[volt-nuts] Finally got around to modifying my Fluke 845ab with LED's

[David I. Emery]

On Wed, Sep 10, 2014 at 08:34:11AM -0400, Chuck Harris wrote:
> The white LED's I have worked with, though tiny, glow for a long time
> after being run at full brightness.  That persistence should make them
> poorly suited for use as a pulse modulated white light source.
> 
> The old GaAs LED's used to modulate well into the GHz region.  I doubt
> that you can modulate the white light output of a white LED with much
> depth into the 60Hz region.

	My understanding is that most "white" LEDs contain phosphors
excited by actual UV LED UV light drive (or at least used to) and so this
is not surprising at all.

	A blue LED might, on the other hand, be mostly LED light directly.

-- 
  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."