Description A MOTOR

[0001] This invention relates to a motor with an improved startup perfoimance.

[0002] In state-of-the-art motor embodiments, the switching elements called theimic protectors switching to cut off state in case of high current and/or high temperature conditions and protecting the motor by cutting the mains voltage are used.

[0003] In state-of-the-art European Patent Application no. EP1569325, a desαiption is given of a motor protected against high current and high temperature by a theimic protector. In the invention which is the object of this document, triac is used instead of PTC, and thus, since the triacs are not driven by a microprocessor, as the theimic protector switches to off state triacs can not be driven. When the theimic protector switches to on state both triacs are ignited in certain intervals and the startup of the motor is provided.

[0004] In a motor which is controlled by a controlling unit with a miαoprocessor and protected against high current and temperature by a thermic protector, both of the triacs connected to the primary winding and the secondary winding are ignited at the same time and the startup of the motor is provided. As the motor startup is provided, the continuous operation triac continues to be driven to keep the motor operation but the starter triac used only for the motor startup is turned off. When the theimic protecter switches to cut off state, the motor stops but the continuous operation triac continues to be driven. When the temperature of the theimic protector drops and it switches to on state, even the continuous operation triac runs, the starter triac can not be ignited as the miαoprocessor does not have any infoimation about the state of the theimic protector. In this case, the motor startup does not occur since the starter triac is not ignited when the theimic protector switches from off state to on state.

[0005] The objective of the present invention is the realization of a motor the startup of which is provided by switching-on the starter triac according to the state of the thermic protector.

[0006] The motor realized in order to fulfill the objectives of this invention and explicated in the first claim and depending claims thereof comprises a theimic protector which protects the motor by switching to the cut off state in case of high temperatures and high currents, a motor driving circuit having power elements to provide the motor start and motor stop, and a control unit providing the control of the motor driving circuit by a miαoprocessor. The control unit provides the evaluation of the voltage values on the

resistors connected to the common teiminal of the motor or the motor driving circuit by the miαoprocessor, and easy startup of the motor by controlling whether the theimic protector is in on or off state in order to ignite the starter triac according to this evaluation. Thus it is provided to detect whether the motor is energised or de-energised wherein the theimic protector switches to on/off states in case of high temperature or high electric current.

[0007] In an embodiment of the present invention, whether the theimic protector is in on or off states is detected by measuring the current on the resistor connected to the teiminal of the continuous operation triac and accordingly, the motor is started by providing the ignition of the starter triac.

[0008] In another embodiment of the present invention, the off state of the theimic protector is detected by measuring the voltage on the terminals of the continuous operation triac, and accordingly the motor is started by providing the ignition of the starter triac.

[0009] In another embodiment of the invention, the off state of the theimic protector is detected by measuring the voltage on the common terminal of the motor, and accordingly the motor is started by providing the ignition of the starter triac.

[0010] The motor realized in order to fulfill the objectives of this invention is illustrated in the attached figures, where :

[0011] Figure 1 - Is the schematic view of a motor, a motor driving circuit, a control unit and a voltage/current measurement circuit.

[0012] Figure 2 - Is the schematic view of a motor, a motor driving circuit, a control unit and a voltage/current measurement circuit in another embodiment of the invention.

[0013] Figure 3 - Is the view of a motor, a motor driving circuit, a control unit and a voltage/current measurement circuit in another embodiment of the invention.

[0014] Elements shown in figures are numbered as follows :

1. Motor

2. IVbtor driving circuit

3. Control unit

4. Thermic protector

5. Power supply

6. , 16. Triac

7. Current/Voltage measurement circuit

[0015] The motor (1) of the present invention is driven by a power supply (5). The motor (1) comprises a main winding (MW), an auxiliary winding (AW), a common terminal

(C) where one temiinals of these windings (MW and AW) are connected to each other, a thermic protector (4) positioned between the common teiminal (C) and the power supply (5), cutting off the mains voltage by switching to the off state in case of high electric current and/or high temperature, and a motor driving circuit (2) connected to the main and auxiliary windings (MW and AW) providing to start or stop the motor

(1).

[0016] The motor driving circuit (2) comprises a starter triac (16) connected to the auxiliary winding (AW) in series, triggered for a while during the startup to provide the running of the motor (1), switched off after the motor (1) start, and a continuous operation triac (6) connected to the main winding (MW) in series, providing the controlled starting or stopping of the motor (1) even when the starter triac (16) is switched off, driven when the theimic protector (4) is switched to the off state.

[0017] The motor (1) comprises one or ore voltage/current measurement circuits (T) one ends of which are connected to the control unit @, the other to the motor driving circuit (2) or the common teiminal (C) of the motor (1) and a control unit @ which provides the motor (1) start by triggering the continuous operation triac (6) together with the starter triac (16) when it is detected that the thermic protector (4) is switched to the on state due to an inσease in voltage or current of the voltage/current measurement circuit (T) so as to detemrine the state of the thermic protector (4). Thus, it is provided to control the starter triac (16) by detecting the state of the theimic protector (4) and to obtain the needed start torque for the motor (1) start.

