Interesting phenomenon with 445 & Boost

[RDTech]

Has anyone experienced this odd phenomenon with a Casio 140 diodes and boost driver?

Boost driver set (like I always do to 1000mA)
LD attached to driver
18650 300mAh battery attached for test (like always)

I am getting an oscillating beam, maybe 5Hz.

Tried 2 drives, more batteries and bench supply, same results. This leaves the LD? Right.

Anyone have any ideas..

Mitch

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[brando132]

IIRC it's the driver not getting enough juice.

 

[JLSE]

I made one laser with my own boost drives and experiance similar when
approching the higher currents.

Have you measured the total current draw from the battery?
Remember the driver has to meet the 1A draw for the LD PLUS
ramp up the voltage. The total draw of the cell is probably
in the area of 1.5A, maybe more, maybe less...

Also, wire gauge, switch capacity, and resistance at any point
in the host will all contribute.

The laser should not be doing this, unless the driver is stressing.
Try running one with an LM317, I doubt this will continue to happen.

Also are the batteries protected? I have seen odd behavior before with
protected cells and high current demands.

 

[RDTech]

All the batteries are Protected. I will for SH*T sake, rip one of the 3600mAh batts apart and remove said protection device. Good call if it works. Yes, the Pos wire heats up, Some things do not add up.

Thanks, let me tear apart a battery

 

[JLSE]

All the batteries are Protected. I will for SH*T sake, rip one of the 3600mAh batts apart and remove said protection device. Good call if it works. Yes, the Pos wire heats up, Some things do not add up.

Thanks, let me tear apart a battery

Removing the protection can be dangerous. You should first
test the total draw on the battery and see what numbers you
are working with.

I stick with 2x CR123's and avoid boost at this current level.
Keeping your driver and battery on their edge wont make for
reliability.

The AMC 7135 boards and 2x CR123 batts work very well together,
and will prove more reliable in the long run by the looks of it.

Boost can be too finicky at these levels and the alternative
is far cheaper.


EDIT* Hang on... Is this the driver your using????

I assumed you were using a LavaDrive of some sort... The diver may be pulsed...

Aslo, is there no inductor on that board??? :wtf:

 

[RDTech]

YES, IT A LAVA BOOST DRIVE AND NOT MODULATED (sorry about caps, I wasn't yelling) it is definitely self oscillating. Very odd. If I wanted to oscillate it, I'd have added a nice little SMT 555 circuit. Might be cool anyway. The driver (boost as far as I know does not have an accessible enable pin.

 

[Jimmymcjimthejim]

Hang on... Is this the driver your using????

That looks like the battery's protection circuitry.

 

[RDTech]

This is a photo of the PROTECTION circuit on the battery, not the driver, the driver is a lava boost driver...

MItch

 

[RDTech]

This is the protective circuit board removed from the battery shown. The unit will still oscillate with it off as well. I have been told to use 2 - CR123 batts, wont that go over the specs for boost drive (lava)>

 

[JLSE]

lol... im such a n00b at times :undecided:

I thought you posted that pic in the first post to show your driver..

Using 2x CR123 with a AMC7135 driver has been the best setup
for me. The batteries last nice and long and there is no extra work
for the batteries other than to supply the current. They are low drop
out and handle higher currents very well.

No flickering or battery issues... I was using my 3410 based boost,
but will only do so with lasers that are small. If I run a 445 at 1 amp or
higher, I tend to put them in a host with plenty of room for a heatsink
and 2 Cr123's.

Just makes more sense to me that way...

Im waiting on some small hosts, they will be used with my boost boards,
only because there is no way to get rid of the heat from running at 1+Amp
anyway.

And im not too fond of 5 second on times..

 

[RDTech]

lol... im such a n00b at times :undecided:

I thought you posted that pic in the first post to show your driver..

Using 2x CR123 with a AMC7135 driver has been the best setup
for me. The batteries last nice and long and there is no extra work
for the batteries other than to supply the current. They are low drop
out and handle higher currents very well.

No flickering or battery issues... I was using my 3410 based boost,
but will only do so with lasers that are small. If I run a 445 at 1 amp or
higher, I tend to put them in a host with plenty of room for a heatsink
and 2 Cr123's.

Just makes more sense to me that way...

Im waiting on some small hosts, they will be used with my boost boards,
only because there is no way to get rid of the heat from running at 1+Amp
anyway.

And im not too fond of 5 second on times..

Re the AMC7135 available with a schematic? Are they fixed or adjustable? I have seen them on DE, looks like some have 1-4 AMC7135 IC's What is their Actual size? Have a couple I can test ( will pay you) DE will take 1/2 month to deliver, I'm impatient .

Mitch

 

[JLSE]

Re the AMC7135 available with a schematic? Are they fixed or adjustable? I have seen them on DE, looks like some have 1-4 AMC7135 IC's What is their Actual size? Have a couple I can test ( will pay you) DE will take 1/2 month to deliver, I'm impatient .

Mitch

Im waiting on a batch right now... The boards are NOT adjustable BUT,
they can be easily modified. 4 chips on one board gives you 1400mA.
Take away one and its 350mA less.. 1050mA, 700mA and 1 chip for 350mA.

I have been getting approx 1.6W @ 1400mA driven by 2 CR123's

You can also etch smaller boards that are long and slim opposed to the
round disc they come in. They are 17mm in dia, but can also be shaved a bit more.
Excellent boards, IIRC discovered and first used with a red laser here on LPF
by member Gazoo a couple years back.

For 20 boards, its like 30$ or 1.50 ea give or take.. A great deal.

 

[ped]

@RDtech

Dont double post, edit the first post to include the new information.

I got neg rep by a very anal member, 10 days after i double posted.

 

[JLSE]

@RDtech

Dont double post, edit the first post to include the new information.

I got neg rep by a very anal member, 10 days after i double posted.

If its your thread, I say post till your hearts content!


Damn those neg- reppers :tsk:

 

[qumefox]

microboosts will pulse themselves when they get too hot. Have you tried heatsinking the driver itself?

 

[RDTech]

I had it thermally potted.. Maybe it had some sort of runaway with one of the other components/ I yanked ( at great dismay) the module apart, exhumed the laser diode, still potted in Aixiz case and put it on a high rel cc generator. Works fine now with a massive heat sink

2 - cr123 batts work fine, but they put out a massively bright beam. Since my lasermeter goes unly up to 1 watt, it saturates VERY quickly.