The base platform of the Concept Car is a RC Car Model CE-5 from Carson Modellbau. This platform has the following parameters:
- Scale is 1:5
- Dimensions (l*w*h) are 80cm * 40cm * 23 cm
- Weight is ~ 8.4kg
- Top speed is ~60km/h
- Rubber wheels, 12cm in diameter
- Gear reduction from motor shaft to rear wheels is 20:44 * 20:77 (2 transmissions)
- Differential gear
The Concept Car engine is based on an air-cooled sensorless brushless electrical motor, which is presented in Figure 1.1.
Each part of the engine presented in Figure 1.1 is described in the following:
- The motor is a 1930/9 from Lehner Motoren and its characteristics are shown in Figure 1.2 [LM09].
- The engine control is a Power JAZZ from Kontronik. Its characteristics are presented in Table 1.1 [Kon09].
- The power is supplied by an accumulator with a nominal voltage of ~21V and the ability to sustain a permanent discharge current of at least 80A. The actual type and internal construction of the accumulator is irrelevant, as long as these specifications are met. Currently a 5S1 LiPo accumulator is used.
- The battery can be cut off from the engine controller with an emergency switch (200A)
- The 5-6V supply voltage of the steering servo (max. 3A) is generated by a high-efficiency step-down voltage converter.
Due to its sensorless nature, the engine tends to stutter when the car is pulling off.
|POWER JAZZ 63V||Characteristics (in English)|
|18-45||Cell count (NiCd/NiMH)|
|5-15||Cell count (LiPo)|
|13-63||Operating Voltage (V)|
|120||Contin. current (A) (2,4Ah battery)|
|200||Max. current (A) (15sec)|
|84||Size (mm) length|
|220||Weight (g) with cables|
|x||Auto Programming Mode|
|x||Automatic Power Consumption APC|
|x||EMF brake can be disabled|
|x||Reverse polarity protection|
|x||Short circuit protection|
|x||False start protection|
|x||-"- can be disabled|
|x||Slow down instead of cutoff*|
|x||Active free wheeling circuit|
|8-32||PWM frequency (kHz)|
|1.9||Total copper thickness|
|x||Reverse rotation direction|
The ConceptCar is remotely operated via a standard 2 channel 27MHz radio transmitter system. The channels are used for throttle and steering data. The radio receiver generates a 50Hz PWM signal with 5% to 10% duty cycle.
The steering system has simple mechanics; a servo motor sets the steering angle. Within a range of ±30° the steering angle is set to (pulse – 1.5ms) * 1° / 0.018ms, where “pulse” denotes the length of a PWM pulse at a PWM frequency of 50Hz.
The ConceptCar features a set of hydraulic brakes on the front wheels. At the current state, they can not be triggered separately, but the electrical system is already prepared for that.