Looking for brave laserists to test the boost driver

[Bbe]

5.5V maximum output voltage is a bit too low

If you don't find anything better, you can try the ACS1500SE in boost mode.
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About this testing -- 5 drivers found a new curious and brave owner, thanks to everyone who are in!

 

[Bbe]

Thread update:
It seems 2 members have left the project so 2 drivers are back in the game. The rest ones has been shipped out.

 

[Shmackitup]

I built a pointer last week using the 3A Boost Driver and a NUBM07 diode. I had the driver turned up all the way and it maxed out at about 2.9 amps I believe. When I first tried it out it worked fine but after a few times turning it on and off it started flashing about every second or so. I swapped a few different batteries and it did the same thing. They are pretty decent 18650 batteries and have a good discharge rating. Only a few times of quickly half-pressing the tail switch was I able to get it to turn back on at full power. I then hooked it up to my benchtop power supply and cranked it up to 6A at 4.2V. I was then able to get it to come on full power but sometimes I'd have to quickly make contact a few times before it would go on at full power and not flash. Turning down the potentiometer a little seems to alleviate this problem. I will try to get some even higher rated discharge batteries to test to see if that helps.

Anyways, here are some pics of the pointer:

 

[Unown (WILD)]

Thread update:
It seems 2 members have left the project so 2 drivers are back in the game. The rest ones has been shipped out.

Thanks man. I gotta wait for a flashlight to come in and I gotta send it to lifetime to make the heatsink. Probably gonna be a month or so. You know... China -_-

 

[Giannis_TDM]

I built a pointer last week using the 3A Boost Driver and a NUBM07 diode. I had the driver turned up all the way and it maxed out at about 2.9 amps I believe. When I first tried it out it worked fine but after a few times turning it on and off it started flashing about every second or so. I swapped a few different batteries and it did the same thing. They are pretty decent 18650 batteries and have a good discharge rating. Only a few times of quickly half-pressing the tail switch was I able to get it to turn back on at full power. I then hooked it up to my benchtop power supply and cranked it up to 6A at 4.2V. I was then able to get it to come on full power but sometimes I'd have to quickly make contact a few times before it would go on at full power and not flash. Turning down the potentiometer a little seems to alleviate this problem. I will try to get some even higher rated discharge batteries to test to see if that helps.

Anyways, here are some pics of the pointer:

Sounds like an inductor Isat issue if it's drawing that much current, How much current is it drawing from your supply and how hot is the inductor getting? If you have a scope measure the Sw node going to the inductor, Then tell me the duty cycle of the PWM waveform.

 

[Bbe]

I built a pointer

Thanks for taking the time to do this. Most likely protection from undervoltage is triggered. This may be a short-term drawdown that is not visible on the multimeter. You have two drivers with different threshold settings, 2.9V and 3.3V. Maybe it makes sense to repeat the experiment with the second driver.

I tried to simulate a laser diode and a battery with my tools, see the video for what came out of it. First, I turn on the driver at 4.2V and then lower the voltage until the discharge protection is triggered. At 2.9V, the driver turns off and then I turn the voltage back up. At 3.1V, it turns on. At the end of the video, I just do a few on-off cycles. As we can see, there are no "unnecessary shutdowns". The heat dissipation of the driver is 2W, the irregularity of the output current in the entire range of input voltages fits in 3%. Tomorrow I will try to repeat the same thing but with an 18650 cell and mechanical button.

The same thing at 4.8V. Input current exceeds 5.4A when the "battery" is close to low

 

[Giannis_TDM]

Thanks for taking the time to do this. Most likely protection from undervoltage is triggered. This may be a short-term drawdown that is not visible on the multimeter. You have two drivers with different threshold settings, 2.9V and 3.3V. Maybe it makes sense to repeat the experiment with the second driver.

I tried to simulate a laser diode and a battery with my tools, see the video for what came out of it. First, I turn on the driver at 4.2V and then lower the voltage until the discharge protection is triggered. At 2.9V, the driver turns off and then I turn the voltage back up. At 3.1V, it turns on. At the end of the video, I just do a few on-off cycles. As we can see, there are no "unnecessary shutdowns". The heat dissipation of the driver is 2W, the irregularity of the output current in the entire range of input voltages fits in 3%. Tomorrow I will try to repeat the same thing but with an 18650 cell and mechanical button.

That sounds about right too, Thanks for taking the time to make the video. Although I do have to point out that the 07s vF at 3A is 4.7v, Consider changing to that for more accurate results tomorrow.

 

[Bbe]

Consider changing to that for more accurate results

Thanks for the tip, I set it to 4.7V in the follow test.

I used two pretty well 18650s, but they have LOW discharge rate so they cannot provide the enough current without significantly voltage drop. The first battery is ~40% charged, the second is fully charged a hour ago.

 

[Serveurperso]

Need some, where to buy

 

[Unown (WILD)]

OMG I forgot about this!