uC Based Led Lamp?

P

PICMICRO

New Member

• Aug 5, 2011

• #1

I ripped apart a small Led Lamp (that you mount on head), which ran on two Coin cell battery. I was imagining, the circuit was as simple as wiring the Led to the Battery through a current limiting resisters.
But I was amazed by seeing some surface mount components and what appears to be a uC.
What funny might they be doing there?
**broken link removed**

 

C

carbonzit

Active Member

• Aug 5, 2011

• #2

I'm guessing your little headlamp has a flashing mode as well as steady on, right? (Mine did.) That's done in that black blob, which is an ASIC (application-specific integrated circuit).

Not quite as many smarts as a microprocessor, but there are a whole lot of transistors crammed into that little blob.

 

Mikebits

Well-Known Member

• Aug 5, 2011

• #3

I was thinking some form of LED brightness controller to increase battery life.

 

K

kumaradhikari

New Member

• Aug 5, 2011

• #4

...........................................................

 

Last edited: Aug 5, 2011

P

PICMICRO

New Member

• Aug 5, 2011

• #5

Nope, Simple On/Off Mode only. No added features. How much battery might they manage to save? Or do they? (provided the extra circuitry they need to run)

 

Mikebits

Well-Known Member

• Aug 5, 2011

• #6

Something like this. Maybe? https://www.electro-tech-online.com/custompdfs/2011/08/AN3321.pdf

 

Last edited: Aug 5, 2011

KJ6EAD

Active Member

• Aug 6, 2011

• #7

It includes a regulator to keep the LEDs bright until the batteries are dead. Hook it up to an adjustable power supply and measure the current through one of the LEDs as you reduce the input voltage from 6V to find out how low the supply can go before the regulator drops out and the current falls.

You can also measure the quiescent current any time the batteries are hooked up and the light is off. It should be <10µA.

 

Last edited: Aug 6, 2011

P

PICMICRO

New Member

• Aug 6, 2011

• #8

Thanks for those infos.