[FTC]: HiTechnic Sensor Multiplexer question.

Is it possible to run the HiTechnic Sensor Multiplexer off of the main power from the robot. Is it strong enough to hold up to the power difference. Has a team tried this already?

AND OR… is it legal to do this, if it is possible?

An excellent question and one my team has wondered about. We’ve been unwilling to try for fear of frying the mux with the higher voltage. If you ask on the forum, get the official ok, and are willing to risk it, we’d love to know the results.

Haha, thats my delema too. Our team would like to be able to use more sensors, but dont wanta have to deal with another battery, as half the time, they forget to turn off the camreas we have on the bot.

We havent gone and bought a Multiplexer yet for this reason, now if it was to be on the main power, then we would be all for more sensors!

Reading through the FTC Offical Fourm…

Originally Posted by FTC0025
The HiTechnic Sensor Mux uses an external 9v battery to supply
power to each of the attached sensors. We had problems with
this last year as it is not wired to the main robot switch, so our
drivers would either forget to turn it on with obvious results, or
forget to turn it off, thereby leading to dead 9v batteries not
discovered until just prior to the beginning of a match.

We’d like to know if it would be acceptable to use an LM7809
voltage regulator and associated circuit either on a breadboard,
or soldered protoboard to power the mux. Input would be 12v
from the main battery, output would be the regulated 9v into the
mux.

A: No. The sensor mux may only be powered by the provided 9v battery box.

SOOOO Nope. Dangit.

You found my rule request post. :slight_smile: The mux is a 9v part, shoving
12v into it would not be good, as there is no internal regulator.

Xander told me last year that he had a prototype from Hitechnic
that did have a regulator and hence you could plug into the main
robot battery, but I haven’t seen it hit the market yet and there’s
been no more info from Xander on the subject.