Monitoring supply voltage system for electronic component and network monitoring circuit

Abstract

A monitoring system for monitoring a supply voltage for an electronic component is described, comprising a voltage monitoring unit, which is configured to monitor a voltage level assigned to a supply voltage applied to the electronic component, and a switching unit which is configured to switch the electronic component on and/or off. The switching unit is coupled with the voltage monitoring unit. The switching unit is furthermore configured to switch off the electronic component if the voltage monitoring unit determines that the voltage level is below a predetermined threshold value. A mains monitoring circuit is furthermore described.

Claims

1. A monitoring system for monitoring a supply voltage for an electronic component, comprising: a voltage monitoring unit which is configured to monitor a voltage level assigned to the supply voltage applied to the electronic component, and a switching unit which is configured to switch the electronic component on and/or off, wherein the switching unit is coupled with the voltage monitoring unit, wherein the switching unit is configured to switch the electronic component off when the voltage monitoring unit determines that the voltage level is below a predetermined threshold value, wherein the monitoring system includes a sensor which monitors a pressure of a system including the electronic component, and wherein the monitoring system is configured to indirectly identify the pressure via a temperature.

2. The monitoring system according to claim 1, wherein the monitoring system is configured to detect the time span during which the voltage level is below the predetermined threshold value.

3. The monitoring system according to claim 2, wherein the switching unit is configured to switch off the electronic component if when the detected time span is longer than a predetermined time span.

4. The monitoring system according to claim 1, wherein the switching unit is configured to switch off the electronic component for a specified period of time and/or to switch the electronic component on again.

5. The monitoring system according to claim 1, wherein the voltage monitoring unit is configured to check the voltage level again after the switching off of the electronic component.

6. The monitoring system according to claim 1, wherein the switching unit is configured to switch the electronic component on again when the system parameter detected by the sensor falls below and/or reaches a specified parameter value.

7. The monitoring system according to claim 1, wherein the electronic component is a compressor working against a load, in particular a mechanical load, and is in particular an air-conditioner compressor.

8. A mains monitoring circuit for a monitoring system according to claim 1, including two mains connections for a mains voltage, and a comparator, wherein the mains monitoring circuit comprises includes a reference voltage circuit section which generates a reference voltage applied to the comparator from the mains voltage, in particular wherein the reference voltage circuit section comprises includes a capacitor, wherein the mains monitoring circuit includes a supply voltage circuit section for the comparator which generates an operating voltage for the comparator from the mains voltage.

9. The mains monitoring circuit according to claim 8, wherein a rectifier bridge assigned to the two mains connections is provided, the bridge outputs of which are each assigned to the reference voltage circuit section, in particular wherein a low-pass filter and/or a diode (38) for stabilizing the rectified voltage is/are provided between a bridge output and the reference voltage circuit section.

10. The mains monitoring circuit according to claim 8, wherein the output of the comparator is assigned to a microcontroller and/or to an optocoupler, in particular wherein the microcontroller is assigned to a switching element in terms of control.

11. A monitoring system for monitoring a supply voltage for an electronic component, comprising: a voltage monitoring unit which is configured to monitor a voltage level assigned to the supply voltage applied to the electronic component, and a switching unit which is configured to switch the electronic component on and/or off, wherein the switching unit is coupled with the voltage monitoring unit, wherein the switching unit is configured to switch the electronic component off when the voltage monitoring unit determines that the voltage level is below a predetermined threshold value, wherein the monitoring system is an air-conditioning system and the electronic component is an air-conditioner compressor, and wherein the air-conditioning system includes the air-conditioner compressor that is transferred into its initial state, such that the next time the air-conditioning system is in its operation or started state, a typical initial state is then present for which the air-conditioner compressor or the entire air-conditioning system is designed, due to pressure in the air-conditioning system is sufficiently reduced so that the air-conditioner compressor can subsequently be started without any difficulty.

Description

(1) Further advantages and characteristics of the invention will become apparent from the description below and from the drawings to which reference is made and in which:

(2) FIG. 1 shows a schematic representation of a monitoring system according to the invention in an air-conditioning system,

(3) FIG. 2 shows a circuit diagram of a monitoring system according to the invention,

(4) FIG. 3 shows a schematic representation of a monitoring system according to the invention in any electronic component,

(5) FIG. 4 shows a circuit diagram of a mains monitoring circuit according to the invention in one embodiment, which is provided for a monitoring system according to the invention, and

(6) FIG. 5 shows a diagram showing the occurring voltages.

