Using More that 2 Flight Sticks

[Binome]

Originally Posted by RyanN

At School: Yes, but notice that any voltage changes will cause your analog sensors to mess up on your OI like your joysticks, so be careful, and I highly advice you to make a voltage regulator that will ensure a steady voltage.

The OI has an internal LM7805 or similar regulator IC. Voltage input is already regulated.

[RyanN]

Originally Posted by Binome

The OI has an internal LM7805 or similar regulator IC. Voltage input is already regulated.

If it is regulated, then the regulator is not very good... Last year we hooked up 2 9V batteries in parallel (so the total voltage was still 9V) but all of our analog stuff was messed up.

[DonRotolo]

Voltage regulators have a parameter called "Dropout"- the input voltage at which regulation no longer occurs.

A 78xx series regulator requires an "overhead" - the voltage difference between input and output - of something like 2 or 3 volts to avoid dropout. Low-Dropout (LDO) regulators exist, with overheads of a fraction of a volt.

Your 9 volt transistor battery was very close to the dropout limit for a 7805 regulator already. If you draw more current from the battery tha its rating - I think it's 20 mA for that kind of battery - the battery output voltage can sag (get lower). You may want to check what current the OI draws, either by looking at the specs or by direct measurement, and decide if a two 9 volt batteries in parallel is sufficient to power the OI reliably.

Don