Subject: Low-power LED questions
Date: 2 Oct 2002 22:14:22 GMT
Sender: William Sitch
User-Agent: tin/1.4.4-20000803 ("Vet for the Insane") (UNIX) (Linux/2.4.7-10smp (i686))
This is a followup to my "Motorcycle HUD" thread. I found the Linx KH-
series transmitter and receivers (thanks to the guy in comp.robotics.
misc who suggested them!), and now I'm wondering about low-power LEDs.
I'm trying to transmit the status of eight LEDs in a radar detector to
eight LEDs mounted in my helmet. The Linx KH transmitter has eight
input pins and a TE (transmit enable) which needs to be set to
The eight LEDs in the radar detector need to be connected to the
corresponding input lines on the transmitter. They also need to run
into a big OR gate to drive the transmit enable (so the Tx only sends
when the detector is going off).
Without knowing what kind of LEDs are in the detector and what kind of
voltages or currents drive them, what kind of 8-channel buffer and OR
gate would you recommend? The Tx will be mounted on the bike, so the
low-power isn't super important.
The receiver outputs will also need to be buffered to drive the eight
LEDs in my helmet. As fas as I can tell, the KH series receiver
latches onto the last received outputs, so I will need to enable
the LED driver (or buffer) from the DATA line on the Rx (indicating
data has been received). This is so the diodes will only be on when
the LEDs on the radar detector are on.
Again, what 8-channel buffer would you recommend? It needs to draw
very low current when not enabled, and should drive fairly low-current
LEDs when enabled.
What LEDs would you recommend? I need green, orange and red. I
can't find a mix'n'match mounting piece in DigiKey, am I looking in
the right place? The LEDs should be low current, small, directional,
and bright. *grin*
Lumex has some 'panel mount' LEDs that might be what I want. DigiKey
part numbers 67-1205-ND and 67-1213-ND.
Thanks for any help you can provide.
William Sitch, B.Eng., M.A.Sc. will(at)sitch.org http://will.sitch.org/