KR20000057322A - Measuring instrument for a loaded dc/dc converter - Google Patents

Abstract

PURPOSE: A measuring device for a loaded dc static converter is provided to produce a signal of reference-potential for the output current of the dc static converter through switching technique at small expenditure CONSTITUTION: A present invention pertains to a measuring instrument for a loaded dc/dc converter which converts an input potential(13), based on a reference potential(12), into two output potentials different from the reference potential(12). The output potentials can be harnessed at load connectors(21,22). A load(20) crossed by an output current(23) acts as a linkage between both load connectors(21,22). The output current(23) is harnessed as follows: a current(14) flowing into the dc/dc converter(10) against the reference potential(12) is recorded as a measure(25) of the output current(23) as compared with the reference potential.

Description

MEASURING INSTRUMENT FOR A LOADED DC / DC CONVERTER}

DE-OS 41 29 557 is known for lighting circuits for automotive light-emitting lamps and is designed so that the DC amplifier circuit is stored in the battery. The increased voltage in this way is an input value of the high frequency amplification circuit, and this input value serves as a light emitting lamp by the ignition circuit. This voltage amplification circuit is configured as a switched DC converter, in which one of the two output terminals is applied with the same input potential to become a so-called ground state. The output power of the voltage amplification circuit is sensed by the current measuring resistor installed in the ground line. The voltage drop across the measurement resistor is proportional to the output voltage and ground.

However, if the ground potential of one of the output terminals is different, the measuring device cannot maintain the measured voltage connected to ground itself. It is an object of the present invention to easily obtain an extension signal for an output voltage of a DC converter whose two output terminals receive a reference potential and other potentials. This object is attainable through the subject matter described in the dependent claims.

The present invention relates to a measuring device for a load DC converter according to the type of independent claim.

1 is a basic circuit diagram according to the present invention.

2 and 3 show other possible circuit wirings.

Unlike the prior art, the measuring device for a load DC converter according to the present invention generates a signal at a low cost by using a switching technology, so that the signal becomes a reference potential and becomes an output current value of the DC converter. As a result, there is no longer a costly measurement method for measuring the output line current. The measurement signal obtained by the above method can be input without, for example, an expensive current regulation processing operation. In addition, it can see the effect of generating the positive output voltage of the DC converter by itself. Therefore, excellent efficiency can be obtained. By properly dividing the voltage ratio, the requirements for the electrical components associated with the voltage can be reduced as well.

The methods described in the dependent claims enable a preferred reconfiguration of the device according to the invention. In the preferred reconstruction, the current reversed to the reference potential is sensed by the resistor. The voltage maintained as described above is proportional to the output power of the DC converter and becomes its reference potential. The voltage is an appropriate input value required for the regulating circuit.

According to another configuration, which serves the purpose of the device according to the invention, the capacitor is switched in parallel to the measuring resistor in order to bypass the dynamic current impulse. High frequencies generated during clock operation no longer interfere with the measurement signal associated with the reference potential. The AC voltage portion of the side current that was reversed to the reference potential is no longer applied to the measurement resistance.

Other arrangements according to the invention described in the other dependent claims are set out below.

The DC converter 10 has an input voltage 13 as an input value. The input voltage is applied to the input terminal 11 opposite the reference potential 12. In the DC converter 10, a current 14 flows in a reverse direction to the reference potential 12. The DC converter 10 applies the output current 23 flowing through the load 20 between the first output terminal 21 and the second output terminal 22 as an output value. The DC converter 10 applies the measurement voltage 25 connected to the reference potential 12 as another output value.

According to FIG. 2, the DC converter 10 applies an input voltage 13 connected to the reference potential 12 to the primary coil 33 of the transformer 29. At the common potential of the primary coil 33 and the power switch 32, the first output terminal as well as the first filter capacitor 38 switched to reverse the second reference potential 40 by the first diode 36. 21 works. The first connection terminal of the secondary coil 35 of the transformer 29 is connected to the reference potential 12 by the second diode 37, and the second connection terminal of the secondary coil 35 is the second output terminal. Not only (22) but also a second filter capacitor (39) connected to the reference potential (12) in reverse. The measurement current 14 flowing through the second diode 37 is sensed by the measurement resistor 30 in which the capacitor 31 is connected in parallel. The measurement resistor 30 and the capacitors 31 are disposed between the second diode 37 and the reference potential 12. The output value and the corresponding wiring are as shown in FIG.

