Need help with alterations

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Outback0619

New Member

• Jan 20, 2019

• #1

This is a circuit board for an LED head light flashlight. It has a hi, low, and stobe feature. I would like to disable the strobe feature. I am an amature, please help.

 

JonSea

Well-Known Member

Most Helpful Member

• Jan 20, 2019

• #2

Not possible. It's programmed in to the microcontroller chip.

 

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Outback0619

New Member

• Jan 20, 2019

• #3

Is it possible to reprogram?

 

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sagor1

Active Member

• Jan 20, 2019

• #4

The 8 pin chip is just a MOSFET to switch the current. Not sure what the 6 pin device is, but looks like some switching device as well, triggering the gate of the MOSFET device. I don't see anything with "logic" on this board, maybe it is elsewhere in the flashlight?

 

AnalogKid

Well-Known Member

Most Helpful Member

• Jan 20, 2019

• #5

Some flashlights are controlled by an ASIC specifically designed for flashlight control. Old memory says Sanyo used to make one. In any case, altering it is not possible.

ak

 

JonSea

Well-Known Member

Most Helpful Member

• Jan 20, 2019

• #6

I think you'll find the 6 pin chip is a "mystery microcontroller" as Big Clive puts it in his numerous teardown videos of similar devices.

Reprogramming isn't practical without a development chain for the micro, documentation you can read and whatever programmer is needed - assuming the chip isn't a one-time-programable part.

 

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Outback0619

New Member

• Jan 21, 2019

• #7

Thank you all for your replys so I can't just remove these chip and wire direct?

 

alec_t

Well-Known Member

Most Helpful Member

• Jan 21, 2019

• #8

Outback0619 said:

So I can't just remove these chip and wire direct?

Click to expand...

One of those chips will likely be providing a PWM signal for the Hi/Lo function. It may also be controlling LED current in some other way. You might get away with wiring direct. You would, of course, then lose the Hi/Lo option and might over-drive the LED(s).

 

AnalogKid

Well-Known Member

Most Helpful Member

• Jan 21, 2019

• #9

Outback0619 said:

Thank you all for your replys so I can't just remove these chip and wire direct?

Click to expand...

Depends on the switch. If it is an momentary on/off, then the chip controls the actual turning on and off of the LED. If the switch is an alternate-action (push-on / push-off) then you might be able to wire the switch directly to the LED (and its current limiting). Hmmm ...

What are the values written on the four paralleled resistors to the right? Also, if you sketch out a schematic of the entire light (not just the board), there probably is a way to bypass the chip.

ak

 

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Outback0619

New Member

• Jan 21, 2019

• #10

Thank you all for your expert opinions. In light of your help I am choosing to suffer the option rather than render the light useless.

 

KevinW

Member

• Jan 21, 2019

• #11

I purchased a clip on flashlight for a hat similar to that, it had too many options for me, all I wanted was a flashlight.
The electronics kept draining the batteries so I removed everything, added a new switch and placed a current limiting resistor in series with the led.
Now I have what I wanted in the first place and the batteries last like they should.