Electric bicycle driving apparatus

1. An electric bicycle driving apparatus comprising:

a speed change mode operator to selectively output one of a first speed change mode signal and a second speed change mode signal;

a controller to receive the first speed change mode signal or second speed change mode signal output from the speed change mode operator and output a first control signal corresponding to the first speed change mode signal or a second control signal corresponding to the second speed change mode signal;

a motor driver to, when the speed change mode operator outputs the first speed change mode signal, receive the first control signal and output a first motor driving signal to drive a motor in a first speed change mode, and, when the speed change mode operator outputs the second speed change mode signal, receive the second control signal and output a second motor driving signal to drive the motor, the motor rotating with a driving force of the first motor driving signal, in a second speed change mode; and

a relay to selectively receive a relay switching enable signal from the controller, the relay being turned on in response to the relay switching enable signal to provide at least one of the first motor driving signal and second motor driving signal to the motor,

wherein the relay further includes at least one Zener Diode to cut off an abnormal signal from at least one of the motor driver and the motor.

2. The electric bicycle driving apparatus according to claim 1 , wherein:

the first speed change mode signal is a low-speed mode signal, and the first speed change mode is a low-speed mode; and

the second speed change mode signal is a high-speed mode signal, and the second speed change mode is a high-speed mode.

3. The electric bicycle driving apparatus according to claim 1 , wherein:

the first speed change mode signal is a high-speed mode signal, and the first speed change mode is a high-speed mode; and

the second speed change mode signal is a low-speed mode signal, and the second speed change mode is a low-speed mode.

4. The electric bicycle driving apparatus according to claim 1 , wherein the relay is electrically connected between an output stage of the motor driver and an input stage of the motor.

5. The electric bicycle driving apparatus according to claim 1 , wherein the relay comprises:

a first relay to provide the first motor driving signal output from the motor driver to the motor: and

a second relay to provide the second motor driving signal output from he motor driver to the motor,

wherein the first relay and the second relay are electrically connected between an output stage of the motor driver and an input stage of the motor.

6. The electric bicycle driving apparatus according to claim 1 , wherein the motor driver comprises:

a first motor driver to output the first motor driving signal; and

a second motor driver to output the second motor driving signal,

wherein the relay is electrically connected between at least one of output stages of the first motor driver and second motor driver and an input stage of the motor.

7. The electric bicycle driving apparatus according to claim 1 , wherein:

the motor driver comprises:

a first motor driver to output the first motor driving signal; and

a second motor driver to output the second motor driving signal; and

the relay comprises a first relay and a second relay,

wherein the first relay is electrically connected between an output stage of the first motor driver and an input stage of the motor, and

wherein the second relay is electrically connected between an output stage of the second motor driver and the input stage of the motor.