ComputerVoltageSources

I pulled my modular LCD apart and measured the backlight current.  I 
am running at 18 mA.  It's of average brightness, certainly easy to 
read but not overly bright.  I purposely set it as low as I could to 
minimize current.

It's hard to tell what the real spec is.  The LCD is a Optrex 
DMC20261NY-LY-ANE-CI.  There is a safe operating area curve for the 
backlight that max's at 260 mA at 25 C.  It looks like 152 mA is safe 
to 50 C. The forward voltage drop is measured at 130 mA.  It's 
probably pretty similar the the LCD we're planning on using so I'm 
still guessing we can run the backlight at much lower current.  
However, every backlight will probably be a bit different.

My 8x2 PSIM LCD does not have separate connections for the backlight 
and draws about 70 mA of current.  It is brighter.  I do locally 
regulate the +5 at the module.  I have 4 cabinets and only one has +5 
volts in it.  I used a 7805 and bypassed it with a 220 ohm 1 w 
resistor to split the current.  I don't like running heat sinks if at 
all possible and the resistor resulted in a reasonable heat rise for 
both components.

I would vote for whatever connectors fit but would certainly want to 
have a 6 pin MTA156 connector (ala MOTM) for those with +5 volts and 
room for local regulation.

Dave

--- In ComputerVoltageSources@yahoogroups.com, harrybissell > >
> > Backlight specification was 160 mA, Dave has run a similar one
> > at 16 mA with good results.