Power supply unit

Abstract

The present disclosure relates to a power supply unit having: an output for outputting an output current and an output voltage; and a protective element having a signal output path, wherein the protective element is connected downstream of the output and designed to maintain the signal output path when the output current exceeds a first amplitude threshold value and to interrupt the signal output path when the output current exceeds a second amplitude threshold value, the second amplitude threshold value being higher than the first amplitude threshold value; wherein the power supply unit is designed to reduce an amplitude of the output voltage and to increase an amplitude of the output current above the second amplitude threshold value, in order to interrupt the signal output path, when the output current exceeds the first amplitude threshold value.

Claims

1. A power supply unit, comprising: an output configured to deliver an output current and an output voltage; and a protective element having a signal output path, wherein the protective element is connected downstream of the output and is configured to maintain the signal output path when the output current exceeds a first amplitude threshold value and to interrupt the signal output path when the output current exceeds a second amplitude threshold value, the second amplitude threshold value being higher than the first amplitude threshold value, wherein the power supply unit is configured to reduce an amplitude of the output voltage and to increase an amplitude of the output current above the second amplitude threshold value, in order to interrupt the signal output path when the output current exceeds the first amplitude threshold value.

2. The power supply unit according to claim 1, wherein the power supply unit is configured to increase the amplitude of the output voltage following the reduction when the amplitude of the output current is below a third amplitude threshold value following expiration of a predetermined time interval.

3. The power supply unit according to claim 1, wherein the power supply unit is configured to again reduce the amplitude of the output voltage when the amplitude of the output current is above the third amplitude threshold value following expiration of the predetermined time interval.

4. The power supply unit according to claim 1, further comprising a measuring device configured to measure the amplitude of the output current.

5. The power supply unit according to claim 1, further comprising a control device configured to set the amplitude of the output current or of the output voltage.

6. The power supply unit according to claim 1, wherein the protective element comprises a line circuit breaker with electromagnetic triggering.

7. The power supply unit according to claim 1, wherein the protective element comprises a melting fuse.

8. The power supply unit according to claim 1, wherein the protective element comprises a cold-conductor resistance.

9. The power supply unit according to claim 1, wherein the protective element is disposed in a housing of the power supply unit and wherein an additional output configured to deliver the output current and the output voltage is connected downstream of the protective element, (103), wherein the signal output path is disposed between the output and the additional output.

10. The power supply unit according to claim 1, further comprising a user interface configured to set or pre-store one or more of: the first amplitude threshold value, the second amplitude threshold value, or the third amplitude threshold value, amplitude threshold value.

11. The power supply unit according to claim 10, wherein the user interface comprises a communications interface or an actuating element configured to set the respective amplitude threshold value.

12. The power supply unit according to claim 1, wherein the power supply unit is configured to set the amplitude of the output voltage or the amplitude of the output current based on an amplitude value of a supply voltage of the power supply unit in order to reduce an electric power uptake of the power supply unit.

13. A method for supplying a consuming device with electrical energy by means of a power supply unit, comprising: measuring an amplitude of an output current of a power supply unit; and reducing an amplitude of an output voltage of the power supply unit and increasing the amplitude of the output current above a second amplitude threshold value when the output current exceeds a first amplitude threshold value, in order to trigger a protective element, connected downstream of an output of the power supply unit, to interrupt a signal output path of the protective element; wherein the protective element is configured to maintain the Rail signal output path when the output current exceeds the first amplitude threshold value and to interrupt the signal output path when the output current exceeds a second amplitude threshold value, wherein the second amplitude threshold value is higher than the first amplitude threshold value.

14. The method according to claim 13, further comprising: increasing the amplitude of the output voltage if the amplitude of the output current is below a third amplitude threshold value following expiration of a predetermined time interval.

15. The method according to claim 13, further comprising: reducing again the amplitude of the output voltage, if the amplitude of the output current is above the third amplitude threshold value after expiration of the predetermined time interval.

16. The method of claim 13, further comprising: setting or pre-storing one or more of: the first amplitude threshold value, the second amplitude threshold value, or the third amplitude threshold value.

17. The method of claim 13, further comprising: setting the amplitude of the output voltage or the amplitude of the output current based on an amplitude value of a supply voltage of the power supply unit in order to reduce an electric power uptake of the power supply unit.

18. The power supply unit of claim 4, wherein the measuring device comprises a shunt or a Hall probe.

19. The power supply unit of claim 4, wherein the measuring device is incorporated into a microcontroller of the power supply unit.

20. The power supply unit of claim 5, wherein the control device comprises a potentiometer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Examples of the principles of this disclosure are illustrated in the drawings, and will be described in more detail herein below.

(2) FIG. 1 shows a schematic diagram of a power supply unit;

(3) FIG. 2 shows a schematic diagram of a method of supplying a consuming device with electrical energy by means of a power supply unit;

(4) FIG. 3 shows an arrangement for supplying a consuming device with electrical energy by means of a power supply unit; and

(5) FIG. 4 shows plots of an output voltage and an output current of a power supply unit for supplying a consuming device with electrical energy.

DETAILED DESCRIPTION

(6) FIG. 1 illustrates a schematic diagram of a power supply unit 100 according to an example of the principles of this disclosure. The power supply unit 100 is comprised of an output 101 and a protective element 103 with a signal output path 105.

(7) The power supply unit 100 is designed having: the output 101 for delivering an output current and an output voltage; and the protective element 103 with the signal output path 105, which protective element 103 is connected downstream of the output 101 and is designed such that when the output current exceeds a first amplitude threshold value the signal output path 105 is maintained, and when the output current exceeds a second amplitude threshold value the signal output path 105 is interrupted, with the second amplitude threshold value being higher than the first amplitude threshold value, wherein the power supply unit 100 is designed to reduce an amplitude of the output voltage, and to increase an amplitude of the output current above the second amplitude threshold value, when the output current exceeds the first amplitude threshold value, so as to interrupt the signal output path 105.

(8) The power supply unit 100 may be an electric power supply unit such as a voltage supply device or a current supply device. Further, the power supply unit 100 may comprise a measuring device for measuring the amplitude of the output voltage, and/or a control device for adjusting the amplitude of the output current and or the amplitude of the output voltage. For example, the power supply unit 100 comprises a microcontroller in which the measurement device and/or the control device are integrated, and which furthermore is designed to recognize if the measured amplitude of the output current exceeds the first amplitude threshold value.

(9) The protective element 103 may comprise a melting fuse, a line circuit breaker, e.g. a line circuit breaker with electromagnetic triggering, and/or a cold-line resistance.

(10) The first amplitude threshold value of the output current may be a first threshold value pre-stored in a memory of the power supply unit 100. The first threshold value is, e.g., 0.01, 0.1, 1, 3, 5, 6, 8, 10, 12, 16, 20, 30, 40, 50, 75, 100, or 200 amps. Furthermore, the second amplitude threshold value of the output current may be a second threshold value pre-stored in a memory of the power supply unit 100. The second threshold value is, e.g., 0.01, 0.1, 1, 3, 5, 6, 8, 10, 12, 16, 20, 30, 40, 50, 75, 100, or 200 amps. The second amplitude threshold value of the output current may be at a value which corresponds to twice, three times, four times, five times, six times, seven times, eight times, nine times, or ten times the amplitude of the nominal output current of the power supply unit 100. The amplitude of the output voltage may be at 0.001, 0.01, 0.1, 1, 5, 10, 12, 15, 20, 24, 30, 40, 50, 75, 100, 250, 500, or 1000 volts.

(11) FIG. 2 illustrates a schematic diagram of a method 200 for supplying a consuming device with electrical energy by means of a power supply unit 100. The method 200 comprises the method steps of measuring 201, reducing 203, and increasing 205.

(12) The method 200 for supplying a consuming device with electrical energy by means of a power supply unit 100, wherein a protective element 103 with a signal output path 105 is connected downstream of an output 101 of the power supply unit 100 for supplying an output current and an output voltage, wherein the protective element 103 is designed to maintain the signal output path 105 when the output current exceeds a first amplitude threshold value, and to interrupt the signal output path 105 when the output current exceeds a second amplitude threshold value, wherein the second amplitude threshold value is higher than the first amplitude threshold value, comprising: measuring 201 an amplitude of the output circuit, reducing 203 an amplitude of the output voltage, and increasing 205 the amplitude of the output current above the second amplitude threshold value when the output current exceeds the first amplitude threshold value, in order to interrupt the signal output path 105.

(13) FIG. 3 illustrates an arrangement 300 for supplying a consuming device 303 with electrical energy by means of a power supply unit 100. Furthermore, a supply voltage U.sub.IN, an output voltage U.sub.OUT, a line resistance 301, and a malfunction 305 of the consuming device 303 are illustrated.

