Extra Battery

Is it legal to put an Energizer alkeline 9V on my arm to control custom circuitry which includes a servo? Technically, a servo is a mechanical unit that happens to have a motor inside. 9V power doesn’t drive a motor, a PWM signal from the RC does. I don’t see any complications with rule <R63>. Any thoughts?

No other battery will be allowed.

I believe all power sources must come from either the 12-volt or the backup battery. No fuel cells, additional batteries, solar panels or gerbils allowed.

wait one minute, what if you took a gerbil and hooked its wheel to a FP motor and used that as a generator?

<R59> says all 12V power must come from the lead-acid battery. I want 9V. <R53> says that all main power must come from the lead acid battery. I see custom circuitry power as secondary power. Can you give me a rule # to back-up your opinion?

<R53> prohibits any source of electrical energy besides the ES17-12 battery.

If your servo needs a +9 volt input, you may want to use a voltage regulator circuit which will lower the voltage from 12v to 9v. These are readily availible at RadioShack or your favorite overpriced electronics provider.

You might consider this:

Hope this helped.

Before spending too much time figuring out if your extra battery is legal, also decide if your servo is legal. I would say it likely isn’t. Please follow the 2007 Parts Use Flowchart on Page 19 of section 8 of the manual.

<R45> Items specifically permitted on 2007 FRC ROBOTS include:
• Additional HITEC HS-322HD Servos.

I believe only HITEC HS-322HD servos are legal.

All of you are right, only the Hitech servos will be allowed, and all power on the robot must be derived from the ES 17-12 or the backup battery.

You can’t put custom circuits in between the RC and any motors including servos. The servo must be directly connected to the PWM output on the RC. It already provides the correct voltage (7.2v) which comes from the backup battery.

The only power allowed is the power from the 12V battery or a 7.2 back up