RC Electronic CAR power system parts and function
First of all, we should know that there are several ways to sell RC car.
1.RTR: means Ready To Run, which describes products that arrive fully pre-assembled and with everything they need to get up and running included. The seller has almost assembled all the parts, you only need about 30 minutes to start Let the car run
2.ARR: stand for 'Almost Ready to Run', which indicates that there's either some building or construction that you have to do, or that there are a few things missing from the package, such As a transmitter or motor. If you've already been into RC hobbies for a while, this can be a great step up in terms of difficulty and expertise. It can also be a sweet money-saver if you already have a compatible transmitter/ Motor!
3.KIT: Basically, you have to build almost everything yourself. There are very few rules as to what are supplied in these; some cover absolutely everything, only as parts rather than pre-assembled, while others are just the bare framework of a Model. The great thing about kits is their flexibility, which allows you to put a lot of your own creativity into your RC model, and make it something truly yours. The mechanical knowledge that building a kit will give you is also invaluable for keeping your Vehicle happy and healthy while it's up and running.
Obviously as a beginner, RTR/F models are most friendly. But we can also know something about our car due to the car maintaining.
So here is a brief introduction to the power system parts and function of the RC electronic car.
Parts & Function:
The power system parts and function of the RC electronic car primarily include motor, ESC (Electronic Speed Controller), Servos, batteries, Transmitters, receivers.
1.Motor:There are two variants of the motor: a brushed motor and a brushless motor. The brushed motor has a small brush that can switch power through the coil. The brushless motor requires an external controller to switch them.
Brushless motors are generally more efficient, can handle higher speeds and torques, can handle large amounts of power, and last longer because they have no brushes to wear. The outside of the layman has permanent magnets, and the outer cover rotates with the shaft. There are permanent magnets inside the inner ring, and the outer casing does not rotate. The outer rotor has a higher torque but a slower speed and is typically used for large propellers. The inner ring has a low torque but can reach very high speeds, so it can be used in geared applications such as RC cars or small propellers.
Cars in the RC world usually have an interesting rating called Kv. Although it may be in kilovolts, it is actually a revolution per volt per minute. In theory, a 300Kv motor will rotate at 900 rpm at 3 volts. The lower the Kv value, the greater the torque, but the smaller the motor speed; the higher the motor speed, the higher the speed the motor will have, but the lower the torque.
When looking for a suitable propeller, potential buyers may encounter something like "1247" or "12x4.7". These define the size and pitch of the propeller. In this case, people will look at a 12-inch diameter, 4.7-inch pitch propeller. The pitch is defined as the distance the propeller moves in the air in one revolution under ideal conditions. Propellers are also commonly classified as "slow fly" propellers and ordinary propellers. Slow propellers are typically used for gearing or low speed applications and have a curved leading edge for increased efficiency. Ordinary propellers have a straight leading edge for increased efficiency and are typically used for faster motors.
Gears in the RC world are usually sold only as an alternative to RC automotive gearboxes. They are never sold by diameter, but are sold only by pitch (tooth pitch) and number of teeth. The spur gear is usually a large gear that is rotated by a pinion that is directly connected to the motor.
- ESC
ESC is very simple to use. Their purpose is to obtain low power input signals in the form of ppm and battery voltage and convert them into signals that are useful to the motor. They also have a voltage that is output through the signal line and is typically used to power the receiver.
There are basically two types of motor controllers: brushless and brushed controllers. Brushed motor controllers are only suitable for brushed motors and send them PWM, pulse width modulated (not PPM, pulse position modulation) power inputs. These are simple and inexpensive, and can also be used to control lighting and anything else that requires DC power. Brushless motor controllers are very different. They switch power between three combinations of the two poles of the three poles of the brushless motor and adjust their speed based on the PPM signal.
The difference between automotive ESC and aircraft ESC is that automotive ESC usually has a power switch, heat sink and reversibility, while aircraft ESC is not reversible (switching any two motor wires to reverse the motor), no power switch, usually There are only a few radiators.
The ESC is also programmable, usually through a programming card or through a receiver and transmitter. It depends on the ESC, but usually has programmable brake, start and battery voltage cutoff settings.
- Batteries
The battery has many different shapes and sizes, chemistry and ratings.
The two most common chemicals used in RC applications are NiMH or NiCd and lipo batteries.
Nickel-hydrogen (NiMH) and nickel-cadmium (NiCd) batteries are cumbersome, fragile and outdated. The only benefit is that they may be cheaper and not sensitive to shock, vibration, overcharging and deep discharge.