In the DC converter 10 according to FIG. 3, the input voltage 13 which becomes the reference potential 12 (externally inputted to the reference potential 12) by the clocked power switch 32 has a transformer 29. It is configured to be applied to the first coil 41 of the. Here, the first connection terminal of the second coil 42 of the transformer 29 lies above the common potential of the first coil and the power switch 32. The second connection terminal of the second coil 42 connects the first output terminal 21 as well as the first filter capacitor 38 connected to return to the second reference potential 40 via the first diode 36. Operate. The first connection terminal of the third coil 43 of the transformer 29 is connected to the reference potential 12 via the second diode 37, and the second connection terminal of the third coil 43 is second It is connected not only to the output terminal 22 but also to the second filter capacitor 39 which is switched to counter the reference potential 12. The vertical capacitor 44 is switched between the first connection terminal of the third coil 43 and the second connection terminal of the second coil 42. In order to sense the current 14 flowing through the second diode 37, the measurement resistor 30 is switched between the second diode 37 and the reference potential 12, and the capacitor 31 is connected to the measurement resistor. Are arranged in parallel. Regarding the output value is as shown in FIG.

An embodiment operating method of the apparatus for a load DC converter according to the present invention is as follows.

The DC converter 10 converts the input voltage 13 which becomes the reference potential 12 into two output potentials, that is, potentials that can be detected by the output terminals 21 and 22. The input voltage 13 carries a battery, for example, where ground is used as the reference potential 12.

Basic circuit wirings of the DC converter 10 are known. Clocked voltage converters store energy in components for the purpose of increasing or decreasing the voltage. The components can be properly switched and standardized to perform the desired voltage conversion operation.

The load 20 is switched between the two output terminals 21 and 22. The role as the load 20 is, for example, a gas discharge lamp installed in an automobile. The direct current converter 10 operates here as a control circuit as well as an ignition circuit. The load 20 is not related to the reference potential 12.

The DC converter 10 applies the measurement voltage 25 as another output value. The measured voltage is input to the reference potential 12. This measurement voltage 25 is represented by the value of the output current 23 which will pass through the load 20. The measurement voltage 20 is maintained while the current 14 flowing back against the reference potential 12 is detected.

The circuit wiring according to FIG. 2 is in principle based on a positive blocking oscillator. Energy transfer is performed by a transformer 29 consisting of a primary coil 33 and a secondary coil 35. The transformer 39 is clocked by the power switch 32 on the primary side. As the power switch 32, for example, a power-MOS transistor is suitable. The bipolar blocking oscillator according to FIG. 2 differs from the conventional blocking oscillator in that the primary output terminal 21 is operated to the primary side by the primary diode 36. The load 20 stores energy when the power switch 32 is open. When the power switch 32 is closed, the transformer 29 operates as an intermediate memory. In other words, magnetic energy is charged.

When the power switch 32 is closed, an input voltage 13 is applied to the primary coil 33. The current flowing through the primary coil 33 induces a predetermined voltage to the secondary coil 35. The polarization of the secondary coil 35 is then performed such that the second diode 37 is polarized in the blocking oscillation direction. While the power switch 32 is closed, no current 14 flows against the reference voltage 12. Thus, the load 20 is not conductive via the first diode 36.

When the power switch 32 is open, the voltage induced in the secondary coil 35 is configured to change its polarity. This causes the second diode 37 to operate in the pass direction, allowing pulsed direct current to flow through the second diode. On the primary side, the load 20 is driven by the output current 23 by the first diode 36. The first filter capacitor 38 allows a direct current to flow in the load 20 by filtering the high frequency AC power portion.

The current 14 flowing through the second diode 37 in this phase becomes a value of the output current 23 flowing into the load 20. However, due to the association being the desired reference potential, the output current 23 is not detected directly by the measurement resistor but by the current 14 flowing inside the second diode 37. This role is played by the measurement resistor 30 which is switched between the second diode 37 and the reference potential 12. The measurement resistance 30 may be selected as a low resistance to prevent unnecessary waste. The value can be changed to a high millioohm-band, for example 100 mΩ. The capacitor 31 switched in parallel with respect to the measuring resistor 30 bypasses the measuring resistor 30 for the pulsed DC current. As a result, only the DC current component of the current 14 is detected through the measurement resistor 30. The measurement voltage 25 dropped to the measurement resistance 30 is thus the value of the output current 23 connected to the reference potential. The capacitor 31 is selectable for example in the micro-parad-band.

Similarly, a case may be considered in which a current flowing through the conductive wire placed at the reference potential 12 is sensed as the current 14. In this case, the measuring resistor 30 can be arranged between the power switch 32 and the diode 37, for example.

The circuit wiring according to Fig. 3 has a wiring structure similar to that described above. The wiring of FIG. 3 differs only in that the primary coil 41 is connected in series with the secondary coil 42 which is in connection with the tertiary coil 43 by the vertical condenser 44. In principle, the circuit wiring according to FIG. 3 operates like a conventional blocking oscillator, which means that the load 20 supplies energy when the power switch 32 is opened. The vertical capacitor 44 is charged when the power switch 32 is opened, so that a potential difference is generated between the secondary coil 42 and the tertiary coil 43. When the power switch 32 is closed, the current flows in the reverse direction to the reference potential 12 through the primary coil 41. Since the diode is not polarized in the blocking direction, no current flows through the second diode 36 while the power switch 32 is closed. When the power switch 32 is closed, the secondary filter condenser 39 and the vertical condenser 44 are placed horizontally and parallel. Energy stored in the vertical condenser 44 is recharged by the second vertical condenser 39. The output current 23 flows inside the capacitors 38, 39, 44 during this time.