[0018] In this embodiment, one teiminal (T2) of the continuous operation triac (6) is connected to the main winding (MW), the other teiminal (Tl) to a teiminal (Tl) of the starter triac (16), and the gate terminal (G2) is connected to the control unit @ via a resistance (R2). One teiminal (T2) of the starter triac (16) is connected to the auxiliary winding (AW) as the other teiminal (Tl) is connected to the other teiminal (T2) of the continuous operation triac (6) and the gate teiminal (Gl) is connected to the control unit @ via a resistance (Rl). Those resistances (Rl and R2) connected to the control unit @ are used to limit the electric currents on the gate temiinals ( Gl and G2) of each triacs (TRl and TR2). There is a voltage/current measurement circuit (T) between the control unit @ and the motor (1) or the motor driving circuit (2) in order to detect the state of the theimic protector (4). The control unit @ drives the starter and the continuous operation triacs (16 and 6) and the motor (1) is controlled by switching on/ off by means of the continuous operation triac (6). After the motor (1) is supplied with the mains voltage, the starter and the continuous operation triacs (16 and 6) are

switched-on and the starter triac (16) is driven during a period needed for the motor (1) start, and thus, current passes through the main winding (MW) and the auxiliary winding (AW). The motor (1) starts rotating as a result of the torque σeated on the motor (1) by the current passing through the auxiliary winding (AW). The starter triac (16) is not driven from that time on. Thus, the unnecessary power consumption after the motor (1) startup is prevented.

[0019] In this embodiment, if the theimic protector (4) switches-off for any reason, the motor (1) can not be fed by the mains energy and stops. In this case, the voltage/ current measurement circuit (T) reads "no voltage". When the operating conditions are maintained, the theimic protector (4) switches-on to provide the motor (1) to be fed by the mains voltage. In this case, the voltage/current measurement circuit (T) reads a certain voltage. This voltage data is evaluated by the control unit @ and it is decided that the theimic protector (4) is on, and the starter triac (16) is triggered by the control unit @. At this moment, as the continuous operation triac (6) is already on, a healthy startup of the motor (1) is provided by driving both triacs (6 and 16). The starter triac (16) is driven for a certain time period and then switched-off to provide the noimal operation of the motor (1).

[0020] In an embodiment of the present invention, the voltage/current measurement circuit (T) comprises a resistance (R25) placed between the temiinal (Tl) of the continuous operation triac (6) and the power supply (5), having a connection with the point connecting the Tl temiinal and the control unit @ so as to enable the control unit @ to evaluate the current passing through it (Figure 1).

[0021] In another embodiment of the present invention, the voltage/current measurement circuit (T) is a voltage divider which is comprised of two resistances (R4 and R5) connected in series. In this embodiment, the temiinal of one (R4) of the resistances is connected to the terminal (T2) of the continuous operation triac (6), and the end of the other resistance (R5) is to the line where the power supply (5) and the triacs (6 and 16) are connected. The point where both the resistances (R4 and R5) are connected to each other is connected to the control unit @. Thus, the voltage on the continuous operation triac (6) is deσeased by the voltage divider and evaluated by the control unit @ to decide whether the theimic protector (4) is switched to the off state or not (Figure 2).

[0022] In another embodiment of the present invention, similar to the above embodiment, a voltage divider which is comprised of two resistances (R6 and Rl) in series are used as the voltage/current measurement circuit (T). In this embodiment, the voltage divider is placed between the common terminal (C) of the motor (1) and the line connecting the

power supply (5) and the triacs (6 and 16). The point where both of the resistances (R6 and Rl) are connected to each other is connected to the control unit @. The voltage between this circuit (T) and the common teiminal (C) of the motor (1) is deσeased by the voltage divider and evaluated by the control unit @ to decide whether the thermic protector (4) is switched to the off state or not (Figure 3).

[0023] The motor (1) is fed by an alternating current power supply (5), and preferably used in the compressors of the cooling systems.

[0024] In yet another embodiment of the present invention, there is a capacitor (CT) which inσeases the motor (1) efficiency between the main winding and the auxiliary winding (MW and AW).

[0025] In all of the embodiments of the present invention, in the voltage/current measurement circuit (J), sensors which can measure electric current or voltage can be used instead of the resistances (R3, R4, R5, R6, and Rl) used .

[0026] By this invention, for a motor (1) comprising a control unit @ and a theimic protector (4) which protects the motor (1) from high temperature and current, by transferring the data including the state of the theimic protector (4) to the control unit @ and by igniting the triacs (6 and 16) according to the state of the thermic protector (4), the motor (1) is provided to start without the need for additional circuit elements.