Micro laser driver - fits Aixiz/DX modules

[SargeMX5]

What sets the duty cycle? Does the chip turn off when the temperature threshold is exceeded or do we just have to remember to turn it off after X amount of seconds?

 

[rkcstr]

What sets the duty cycle? Does the chip turn off when the temperature threshold is exceeded or do we just have to remember to turn it off after X amount of seconds?

The chip does have internal thermal protection, but so far I have not seen the driver shut down due to temperature.  I'm not sure at what temperature it would, they only list the maximum die temp of 150C.  What I'm setting as my "shutdown" threshold is 100C to avoid damaging anything onboard (including the laser diode and other parts) and since it would likely burn you if you touched it.  

Basically, I'm trying to play it safe by suggesting you do not use these for continuous operation more than a couple minutes max.  That's not to say they wouldn't continue to function beyond that point.  If you took measures to cool it better (ie airflow, heatsinking, etc), it's quite possible that even at the highest output, it would operate much longer to indefinitely (assuming the diode holds out).

I've considered sandwiching a small piece of aluminum between the chip and the board to increase the amount of heatsinking, but that may interfere with it fitting in the Aixiz module as there is only about 2-3mm between the chip and housing.

 

[jake21]

ill take some if u have any for sale at the moment or later on down the road

 

[BlueFusion]

BAHAHA.
ok not to be rude
but you claim this as a low dropout device at 2.25 volts
yet a 317's dropout is only 1.7 volts
and my drivers can be filed down to fit these housings and have only 1V drop.
:

 

[rkcstr]

BAHAHA.
ok not to be rude
but you claim this as a low dropout device at 2.25 volts
yet a 317's dropout is only 1.7 volts
and my drivers can be filed down to fit these housings and have only 1V drop.
:

These are considered 1V LDO regulators, but when regulating current, you must add the reference voltage (1.25V) to the "dropout", which makes the minimum input value 2.25V over your intented driving voltage.

Have you actually TESTED that your drivers produce proper regulated output at your claimed values?  They will continue to put out current, but it will decrease as you drop below the minimum input voltage.

Also, while I appreciate criticism, I don't appreciate ignorance.

 

[BlueFusion]

I have indeed. the reference voltage does not come into the dropout if configured correctly.
My drivers supply a very nice voltage and current just as they should.

 

[rkcstr]

I have indeed. the reference voltage does not come into the dropout if configured correctly.
My drivers supply a very nice voltage and current just as they should.

You use a design I'm not familiar with. I'm basically a hobbyist in electronics, my knowledge of circuit design is only what I have seen before, meaning I learn as I go, typically following what I see in datasheets or find online.

For your circuit, I'm guessing that instead of using just a resistor to modify the voltage to the adjust pin, you use a circuit with the LM385 to modify the reference voltage and I'm guessing that's how you achieve your lower dropout voltage by sort of bypassing the internal voltage reference?

I would have appreciated if you would have just said "You can do this better by [insert useful criticism]" rather than basically saying what I'm doing is no good. While I understand that my circuit is rather simple, it was something I designed for myself but saw others had interest in it as well, so I decided to buy some extra parts to make some for other people as well.

 

[BlueFusion]

I'm sorry. I was a little harsh and I appreciate competition.
Makes people push for better designs and prices.
My circuit uses a voltage reference diode as the ref. voltage, which is modified by resistors. Hence the reference voltage is separate from the total drop of the whole circuit.
Your circuit does look like a nice little one and I totally understand your position, my FusionDrives only became available through popular demand.

 

[chimo]

The MC33269 is a low drop-out regulator - in voltage mode. There are ones with a lower drop-out but they don't work in 3 terminal mode. In current mode, the circuit must be changed and it has a higher drop-out, but lower than the 317 series.

BF, have you asked yourself why this keeps occuring?

 

[desslok]

[quote author=desslok link=1206339013/0#12 date=1206450912]Is that current regualting or just voltage?

It is a current regulator.[/quote]

Nice. This looks really well done BTW, nice job. I will keep a lookout for the for sale post in the future and would be interested in a few.

 

[amkdeath]

Blue, PLEASE STOP ADVERTISING YOUR FREAKING FUSION DRIVES. I WILL BE SURPRISED IF YOU EVEN GET THE FIRST BATCH OUT...

not to be rude.

I have received 'test' drivers from this guy, and I can confirm they are t eh pehmp sheyt. (In other words these things are AWESOME!!!)
They are SMALL, they REGULATE CURRENT, and they come in many forms and colors. well, maybe not many colors.

I have received 2 38mA drivers with the SOT-223 package, and 1 400mA driver with the D2Pak regulator. so far: good. Review to come soon. Trust me, these are awesome.

more to come soon,

amk

P.S. no hard feelings blue

 

[rkcstr]

The drivers are now available for purchase

 

[jake21]

thanks rkcstr i got my drivers today, nice looking

 

[HZolly345]

What would be the neccessary out power/ma for 3xAAA's connects to a stonetek.com sony 16x burner diode? Like if I wanted the high outpust temp for burning but a cycle of about 1 min or 1m:30seconds?

 

[rkcstr]

What would be the neccessary out power/ma for 3xAAA's connects to a stonetek.com sony 16x burner diode? Like if I wanted the high outpust temp for burning but a cycle of about 1 min or 1m:30seconds?

4.5V (3x AAAs) is below the minimum input voltage. It'll still put out current, but below the expected output. You'll need at least 2.25V higher than the diode voltage for it to put out regulated current, otherwise the current will drop as the input voltage drops, hence its called the dropout voltage. Most people use 2 lithium batteries (3-3.6V each), because of their higher voltage and capacity than alkalines.

 

[HZolly345]

What would be the neccessary out power/ma for 2x lithium ion batterys( 3.6v each, with 500ma each?) that is connected to a stonetek.com sony 16x burner diode? Like if I wanted the high outpust temp for burning, and a bright dot?