(7) FIG. 1 schematically shows a monitoring system 10 provided for monitoring a supply voltage. An electronic component 14 present in a system 12 is operated via the supply voltage.

(8) In the embodiment shown, the monitoring system 10 is assigned to a system 12 designed as an air-conditioning system, which is shown only schematically in its essential features. In the representation, the monitoring system 10 monitors the supply voltage of an electronic component 14 designed as an air-conditioner compressor.

(9) All in all, the electronic component 14 configured as an air-conditioner compressor, a condenser 2, a dryer 4, an evaporator 6, an expansion device 8, form a cooling circuit that implements the cooling function of the system 12, which is designed as an air-conditioning system.

(10) To this end, the monitoring system 10 comprises a voltage monitoring unit 16 which is configured to monitor a voltage level assigned to the supply voltage applied to the electronic component 14, i.e. the air-conditioner compressor.

(11) The monitoring system 10 also includes a switching unit 18, which is configured to switch the electronic component 14, i.e. the air-conditioner compressor, on or off. The switching unit 18 switches the electronic component 14 off, in particular when the voltage monitoring unit 16 determines that the voltage level falls below a predetermined threshold value.

(12) For this purpose, the switching unit 18 is coupled with the voltage monitoring unit 16 in terms of control so that the switching unit 18 can receive a control signal of the control monitoring unit 16.

(13) In the embodiment shown, the monitoring system 10 additionally comprises a sensor 20 which monitors a system parameter of the system 12, i.e. of the air-conditioning system.

(14) In the embodiment shown, the system parameter may be a pressure. The system parameter detected by the sensor 20 is transmitted to the switching unit 18 which thus receives a signal from the voltage monitoring unit 16 and a signal from the pressure sensor 20.

(15) The pressure can also be determined by the monitoring system 10 indirectly via a temperature.

(16) Generally, the switching unit 18 is configured to switch the electronic component 14 on or off, which is carried out depending on the received signals, as will be explained in more detail below.

(17) As already explained, the electronic component 14 is switched off by the switching unit 18 if the voltage level has fallen below the predetermined threshold value.

(18) Similarly, the electronic component 14 is switched on by the switching unit 18 if the voltage level has increased above a predetermined threshold value and—depending on the configuration—the system parameter, for example, reaches a suitable value and/or a sufficient large time has elapsed after the switching off.

(19) If the monitoring system 10, as is the case in the embodiment shown, comprises the sensor 20 which monitors a system parameter, the switching unit 18 additionally takes the detected system parameter into account.

(20) For example, the pressure in the air-conditioning system 12 should fall below and/or should have reached a specified pressure value before the switching unit 18 switches the electronic component 14 on again. This is carried out to ensure that the electronic component 14, i.e. the air-conditioner compressor does not have to operate against the pressure still present in the air-conditioning system 12, which would result to a high current consumption.

(21) Generally, the switching unit 18 is configured to switch off the electronic component 14 only if the voltage level falls below the predetermined threshold value for a certain time.

(22) This means that the monitoring system 10 is configured to detect the time span during which the voltage level is below the predetermined threshold value. If the time span is longer than a predetermined time span, the switching unit 18 switches the electronic component 14 off. It is thus ensured that short-time voltage dips which the system 12, in particular the electronic component 14, can tolerate, do not lead to the switching off of the corresponding electronic component 14. The system stability is therefore increased.

(23) Furthermore, the switching unit 18 is configured to switch off the electronic component 14 for a specified period of time so that the electronic component 14 is (automatically) switched on again only after the specified period of time has elapsed. This is intended to ensure that the system 12 can return in its initial state as is the case during normal operation. More specifically, the pressure present in the system 12 is to be reduced so that the electronic component 14 does not have to be started against this pressure.

(24) Alternatively or additionally, it may be provided that the switching unit 18 does not switch the electronic component 14 on again until it receives an appropriate control signal, for example from the voltage monitoring unit 16 and/or from the sensor 20.

(25) If the appropriate control signal is output by the voltage monitoring unit 16 already before the specified period of time has elapsed, it may be provided that the specified period of time is waited for first.

