Abstract: The invention relates to a system for operating a first PEG element (PFC1) and a second PEC element (PFC2) in an interleaved mariner, said system comprising a first integrated circuit (IC1) having a first PFC controller, a second integrated circuit (IC2) having a second PFC controller, as well as a synchronization circuit (SYNC) connecting the first integrated circuit (IC1) and the second integrated circuit (IC2), whereas the synchronisation circuit (SYNC) is adapted to control the first integrated circuit (IC1) and the second integrated circuit (IC2) such that the first PFC element (PFC1) and the second PFC element (PFC2) are operated in anti-phase.

Abstract: A variable speed drive comprises a voltage filter and voltage polarity protection unit including 1) a voltage filter circuit configured for low-pass filtering a voltage of an associated DC voltage source, and 2) a voltage polarity protection circuit configured to prevent incorrect polarity parring between the variable speed drive and the associated DC voltage source; a DC power supply unit being operatively connected to the voltage filter and voltage polarity protection unit via at least a positive polarity connection; an inverter unit being operatively connected to the DC power supply unit, a controllable load dump inserted in series with the positive polarity connection between the voltage filter and voltage polarity protection unit and the DC power supply unit, and a control unit configured to control at least the DC power supply unit, the inverter unit and the controllable load dump.

Abstract: The invention relates to a system for operating a first PEG element (PFC1) and a second PEC element (PFC2) in an interleaved mariner, said system comprising a first integrated circuit (IC1) having a first PFC controller, a second integrated circuit (IC2) having a second PFC controller, as well as a synchronization circuit (SYNC) connecting the first integrated circuit (IC1) and the second integrated circuit (IC2), whereas the synchronisation circuit (SYNC) is adapted to control the first integrated circuit (IC1) and the second integrated circuit (IC2) such that the first PFC element (PFC1) and the second PFC element (PFC2) are operated in anti-phase.

Abstract: A system for protecting a power consuming circuit, the system comprising two terminals for receiving power and two terminals for providing received power. Between one of the receiving terminals and a providing terminal, a transistor is provided which is controlled by a Zener diode and to break the connection between one of the receiving terminals and a providing terminal, if a voltage over the providing terminals or the receiving terminals exceeds the breakdown voltage of the Zener diode.

Abstract: A system for protecting a power consuming circuit, the system comprising two terminals for receiving power and two terminals for providing received power. Between one of the receiving terminals and a providing terminal, a transistor is provided which is controlled by a Zener diode and to break the connection between one of the receiving terminals and a providing terminal, if a voltage over the providing terminals or the receiving terminals exceeds the breakdown voltage of the Zener diode.

Abstract: An electric circuit for supplying power to a DC application is disclosed. The electric circuit comprises a DC power source (1) connectable to an alternator charging circuit (2), an FET (T7), and a capacitor (8) connected across the gate terminal and the source terminal of the FET (T7). The drain terminal of the FET (T7) is connected to a negative terminal of the DC source (1). The FET (T7) protects the circuit against accidental connection of the alternator charging circuit (2) to the DC power source (1) with reversed polarity, by opening a switch (6) of the FET (T7) when this occurs. The capacitor (8) protects the FET (T7) from being pushed into avalanche in case a load-dump transient occurs. This is because the capacitor (8) in this case will charge and discharge, thereby introducing a time delay before the switch (6) is opened. Protection against load-dump transients is thereby obtained by means of a small component with low energy dissipation.

Abstract: A method and a control unit for controlling a power level being drawn from a power source (26). Based on a determined rate of change of a measured voltage (1) an estimated remaining runtime is calculated. The estimated remaining runtime represents a time where specific run criteria will no longer be fulfilled if the present power level is maintained. The estimated remaining runtime is compared to a threshold value, and in case the estimated remaining runtime is shorter than the threshold value, the power drawn from the power source (26) is decreased. Thereby the runtime for the power source (26) is maximised. This is particularly useful if the power source is a limited power source, such as a battery (26), e.g. for running a compressor (27) for a movable refrigeration system (24). The invention is suitable for automotive applications.

Abstract: A method and a control unit (4) for controlling a supply of power to an electrical circuit comprising a switch (3). An output voltage of a first power source (5), which is connected to the circuit, is measured and compared to a predefined threshold voltage. If the measured voltage is smaller than the threshold value it is determined that the switch (3) is in a closed state, and if the voltage is larger than the threshold value it is determined that the switch (3) is in an open state. The supply of power is controlled in accordance with the open/closed state of the switch (3). Preferably, the electrical circuit is connected to a second power source (9) when the switch (3) is in a closed state. Power is conserved while it is ensured that sufficient power is available when needed. The invention is very suitable for supplying power to a lamp (1) positioned inside a refrigeration compartment (2), especially when the system is battery powered.

Abstract: The present invention relates to a method for bringing a brushless motor, such as a multiphase brushless motor, operatively connected to for example a compressor into an optimal angular starting position in an energy saving manner, the method comprising the steps of applying a first drive voltage to a first phase winding of the motor and measuring a current flowing in another phase winding of said motor, said current being generated in response to the first drive voltage applied to the first phase winding. The method further comprises the step of switching the applied first drive voltage off when said current reaches a steady-state condition. By applying the method of the present invention a significant amount of power can be saved. The present invention further relates to a system for carrying out the present invention.

Abstract: The invention concerns a method for controlling a direct voltage source with a first direct voltage source (2) and a voltage monitoring device (24), which monitors an output voltage of the first direct voltage source (2) and acts upon a control device (31), the control device (31) controlling the working state of the first direct voltage source (2). Further, the invention concerns a voltage supply device (22) with which the method can be used. In this connection it is endeavored to reduce the risk of an increase in voltage in a circuit with several direct voltage sources. For this purpose, a second direct voltage source (3) produces a voltage change at the voltage monitoring device (24).

Abstract: A control system (12) for controlling a refrigeration system (17) comprising two or more compressors (13a, 13b) (e.g. a twin compressor system). Each compressor (13a, 13b) is connected to an electronic unit (14a, 14b), and the electronic units (14a, 14b) are adapted to communicate appropriate signals to each other when the corresponding compressor (13a, 13b) starts or stops operation. The electronics units (14a, 14b) are further adapted to control the operation of the corresponding compressor (13a, 13b) in response to a signal received from the other electronic unit (14a, 14b). Thereby the control system (12) is adapted to control the operation of the two or more compressors (13a, 13b) in a mutually dependent manner. When one compressor (13a, 13b) of a multi-compressor refrigeration system (17) stops operating, the remaining compressor(s) (13a, 13b) will build up a pressure difference between the pressure side and the suction side.

Abstract: A method and a control system for starting a motor (19), in particular a motor (19) for driving a compressor. The rotational speed (24) of the motor (19) is measured and compared to a minimum value. In the case that ?motor (24) is smaller than the minimum value after a predefined time interval has lapsed, the motor (19) is stopped, and the maximum current level to be supplied by the power source (18) is changed, preferably increased, before a new attempt to start the motor (19) is initiated. Preferably, the voltage (22) supplied to an electronic unit (21) is also measured, and in the case that it drops below a minimum voltage level, the motor (19) is stopped, and the maximum current level is changed, preferably decreased, before a new start attempt is initiated. It is possible to adjust the supplied current level in such a way that power is conserved while sufficient lubricated of the moving parts of the compressor is ensured.

Abstract: The invention relates to a device and method for supplying direct voltage, wherein said device comprises a first connection arrangement (3, 4) for a first direct voltage source (8) and a second connection arrangement (5, 6, 7) for a second direct voltage source (11), wherein the device (1) is provided with a protective element (18) which is connected to the first connection arrangement (3, 4) and prevents a charge equalisation between one direct voltage source (8, 11) and the other direct voltage source (11, 8). The aim of said invention is to ease the direct voltage supply (2) For this purpose the protective element (18) is also connected to the second connection arrangement (5, 6, 7) in order to prevent the defective operation of the device (1) in the case of the reversed polarity of the first direct voltage source (8).

Abstract: An electric circuit for supplying power to a DC application is disclosed. The electric circuit comprises a DC power source (1) connectable to an alternator charging circuit (2), an FET (T7), and a capacitor (8) connected across the gate terminal and the source terminal of the FET (T7). The drain terminal of the FET (T7) is connected to a negative terminal of the DC source (1). The FET (T7) protects the circuit against accidental connection of the alternator charging circuit (2) to the DC power source (1) with reversed polarity, by opening a switch (6) of the FET (T7) when this occurs. The capacitor (8) protects the FET (T7) from being pushed into avalanche in case a load-dump transient occurs. This is because the capacitor (8) in this case will charge and discharge, thereby introducing a time delay before the switch (6) is opened. Protection against load-dump transients is thereby obtained by means of a small component with low energy dissipation.

