Technical Questions re 3 of my Mac Lights

[DrBay]

Hello all:

I have a few technical questions about some Macs that I purchased used here and on USN.

First, my two Tri EDC's (Copper and Ti) give off a low pitch sound in low mode and a higher pitch sound in medium mode. No sound is emitted in high mode. New batteries do not make the sounds go away nor alter them. Is this normal?

Also, I recently bought a Haiku. The seller said that it is perfect but I can only sporadically get low mode. There does not seem to be any rhyme or reason to how or when I can access low. 99% of the time! it only operates in high mode. Maybe I don't know the operating modes. A new battery did not solve the issue.

Any thoughts are greatly appreciated.

Thanks!

 

[Mattaus]

The whine is PWM noise. The only way to get rid of it is to reflash the MCU to run its PWM at a higher frequency. This isn't guaranteed to work but its normally successful.

No idea about the haiku. That's seems to be a defect rather than a systematic problem.

- Matt

 

[ibcj]

On the Haiku check and make sure the light engine is securely seated in the head. I had erratic switching behaviors and it turned out that the light engine became loose and just needed to be screwed in.

 

[nbp]

Try running your Haiku on a li-ion cell. I think your mode shifting will improve.

 

[archimedes]

Yes ... search for "inductor whine" (Macs), and mode shifting challenges associated with lower battery voltage and the original Haiku driver (McGizmo).

The key to shifting modes on McGizmo is to try to make the "off" duration on the "blink" as short as possible. It can take a little bit of practice to get used to switching modes reliably. When battery voltage gets low, it can be very difficult to switch beyond "high" (back to "low" mode) - as the mode seems to get stuck there.

These links might be helpful ...

https://www.candlepowerforums.com/threads/374235

http://www.candlepowerforums.com/vb...he-PD-lights&p=4314617&viewfull=1#post4314617

 

[DrBay]

Great advice, all. Good to know that the Tri-EDC whine is not a mechanical defect issue. As for the Haiku modes issue, I tightened the light engine (it needed a small turn to seat fully) and stumbled upon clicking as fast as I could to get some sporadic mode changes. Switching to a Li-Ion battery has me almost where I need to be. A little more physical training and and I should be "there." Thanks for the assists!

 

[archimedes]

Great advice, all .... Thanks for the assists!

:twothumbs

 

[RedLED]

Worthwhile information on our special lights!