Lipo batteries are lighter, smaller, can provide large currents, and have a large capacity. The 5000mAh Lipo battery is about the size of a 2500mah NiMH battery. However, if they are pierced, the discharge is too far or too far away, they will swell. This means that the battery is about to explode. Do not use the battery again and handle it safely. If you move on, it is likely to explode in a large fireball and fire chemicals and burn objects everywhere. Do not short-circuit these batteries as they may explode.
The battery has many different ratings:
mAh or Ah: represents milliampere hours or ampere hours. This is the capacity of the battery. 1Ah = 1000mAh, which means the battery can deliver one amp of current in one hour (or 1000milli amps in one hour)
S and P: represent the number of batteries connected in series and the number of batteries connected in parallel. The number of batteries connected in series determines the voltage, and the batteries in parallel determine the capacity.
C rating: This is how much current the battery can give you. Multiplying the capacity of the battery (in ampere-hours) by this rating gives the current in amps. Usually two are specified. The lower is the continuous rating and the higher is the pulse discharge rating.
Use a standardized connector for all lipo batteries to use any battery on any device and easily interchange them. Such as the commonly used XT60, DEANS plugs.
- Transmitter
Also often abbreviated as Tx, this is the thing that actually takes your commands and sends your receiver the commands for the servos and the motors.
There are many Transmitters available on the market nowadays, and the low-cost ones start around $30. However, remotes for RC airplane or helicopter pilots, with programmable features, model memory, and computer simulators can start around $150 and go to nearly $3000.
Old RC Remotes have a certain frequency that they operate on. Older, analog remotes operate on lower frequencies, which were determined by a crystal. Modern, digital, remotes usually operate in the Gigahertz Range, often at 2.4GHZ.
RC airplane and helicopter remotes have control sticks, which are mostly self explanatory. Usually, one of the two control sticks on an airplane remote is the throttle control stick, and is not spring loaded in the vertical direction, which means it will not spring back When you let go. Remotes are usually available with this stick on either the left or the right side, and are sold as mode 1 or mode 2. RC car remotes have a trigger and a knob to control different things.
Most RC remotes have something next to the Control sticks called the trim. this basically slightly alters the position of your control sticks, and is useful for finely altering the position of the servos, or the starting point of a motor controller. Transmitters also often have Reversing, which reverses the output signal of the control sticks. this is usually controlled by a series of switches at the bottom of the transmitter.
The number of channels a remote has shows how many things it can control. For example a three channel remote could control three things, such as three servos, three motors, or a combination of any of those. Motor controllers and servos receive the same type of signal.
Most Transmitters need to bind to your Receiver to ensure proper communications. How to do this depends on your Transmitter/receiver.
Many transmitters need 12v to operate, usually supplied by 8AA batteries.
- Receiver
The Receiver must operate on the same frequency as the transmitter, and the two will usually be sold together. Replacement or extra receivers are commonly available, so that they do not need to be switched out if one has more than one devices requiring a receiver.
The receiver usually receives power from a motor controller, simply by plugging it into one of the signal ports. Servos receive power from the receiver.
The Polarity of the plugs is usually found out by trial and error, in one way it will work, and the other way it probably will show a flashing light or something similar. Make sure to never connect one wire one way and another with opposite polarity To that wire, because depending on what those two things are, they will most likely be damaged, because one is going to be reverse polarity.
Some servo or motor controller connectors have a small plastic tab on them, and can therefore only be used with RC car receivers that can easily be removed with wire cutters.
Be careful with the antennae of digital receivers, because they are rather difficult to reattach.
- Servos
Servos are geared motors connected to potentiometers that are usually capable of 180 degree rotation, but with RC control usually only rotate 90 degrees. They take the receiver's commands In the PPM form and rotate to a set position. They will attempt to hold this position if f force is applied. Although normal servos have a limited range, there are extended range servos, which rotate 360 degrees or more, and even continuous rotation servos, Which have no control electronics and function as a normal gear motor.
They all have the standard three tie connectors, with ground (black), +4.8 to 7.4v (red), and signal (white).
Servos are usually classified by weight, and also have a torque rating. This rating is usually given in Kg.
So a 50Kg servo could supply 50Kg of force 1cm out from the axis (or 25kg 2cm out from the axis, etc...).
Some Large servos need a separate power supply because of their current demands, and would most likely just burn through your speed controller's power supply or your receiver's PCB traces. Use an UBEC with these. this is basically just a step down voltage regulator that provides a Constant voltage to your servos.
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