even the more simple to understand circuits but I enjoy seeing them futzed with like this. So the center pin/tab is led-, left pin(tab on top) is control pin(base), and right pin is ground. I wonder if an RC filter could be placed in the pwm trace to control the voltage on the base. A sort of D/A converter with the output range tuned to the resistance range of the transistor.

[djozz]

@Rufusbduck

For some reason I missed this thread entirely. There’s so much I don’t know about even the more simple to understand circuits but I enjoy seeing them futzed with like this. So the center pin/tab is led-, left pin(tab on top) is control pin(base), and right pin is ground. I wonder if an RC filter could be placed in the pwm trace to control the voltage on the base. A sort of D/A converter with the output range tuned to the resistance range of the transistor.

I don’t think there is pwm at all in this driver, just per channel a standard voltage/current coming from the MCU that in the firmware is either switched on or off. The resistor value in between MCU and transistor determines how much of the current/voltage reaches the gate of the transistor and so how much current goes from ground to led.
(but none of the electronics experts at BLF ever commented on this driver, so I could be wrong)

But soon this thread will loose relevance, the driver is only still for sale at Mtn now, and there’s currently just 15 pieces left, I doubt that Hank will be making more of them….

[Rufusbduck]

That could mean the value is simply set to 255/255 but if pwm were used then maybe some kind of D/A converter could be used to convert the pwm signal to a variable voltage. Moot point if the driver disappears as have many others.