Run-Time Plot - MadMax-Cyan Sandwich

[Roy]

This runtime plot is for a AA Minimag with a MadMax-Cyan Sandwich modification. Fresh Everactive alkaline batteries were used.

Equipment used is a photocell and a Radio Shack 22-805 multimeter with a PC interface that is using ScopeView software (V1.08).

The vertical axis is in ma and the horizontal axis is 15 minutes per division.

Be aware that your actual battery mileage may vary from that indicted by this runtime plot.

 

[Roy]

I just noticed that the Cyan MadMax has a 2.5 hour full bright runtime whereas my origional MadMax has a full bright runtime on 1.5 hours!
Has the curcuit been changed that much? Or is it just the difference between a white led and the cyan led?

 

[Jonathan]

Three 'off the cuff' possibilities that I can think of. 1) The Vf of the diodes is sufficiently different to make a difference. 2) The AA cells used in the test were from different batches and thus different. 3) The switch wasn't all the way 'on' in one of the tests.

I encountered this latter problem with the bike lights that I build, using a boost regulator circuit to run LEDs in the same fashion as the MadMax boards. Some switches would make a high resistance connection, dropping up to half a volt across the switch. The board would regulate for this difference, so the output was as bright, but the power being wasted in the switch meant a shorter run time.

-Jon

 

[Roy]

I had similar results to the origional MadMax runtime plot when I did a runtime plot using Li batteries. So, I don't think it is a switching problem.