(26) If an appropriate control signal is output by the sensor 20, the electronic component 14 can be directly restarted as the desired initial state of the system 12 should have been restored.

(27) Generally, the voltage monitoring unit 16 is configured to check the voltage level again after the electronic component 14 has been switched off. The voltage monitoring unit 16 monitors the voltage level continuously.

(28) The electronic component 14 is not switched on again before the voltage level is above the predetermined threshold value.

(29) FIG. 2 illustrates the monitoring system 10 on the basis of a circuit diagram which shows the structure of the mains monitoring circuit 22 of the monitoring system 10. The monitoring system 10 thus comprises the mains monitoring circuit 22.

(30) The mains monitoring circuit 22 includes two mains connections 24, 26 to which the mains voltage for the electronic component 14 is applied.

(31) The mains voltage to be monitored is first converted to a voltage level which ensures that the remaining components of the mains monitoring circuit 22 remain undamaged by means of a voltage divider 28 which includes two ohmic resistors. In this respect, the mains voltage to be monitored and the voltage level are linked to or associated with each other.

(32) A rectifier bridge 30 adjoins the voltage divider 28 and is thus assigned to the two mains connections 24, 26. The rectifier bridge 30 ensures that no negative voltages have to be processed by the mains monitoring circuit 22, as only positive half-waves are allowed to pass.

(33) The rectifier bridge 30 includes two bridge outputs 32, 34 so that a rectified voltage is output.

(34) A first low-pass filter 36 and a diode 38 for stabilizing the rectified voltage are assigned to the first bridge output 32.

(35) The stabilized and rectified voltage is then provided for a reference voltage circuit section 40 which generates and provides a reference voltage, as will be explained below.

(36) The reference voltage circuit section 40 comprises a resistance 42, a capacitor 44 and a diode 46 connected in parallel to the capacitor 44. In the illustrated embodiment, the diode 46 is in particular a Zener diode. The components of the reference voltage circuit section 40 are assigned to the outputs 32, 34 of the rectifier bridge 30. The rectifier bridge 30 is in turn coupled with the mains voltage to be monitored, such that the reference voltage is generated from the mains voltage to be monitored. In this respect, the reference voltage circuit section 40 may also be referred to as integrated reference voltage source.

(37) The reference voltage circuit section 40 is adjoined by a comparator 48 to which the reference voltage generated by the reference voltage circuit section 40 is applied correspondingly, more specifically to the negative input 50 of the comparator 48.

(38) In contrast thereto, the positive input 52 of the comparator 48 is assigned to the voltage level to be monitored.

(39) The positive half-waves which are generated by the rectifier bridge 30 and are supplied to the positive input 52 of the comparator 48, are also appropriately processed by a voltage divider 54 which includes two resistors, and by a low-pass filter 56 and a diode 58 (which is a Zener diode in the illustrated example embodiment), so that an overvoltage protection is ensured.

(40) Furthermore, the mains monitoring circuit 22 comprises a supply voltage circuit section 60 which, among other things, generates an operating voltage for the comparator 48 from the mains voltage to be monitored, so that the comparator 48 is operated via the mains voltage to be monitored.

(41) In the embodiment shown, the output 62 of the comparator 48 is assigned to a microcontroller 64 via which a switching element 66 configured as a transistor in the configuration shown is driven.

(42) The switching element 66, i.e. the transistor, controls the electronic component 14 accordingly via a relay 68, such that the electronic component 14 is switched on or off.

(43) Furthermore, the microcontroller 64 is coupled with the sensor 20 such that the system parameter detected by the sensor 20 is also transmitted to the microcontroller 64.

(44) The signal output by the sensor 20 is forwarded to the microcontroller 64 in a filtered manner via a low-pass filter 70.

(45) Similarly, a low-pass filter 72 may be provided between the comparator 48 and the microcontroller 64.

(46) In this respect, the monitoring system 10 for monitoring a supply voltage for an electronic component 14 comprises the mains monitoring circuit 22.

(47) In the embodiment shown, the voltage monitoring unit 16 can be formed through the components of the mains monitoring circuit 22 up to the output 62 of the comparator 48, i.e. through the comparator 48 and the reference voltage circuit section 40. In contrast thereto, the switching unit 18 of the monitoring system 10 is formed by the microcontroller 64 and the assigned switching element 66, via which the voltage supply of the electronic component 14 can be switched on or off.

