J
Jonathan Kirwan
I just picked up some of the high efficiency Vishay 7-segment displays
(red) after having used in the past much less efficient ones. I just
got them in the mail today. Just trying one of the segments with 5V
and a 15k/5% resistor gave me 220uA of current, suggesting a drop of
1.7V on the LED segment, itself. And the brightness was just fine for
my needs. I pushed it a little harder with a 6.8k/5% and got about
480uA, suggesting a drop of 1.74V, and the brightness was more than
I'd probably need. So with a 3X mux for 3 digits, even that much
would only require driving them at about 1.5mA on a 1/3rd duty. Which
is better than I'd hoped -- less than 2mA averaged current per segment
in a multiplexed display of 3 digits.
They are cheap and available in hobbyist qtys (50 cents each in 1's at
Allied [TDSR1360].) What I'm curious about is if there are others I
might also consider in this area of performance. Either cheaper and
as good or just better. I'm not thinking exclusively about red - so
I'm interested in particularly efficient 7-seg displays in other
colors, as well. But red is good, too. I'm just not well-versed on
the various manufacturers and who else might also be competing in this
area.
Thanks,
Jon
(red) after having used in the past much less efficient ones. I just
got them in the mail today. Just trying one of the segments with 5V
and a 15k/5% resistor gave me 220uA of current, suggesting a drop of
1.7V on the LED segment, itself. And the brightness was just fine for
my needs. I pushed it a little harder with a 6.8k/5% and got about
480uA, suggesting a drop of 1.74V, and the brightness was more than
I'd probably need. So with a 3X mux for 3 digits, even that much
would only require driving them at about 1.5mA on a 1/3rd duty. Which
is better than I'd hoped -- less than 2mA averaged current per segment
in a multiplexed display of 3 digits.
They are cheap and available in hobbyist qtys (50 cents each in 1's at
Allied [TDSR1360].) What I'm curious about is if there are others I
might also consider in this area of performance. Either cheaper and
as good or just better. I'm not thinking exclusively about red - so
I'm interested in particularly efficient 7-seg displays in other
colors, as well. But red is good, too. I'm just not well-versed on
the various manufacturers and who else might also be competing in this
area.
Thanks,
Jon
