JLSE
1
- Joined
- Dec 13, 2007
- Messages
- 3,580
- Points
- 0
Hello all… I have been away for a bit and have been working on a new driver. It’s an interesting twist to the LM3410 configured in non-sepic mode and with a single inductor. This driver is also now common ground, you DO NOT have to isolate the case pin and diode from the body of your host. This allows for a more favorable and most perffered setup, and the ability to drive 550mA. If used as originally intended, a neutral case diode such as the 405 has to be used.
I have been testing this config with the long closed can red diodes found in the 6x sled. I, like many others, have run this diode at 400mA-550mA (driver stable) seeing outputs ranging from 275mW to well over 300mW (dependant on lens and diode efficiency). I think the best I can recall was in the area of 360mW. Even at that amount of current, the diode, if in a decent heatsink, can be run for several minutes before shutting down for a cool off.
The driver can be run at these ratings via a single 3.6v lithium. This looks to be a promising driver for smaller builds, not having to use 2x 3.6v cells, and being able to feed the diode 1/2 amp of current.
The output tested so far has very low ripple, with an average of 20mv +/-10 driving a LCC @ 513mA and 3.1v across the diode. The minimum current out, tested so far is 250mA @ 2.5v across the LD, I still have to test how much lower it will go from there. Though I doubt anybody would want lower than 250mA for a burning red.
While the driver is regulating current, I cannot claim it to be a true constant current driver, as I would when using this chip to drive 405nm.
There is a minor drift downward in mA at an average of 1mA every 30-45sec of steady on time. This is something I will be testing further, as ive been doing the first series of tests with CR123A 3.6v cells and running them down to empty. I’m sure the curve will lesson when tested with a bench supply.
This curve can be seen in the graph (see pics) over a 5+ min run.
The idea here is an option for a driver to work with a single 3.6v cell specifically and will be testing with 3x 1.2 nicad etc.
Anyways, I thought id share this, as ive been looking for a driver like this for some time now. I may also be offering these alongside the 8x drivers.
The driver PCB itself has been manufactured professionally, and measures 8mm wide x 16mm long. It fits easily inside and aixiz rear cap for protection.
So far no additional heatsink to the board or the IC is required at and above 500mA on a 3v load. No thermal shutdown has ocured in tests as high as 650mA, which the same LCC diode took like a champ, and hasnt seemed to have lost any output in mW from the torture..
I will update this thread as testing continues.
I have been testing this config with the long closed can red diodes found in the 6x sled. I, like many others, have run this diode at 400mA-550mA (driver stable) seeing outputs ranging from 275mW to well over 300mW (dependant on lens and diode efficiency). I think the best I can recall was in the area of 360mW. Even at that amount of current, the diode, if in a decent heatsink, can be run for several minutes before shutting down for a cool off.
The driver can be run at these ratings via a single 3.6v lithium. This looks to be a promising driver for smaller builds, not having to use 2x 3.6v cells, and being able to feed the diode 1/2 amp of current.
The output tested so far has very low ripple, with an average of 20mv +/-10 driving a LCC @ 513mA and 3.1v across the diode. The minimum current out, tested so far is 250mA @ 2.5v across the LD, I still have to test how much lower it will go from there. Though I doubt anybody would want lower than 250mA for a burning red.
While the driver is regulating current, I cannot claim it to be a true constant current driver, as I would when using this chip to drive 405nm.
There is a minor drift downward in mA at an average of 1mA every 30-45sec of steady on time. This is something I will be testing further, as ive been doing the first series of tests with CR123A 3.6v cells and running them down to empty. I’m sure the curve will lesson when tested with a bench supply.
This curve can be seen in the graph (see pics) over a 5+ min run.
The idea here is an option for a driver to work with a single 3.6v cell specifically and will be testing with 3x 1.2 nicad etc.
Anyways, I thought id share this, as ive been looking for a driver like this for some time now. I may also be offering these alongside the 8x drivers.
The driver PCB itself has been manufactured professionally, and measures 8mm wide x 16mm long. It fits easily inside and aixiz rear cap for protection.
So far no additional heatsink to the board or the IC is required at and above 500mA on a 3v load. No thermal shutdown has ocured in tests as high as 650mA, which the same LCC diode took like a champ, and hasnt seemed to have lost any output in mW from the torture..
I will update this thread as testing continues.
Attachments
Last edited:
