445nm connection problems and strange sound

[chipdouglas]

Tinnitus.???

 

[DTR]

The best thing I can suggest to rule out the connection issue is to start bypassing different parts of the host. Start with bypassing the tailcap with a by completing the circuit with a piece of metal or connect the driver straight to the battery. See if any of these solves the problem.

Also if you have a bench power supply that would make it a lot easier and can rule out an internal connection issue in the batteries protection circuit.:beer:

 

[532 with Envy]

I don't think i'm going to take it apart to fix it as the sound really doesn't bother me or effect the laser. The connection is poor and not doing as good a job as my imagination came up with, but it does still workThis is more than likely where the sound is coming from.

I will try to record the sound sometime this weekend and see if I can capture it. Really all this thread is just for general discussion and interest. Perhaps it's just me with my unstable head hearing voices again or a 'for-real' sciencie thing going on:yh:

 

[daguin]

There is no doubt in my mind that the "sound" is real. Sound being emitted by electronic components and connections are a fairly common phenomenon.

It is just that the sound is NOT being caused by or affected by the focal point of the beam. The sound is probably coming from the laser. The changes in the sound are acoustics in nature.

My main point was to simply take the mental focus off of the beam and onto the true source of the noise

Peace,
dave

 

[Benm]

Well, you could always do a blind test with a roommate, just have him put the target in the beam while having your eyes closed. You should be able to tell the difference, although the burning smell might give a hint by itself

 

[daguin]

Well, you could always do a blind test with a roommate, just have him put the target in the beam while having your eyes closed. You should be able to tell the difference, although the burning smell might give a hint by itself

The sound would still be "bouncing" off of the roommate's arm/hand. Having a cohort would eliminate it being his head changing position, but not the echo effect.

Peace,
dave

 

[532 with Envy]

There is no doubt in my mind that the "sound" is real. Sound being emitted by electronic components and connections are a fairly common phenomenon.

It is just that the sound is NOT being caused by or affected by the focal point of the beam. The sound is probably coming from the laser. The changes in the sound are acoustics in nature.

My main point was to simply take the mental focus off of the beam and onto the true source of the noise

Peace,
dave

I guess physically it is much more likely that the sound is coming from the host and not form a beam change. I think that I have to give it over to Dave here in the end.
@Dave....you did understand my question right off the bat,(I was impressed, judging how I explained it), and I think with your more vast understanding of such things you are right.

All being said it is still an interesting phenomenon. Hopefully I will be able to capture it on video to share.:beer:

 

[daguin]

I guess physically it is much more likely that the sound is coming from the host and not form a beam change. I think that I have to give it over to Dave here in the end.
@Dave....you did understand my question right off the bat,(I was impressed, judging how I explained it), and I think with your more vast understanding of such things you are right.

All being said it is still an interesting phenomenon. Hopefully I will be able to capture it on video to share.:beer:

The first time I had a driver "whine", it drive me bonkers. My ears are old and abused as it is. However, the whine was so quiet and above my "good" hearing range, that I could not locate the source by sound. Every time I turned my head, the sound would "move" or cease.

I ended up taking the whole laser apart again and testing it for the sound at EVERY step of the way. I FINALLY figured out it was a component on the driver itself. I replaced the driver and voila!

Peace,
dave

 

[Benm]

It can be a source of insanity Especially things that operate in the 10 to 20 kHz range can be difficult. It doesn't have to do with bad hearing per se either, its just that we're not very good at locating sounds at very low or very high frequencies in general.

In a scenario such as posted here, the sound can come from several locations at one: a bad connection, the driver inductor, and the target being ablated. Its very difficult if not impossible to pinpoint a sound source if its actually more than one at the same frequency and relative phase.

 

[532 with Envy]

"...the target being ablated."
This is what I thought might be happening but don't know enough about the phenomenon to understand.
Although, through our discussion here, I have begun to lean more towards Dave's idea that the change in sound is coming from and "echo" off movement/observer bias.
Physics is FUN:wave:

 

[EnergyCoherence]

The high pitch is probably the wires in the inductor vibrating. You can move a weak magnet near the inductor and change the frequency to confirm.

 

[Benm]

Probably.. inductors can be quite noisy, and its irritating if a switchmode driver operates in the audible range. Most small switching supplies (like laser drivers) operate at faster frequencies though, often between 100 kHz and somewhere up to 2 or 3 MHz.

As for sound coming from the target: I'm sure it is possible, but not very common. I can drive a 445 from pulsemode - perhaps its more feasible with that then it was with the lower powered red diodes.