(48) To this end, the switching unit 18, in particular the microcontroller 64, receives a control signal from the comparator 48 and also from the sensor 20, on the basis of which the microcontroller 64 drives the assigned switching element 66 accordingly.

(49) FIG. 3 shows a schematic representation of a general use of the monitoring system 22, the electronic component 14 being a motor of any type.

(50) The electronic component 14 is supplied with an electrical voltage by an electrical mains supply 73. Furthermore, a fuse F and a switch S which is here controlled by the relay 68, as will be explained below, are present.

(51) The mains monitoring circuit 22 monitors the voltage supplied via the electrical mains supply 73, as is schematically shown in FIG. 3, and, in case of a voltage dip an/or a voltage interruption, transmits a signal to a control logic which is here configured as the microcontroller 64 by way of example.

(52) In case of a dropping below the reference voltage beyond the specified period of time, the switch S is opened by the microcontroller 64 via the relay 68, and thus the voltage supply of the electronic component 14 is interrupted. For switching the electronic component 14 on, i.e. for the new closing of the switch S, the microcontroller 64 is here connected to the sensor 20 which provides a statement concerning the system parameter.

(53) Alternatively or additionally, the time is also awaited during which the electronic component 14 should be switched off, so that the initial state is restored. By taking the system parameter and/or the duration of being switched-off, i.e. the duration of the switched-off state into account, it is assumed that the voltage level required by the electronic component 14 for restarting falls below the level, which cause the fuse F to blow, within a tolerable time, and/or that the required current demand does not remain at such a high level so long that the fuse F would blow.

(54) FIG. 4 shows an alternative embodiment of the mains monitoring circuit 22 in which in addition to the embodiment shown in FIG. 2, an optocoupler 74 is provided which is arranged between the output 62 of the comparator 48 and the microcontroller 64 to provide a galvanic isolation. In this respect, the optocoupler 74 provides a galvanic isolation of the voltage monitoring unit 16 and the switching unit 18 of the monitoring system 10.

(55) FIG. 5 shows an exemplary diagram showing the voltages processed by means of the monitoring system 10 or the mains monitoring circuit 22. The circuit of FIG. 4 is considered here, in which an inversion of the signal of the comparator 48 is achieved due to the optocoupler 74 used, in contrast to the circuit of FIG. 2.

(56) A supply voltage 76 provided as an alternating voltage is shown, which results in a voltage level 78 which is applied to the positive input 52 of the comparator 48 and is compared with the reference voltage 80 generated from the supply voltage 76, which represents the predetermined threshold value and is applied to the negative input 50 of the comparator 48.

(57) FIG. 5 shows that the supply voltage 76 decreases over the time as a result of which the voltage level 78 also decreases.

(58) As soon as the voltage level 78 falls below the reference voltage 80 or the predetermined threshold value, the output voltage 82 at the output 62 of the comparator 48, i.e. the output signal thereof changes, such that the signal 82 is produced behind the optocoupler 74 and thus for the microcontroller 64. As a result of this and the inversion due to the optocoupler 74, a control signal is output which is supplied to the microcontroller 64.

(59) The microcontroller 64 can then be configured to detect the time span, how long the voltage level 78 is below the predetermined threshold value 80, in that the microcontroller 64 measures how long it receives the “high signal” of the mains monitoring circuit 22—i.e. the inverted signal of the comparator 48.

(60) If the detected time span is longer than a predetermined time span stored in the microcontroller 64, the microcontroller 64 controls the assigned switching element 66 to switch out the electronic component 14.

(61) Furthermore, the microcontroller 64 can be configured to as to maintain the electronic component 14 in the switched-off state for a specified period of time which is also stored in the microcontroller 64, even if a “low signal” is again output by the mains monitoring circuit 22. The microcontroller 64 does not control the switching element 66 again before the specified period of time has elapsed.

(62) Furthermore, the microcontroller 64 can receive the corresponding signal from the sensor 20, on the basis of which the microcontroller 64 drives the switching element 66 to switch the electronic component 14 on again.

(63) The comparator 48 and thus the voltage monitoring unit 16 continuously monitors the voltage level 78, as can be seen from the diagram of FIG. 5, so that it is immediately recognized when the voltage level 78 is below or above the predetermined threshold value or the constant reference voltage 80.