Abstract: A method for starting a battery driven motor, wherein an input voltage is measured continuously. In case the input voltage becomes smaller than a predefined minimum voltage the attempt to start the motor is stopped and the maximum permitted current level to be supplied from the battery to an electronic unit of the motor is lowered before the next attempt. This is repeated until the input voltage is larger than the minimum voltage and the motor is no longer in start-up mode. The method protects the battery from collapsing. The method is suitable for starting battery driven motors for driving compressors. The number of attempted start-up sequences may be counted and on the basis of this it may be determined that the battery is weak or that the wiring is misdimensioned. Furthermore, a control system for controlling starting of a motor.

Abstract: A method and a control unit for starting a compressor (3) in a refrigeration system (1) further comprising a condenser (2) and an evaporator (4). If an attempt to start-up the compressor (3) is unsuccessful a condenser cooling means, e.g. a fan, is started in order to provide cooling for the condenser (2). Thereby, if the temperature of the condenser is sufficiently high to cause an increased pressure on the condenser side of the compressor (3), cooling is provided for the condenser (2) in order to ensure a reliable start-up of the compressor (3). On the other hand, if the temperature of the condenser (2) is sufficiently low to ensure a reliable start-up of the compressor (3), cooling is not provided, thereby saving power while ensuring reliable start-up of the compressor (3).

Abstract: A method and a control unit (4) for controlling a supply of power to an electrical circuit comprising a switch (3). An output voltage of a first power source (5), which is connected to the circuit, is measured and compared to a predefined threshold voltage. If the measured voltage is smaller than the threshold value it is determined that the switch (3) is in a closed state, and if the voltage is larger than the threshold value it is determined that the switch (3) is in an open state. The supply of power is controlled in accordance with the open/closed state of the switch (3). Preferably, the electrical circuit is connected to a second power source (9) when the switch (3) is in a closed state. Power is conserved while it is ensured that sufficient power is available when needed. The invention is very suitable for supplying power to a lamp (1) positioned inside a refrigeration compartment (2), especially when the system is battery powered.

Abstract: A method and a control unit for controlling a power level being drawn from a power source (26). Based on a determined rate of change of a measured voltage (1) an estimated remaining runtime is calculated. The estimated remaining runtime represents a time where specific run criteria will no longer be fulfilled if the present power level is maintained. The estimated remaining runtime is compared to a threshold value, and in case the estimated remaining runtime is shorter than the threshold value, the power drawn from the power source (26) is decreased. Thereby the runtime for the power source (26) is maximised. This is particularly useful if the power source is a limited power source, such as a battery (26), e.g. for running a compressor (27) for a movable refrigeration system (24). The invention is suitable for automotive applications.

Abstract: A method and a control system for starting a motor (19), in particular a motor (19) for driving a compressor. The rotational speed (24) of the motor (19) is measured and compared to a minimum value. In the case that ?motor (24) is smaller than the minimum value after a predefined time interval has lapsed, the motor (19) is stopped, and the maximum current level to be supplied by the power source (18) is changed, preferably increased, before a new attempt to start the motor (19) is initiated. Preferably, the voltage (22) supplied to an electronic unit (21) is also measured, and in the case that it drops below a minimum voltage level, the motor (19) is stopped, and the maximum current level is changed, preferably decreased, before a new start attempt is initiated. It is possible to adjust the supplied current level in such a way that power is conserved while sufficient lubricated of the moving parts of the compressor is ensured.

Abstract: A method for starting a battery driven motor, wherein an input voltage is measured continuously. In case the input voltage becomes smaller than a predefined minimum voltage the attempt to start the motor is stopped and the maximum permitted current level to be supplied from the battery to an electronic unit of the motor is lowered before the next attempt. This is repeated until the input voltage is larger than the minimum voltage and the motor is no longer in start-up mode. The method protects the battery from collapsing. The method is suitable for starting battery driven motors for driving compressors. The number of attempted start-up sequences may be counted and on the basis of this it may be determined that the battery is weak or that the wiring is misdimensioned. Furthermore, a control system for controlling starting of a motor.