SearchR/C Glossary

Several of the droid building techniques depend heavily on R/C tech, which, like most hobbies, has their own vocabulary. Here's the start of a simple glossary. We'll focus on electric vehicles as droids rarely use internal (or external for that matter!) combustion engines.

Also check out the Electrical Glossary

Terms

• Ah (Amp Hour)

(see Electrical Glossary)

• Battery

Common R/C batteries are 7.2V or 9.6V, though other voltages exist.

• Brushed Motor

A very simple electric motor. Generally the more volts you give it, the faster it spins, though often the power is controlled through a PWM signal instead of a pure voltage.

• Brushless Motor

• ESC (Electronic Speed Controller)

This is the throttle for an R/C car. It hooks up to the drive battery and regulates the power for the motor. Different types are required for brushed or brushless motors. They typically are rated for specific voltages and amperages (amps).

• LiFePO4 (Lithium Iron Phosphate)

A battery chemistry. Good energy density can be sensitive to charging/discharging, but considered safer that LIPO batteries. Caution should still be used though.

• LiPo (Lithium Polymer)

LIPO is a battery chemistry. Known for being able to store a lot of energy, but also very sensitive when charging/discharging and can burn up violently. Special care is needed when using LIPO batteries.

• Motor

What powers the vehicle! See Brushed and Brushless motors.

• NiCd (Nickel-Cadmium, aka Nicad)

Older battery chemistry. Cheaper than newer types of batteries they tend to be safer but don't store as much energy. These are usually what you'd see in a basic R/C car set or kid's R/C car. They are often still a good choice.

• PWM (Pulse Width Modulation)

Pulse Width Modulation is the idea of only sending an electrical signal part of the time. Like a fast square wave. PWM is used in R/C cars in a couple of ways:

1) To control the power to a brushed motor or other circuit. It's easier for modern electronics to send the full voltage part of the time than to send part of the voltage all of the time. So if you want to run at half-power, instead of sending 1/2 the voltage, a PWM controller might send all of the voltage for 1/1000th of a second, then nothing for 1/1000th of a second, then back to full power, etc.

2) It can be used to signal a desired position, like having a servo be all the way left, or all the way right. One direction might be a short "on" pulse and a long "off" pulse. The opposite direction might have a long "on" pulse.

• V (Volts)

(see Electrical Glossary)

• W (Watts)

(see Electrical Glossary)