When the power switch 32 is opened, the polarities of the coils 41, 42, and 43 are changed. In the tertiary coil 43, a voltage to the second diode 37 is formed. The output current 23 flows through the load 20 by the first diode 36, and the current 14 flows back to the reference potential 12 through the second diode 37. At the same time the vertical condenser 44 is charged. The charging current flows through the second diode 37.

Magnetic power is transmitted when the power switch 32 is opened. The voltage dropped on the tertiary coil 43 is charged in the second filter capacitor 39. The coils 41, 42 and 43 must be well connected for this. The number of windings of the primary coil 41 and the secondary coils 42 should add up to the number of windings of the tertiary coil 43.

In the switched-on state, since the vertical capacitor 44 is switched in parallel with the second filter capacitor 39 so that energy is transferred, the capacity of the vertical capacitor 44 is determined by the switching on / off time of the power switch 32. Depends on the length.

The current 14 flowing through the second diode 37 is sensed by the measuring resistor 30 with the capacitor 31 switched in parallel, similar to the circuit wiring according to FIG. 2. The measured voltage 25 obtained as described above enters the reference potential 12.

In addition, as the current 14, a case where a current flowing through the conductive wire placed on the reference potential 12 is sensed may be considered. The measuring resistor 30 can be arranged, for example, between the power switch 32 and the diode 37.

The measuring principle referring to the reference potential is not limited only to the circuit wiring according to FIG. 2 or 3. Thus, for example, a sensing operation for operating the second diode 36 may be performed between the first and second coils 41 and 42. In addition, the measuring device is not limited to the blocking oscillator, so that the measuring method can be applied to the flow transducer or the conventional conventional DC converter, that is, the converters to which the output potential different from the reference potential 12 is applied.

Claims (8)

In the DC converter converting the input voltage 13, which becomes the reference potential 12, into output potentials that can be detected at two or more of the reference potentials 12 and other output terminals 21, 22, the output current 23 In the measuring device for the load DC converter 10 is configured such that the reference potential 12 is sensed by connecting the output terminals 21 and 22 with a load 20 flowing thereto. A measuring device for a load DC converter, characterized in that a current (14) flowing in the DC converter (10) against the reference potential (12) is sensed as a value (25) that becomes a reference potential for the output current (23). The measuring device for a load direct current converter according to claim 1, wherein a current (14) flowing backward to the reference potential (12) is sensed by a measurement resistor (30). The measuring device for a load DC converter according to claim 2, wherein the capacitor (31) is switched in parallel to the measuring resistor (30) so as to bypass the dynamic current impulse. 4. An input voltage (13) which becomes the reference potential (12) is applied to the primary coil (33) of the transformer (29) by a clocked power switch (32). Become, As the common potential of the primary coil 33 and the power switch 32, the first filter capacitor 38, which is switched to reverse the second reference potential 40 by the first diode 36, is a first output terminal. Works as in (21), The first connection terminal of the secondary coil 35 of the transformer 29 is connected to the reference potential 12 by the second diode 37, the second connection terminal of the secondary coil 35 is the second Measuring device for load DC converter, characterized in that connected to the output terminal 22 and the second filter capacitor (39) switched to reverse the reference potential (12). The input voltage (13) according to any one of claims 1 to 3, wherein the primary coil (41) of the transformer (29) becomes the reference potential (12) by a power switch (32) receiving a clock signal. Is authorized, The first connection terminal of the secondary coil 42 of the transformer 29 receives the common potential of the primary coil 41 and the power switch 32, and the second connection terminal of the secondary coil 42 The first filter capacitor 38 and the second output terminal 21 switched by the first diode 36 to reverse the second reference potential 40 are operated. The first connection terminal of the tertiary coil 43 of the transformer 29 is connected to the reference potential 12 by a second diode 37 and the second connection terminal of the tertiary coil 43 is of a second output. Connected with a second filter capacitor 39 which is switched to counter the terminal 22 and the reference potential 12, Measurement device for a load DC converter, characterized in that the vertical capacitor (44) is switched between the first connection terminal of the tertiary coil (43) and the second connection terminal of the secondary coil (42). The measuring device for a load DC converter according to claim 4 or 5, wherein the measuring resistor (30) parallel to the capacitor (31) connects the second diode (37) with a reference potential (12). A measuring device for a load DC converter according to claim 4 or 5, characterized in that the measuring resistor (30) parallel to the capacitor (31) is switched between the second diode (37) and the power switch (32). The measuring device for a load DC converter according to any one of claims 1 to 7, which is used for a gas discharge lamp.