foulmist
0
- Joined
- Mar 29, 2011
- Messages
- 1,056
- Points
- 48
Um... I DID IT!!!!!!!!!! YESSSSSSSSSSSSS!!!!!!!
I kept the components as minimum as possible and simple. I got a board with 16.6x15.5 size.. But my final pcb should end up a little smaller than my protoboard (which is made by hand).
No pot for current settings. Fixed resistors are used instead. For pot I need more components on the board which are unnecessary!
so ..
specs in boost mode :
constant current output
2.1A max at Vin=>=3.6V & Vo<=5.0V
1.5A at Vin>=3.6V & Vo=6V
input - you should get one of those 2800-3000mAh 4.2V Lithium Cells I am waiting for mine from Larry to test it with battery instead of bench PSU but as long as the battery can deliver 4A it's good!
CHEAP CHINESE BATTERIES WON'T DO! ALREADY TESTED WITH TRUSTFIRE - PROTECTION KICKS IN! ALSO TESTED WITH NON-PROTECTED CHEAP ONES.. 1A at the output max
To regulate the output at the 1.8A current - a 3.6V is desirable for minimum input when using 445nm diode.
as the batteries starts discharging 3V will still regulate the current with around 300mA lower if the battery can handle the current.
specs in buck mode:
constant current output
max output tested 2.5A @ 4.5V (may go to close to 3A not tested)
max input in buck mode should be 5.5V (6V is absolute maximum - not recommended)
common specs:
input voltage - 2.9-5.5V (3.6V for ~1.8A@4.5Vout)
max output voltage - 6V (but current will drop)
when heatsinked it can run nicely for long periods of time.
overvoltage/overtemp protection
After consistent test on my test load with 2,3,4, and 5 rectifying diodes
At 6V(max) output the max output current drops slightly. ~1.5A in boost
At <=5.5V output current is steady 1.75A (as set) in boost!
At 3.3V output the current can go above 2A in boost and around 3A in buck!
I hooked my diode straight on the output with risk to kill it but I had to try it in REAL conditions. I put my DMM in Amper meter mode and hooked it between the + of the driver and diode. The big direct press heatsink is especially made for this test
In some of my tests the diode survived a 1.95A current.
good thing I didn't set it higher the driver was in buck mode. In boost mode I have tested it til 2.1A. It might go higher but it's unlikely.
I spent quite some time trying different inductors and this pretty much is the optimum one and size is PERFECT too.
I present a video of it in action with bench supply, A140 laser diode and current and voltage readings of input and outout. I simulated the battery voltage drop down to 2.8V and up to 4.2V.
I will update this thread with a battery powered operation when I get the... battery itself maybe after new year... (post companies.. shhish )
So far no glitches at the output. Driver is steady. Diode still lives. I am happy. Happy holidays to all :beer:
p.s. I will make a few commercial boards after new year if anyone is interested. I can tell you the price after I do some math and figure all the costs.
:beer:
I kept the components as minimum as possible and simple. I got a board with 16.6x15.5 size.. But my final pcb should end up a little smaller than my protoboard (which is made by hand).
No pot for current settings. Fixed resistors are used instead. For pot I need more components on the board which are unnecessary!
so ..
specs in boost mode :
constant current output
2.1A max at Vin=>=3.6V & Vo<=5.0V
1.5A at Vin>=3.6V & Vo=6V
input - you should get one of those 2800-3000mAh 4.2V Lithium Cells I am waiting for mine from Larry to test it with battery instead of bench PSU but as long as the battery can deliver 4A it's good!
CHEAP CHINESE BATTERIES WON'T DO! ALREADY TESTED WITH TRUSTFIRE - PROTECTION KICKS IN! ALSO TESTED WITH NON-PROTECTED CHEAP ONES.. 1A at the output max
To regulate the output at the 1.8A current - a 3.6V is desirable for minimum input when using 445nm diode.
as the batteries starts discharging 3V will still regulate the current with around 300mA lower if the battery can handle the current.
specs in buck mode:
constant current output
max output tested 2.5A @ 4.5V (may go to close to 3A not tested)
max input in buck mode should be 5.5V (6V is absolute maximum - not recommended)
common specs:
input voltage - 2.9-5.5V (3.6V for ~1.8A@4.5Vout)
max output voltage - 6V (but current will drop)
when heatsinked it can run nicely for long periods of time.
overvoltage/overtemp protection
After consistent test on my test load with 2,3,4, and 5 rectifying diodes
At 6V(max) output the max output current drops slightly. ~1.5A in boost
At <=5.5V output current is steady 1.75A (as set) in boost!
At 3.3V output the current can go above 2A in boost and around 3A in buck!
I hooked my diode straight on the output with risk to kill it but I had to try it in REAL conditions. I put my DMM in Amper meter mode and hooked it between the + of the driver and diode. The big direct press heatsink is especially made for this test
In some of my tests the diode survived a 1.95A current.
good thing I didn't set it higher the driver was in buck mode. In boost mode I have tested it til 2.1A. It might go higher but it's unlikely. I spent quite some time trying different inductors and this pretty much is the optimum one and size is PERFECT too.
I present a video of it in action with bench supply, A140 laser diode and current and voltage readings of input and outout. I simulated the battery voltage drop down to 2.8V and up to 4.2V.
I will update this thread with a battery powered operation when I get the... battery itself
maybe after new year... (post companies.. shhish )So far no glitches at the output. Driver is steady. Diode still lives. I am happy.
Happy holidays to all :beer:p.s. I will make a few commercial boards after new year if anyone is interested. I can tell you the price after I do some math and figure all the costs.
:beer:
Last edited:
Good job and good luck!
Xmas and New Year and my supplier informed me that they are out of some of the items.... 
