Considering Driver Efficiency

[ouch3994]

Hey all, I have recently began to assemble a 1w 445nm laser just for the sake of getting used to using a micro boost driver, and only one battery cell. My previous setup was using two 18650's and a lm317 setup. However, I have noticed quite a variation between different companys' designs for lasers...

WL uses one 18650 cell,
Lazerer uses two 3.6v cells in some cases
Moh's custom driver is a linear driver, requring the two cells...

Is there any benefit to using the boost driver designs compared to a linear driver that require a higher input voltage?

Which is more efficient?

 

[Fiddy]

what often determines what driver you will use, is what/how many battery's can fit in the host.

 

[rhd]

There's no simple answer, although there are some general principals that usually hold true.

1) If you have a lower battery voltage than your diodes Vf, you don't have any choice but to go with a BOOST.

2) If you have higher battery voltage than your diode's Vf, a decent BUCK driver will typically be more efficient than a LINEAR driver.

3) In some cases however, you'll have "ever so slightly higher" battery voltage than your diode's Vf, and in such a situation, the efficiency difference between LINEAR and BUCK may be tiny.

4) Since LINEAR drivers can often get much smaller (fewer components), you may find LINEARs more useful. Red diodes are a great example.

 

[ouch3994]

thanks guys i purchased a microboost drive recently, and i will most like order the microflex and moh's designed linear driver to play around with all three for comparisons... :/ now i need a better soldering iron...