(14) The power supply unit 100 is supplied with the supply voltage U.sub.IN, and delivers the output voltage U.sub.OUT to power the consuming device 303. In the event of a malfunction 305 of the consuming device 303, such as a short circuit, a defect, or a failure, the output current corresponding to the output voltage U.sub.OUT can be delivered, via the line resistance 301 of the electrical connecting line and the short circuit resistance or overload of the consuming device 303. When the said corresponding output current exceeds the first amplitude threshold value, the power supply unit 100 can reduce the amplitude of the output voltage U.sub.OUT and can raise an amplitude of the corresponding output current above the second amplitude threshold value, in order to interrupt the signal output path 105.

(15) The line resistance 301 may be 1, 5, 10, 25, 50, 75, 100, 125, 150, 175, or 200 milliohms.

(16) According to an example, an electric power or energy of the power supply unit 100 can be drawn in a regulated fashion via a power path of the power supply unit 100, instead of drawing the electric power or energy via non-regulable output capacitors. E.g. the electric power (or energy) may be drawn directly from the powering network of the power supply unit 100, in particular via the supply voltage U.sub.IN.

(17) FIG. 4 shows plots of an output voltage U.sub.OUT and of an output current I.sub.OUT, of a power supply unit 100 for supplying electrical energy to a consuming device 303. A first output voltage plot 401, a second output voltage plot 403, and a third output voltage plot 405, of the output voltage U.sub.OUT, as a function of time t, are shown. Also a first output current plot 407 and a second output current plot 409, of the output current I.sub.OUT, as a function of time are shown.

(18) In the first output voltage plot 401, the output voltage U.sub.OUT is permanently set to a nominal output voltage U.sub.NOM. If at the first time point t.sub.1 a malfunction 305, such as a short circuit, occurs in the consuming device 303, the output current I.sub.OUT following the first output plot 407 can be increased to a maximum output current I.sub.1, in order to interrupt the signal output path 105. The maximum output current I.sub.1 may be limited by the line resistance 301 of the electrical connecting line and the short circuit resistance or overload of the consuming device 303. If at the second time point t.sub.2 the signal output path 105 is interrupted or if a protective element 103, e.g. a fuse, which is connected in series with the consuming device 303, is triggered, then the output current I.sub.OUT may be reduced.

(19) In the second output voltage plot 403, the output voltage U.sub.OUT is set to the nominal output voltage U.sub.NOM at the start. If at the first time point t.sub.1 a malfunction 305, such as a short circuit, occurs in the consuming device 303, the output current I.sub.OUT following the second output plot 409 may be increased to a maximum output current I.sub.1, in order to interrupt the signal output path 105, while the output voltage U.sub.OUT is reduced. The maximum output current I.sub.1 may be limited by the line resistance 301 of the electrical connecting line and the short circuit resistance or overload of the consuming device 303. If at the second time point t.sub.2 the signal output path 105 is interrupted or if a protective element 103, e.g. a fuse, which is connected in series with the consuming device 303, is triggered, then the output current I.sub.OUT may be reduced to the nominal output current I.sub.2, and the output voltage U.sub.OUT may be increased to the nominal output voltage U.sub.NOM.

(20) In the third output voltage plot 403, the output voltage U.sub.OUT is set to the nominal output voltage U.sub.NOM at the start. If at the first time point t.sub.1 a malfunction 305, such as a short circuit, occurs in the consuming device 303, the output current I.sub.OUT following the first output plot 407 can be increased to a maximum output current I.sub.1, in order to interrupt the signal output path 105. The maximum output current I.sub.1 may be limited by the line resistance 301 of the electrical connecting line and the short circuit resistance or overload of the consuming device 303. If at the second time point t.sub.2 the signal output path 105 is not interrupted or if a protective element 103, e.g. a fuse, which is connected in series with the consuming device 303, is not triggered, e.g. because the maximum output current I.sub.1 is less than the second amplitude threshold value, then the output voltage U.sub.OUT may be reduced further, and a short circuit current can be established in the power supply unit 100. This may be the case, e.g., if no fuse or a too large fuse is connected upstream of the consuming device 303.

(21) According to one example, the increasing 205 of the output current I.sub.OUT to the maximum output current I.sub.1 may be carried out repeatedly, in order to eventually interrupt the signal output path 105 in one of the repetitions. A recovery time may be provided between the repetitions, e.g. equal to the additional predetermined time interval, for cooling of the components.

(22) According to another embodiment, the plots may be analogously valid or apply for a current-supply unit, with the terms voltage and current being interchanged.

(23) According to yet another embodiment, when a malfunction 305 occurs under circumstances of a low line resistance 301 of the electrical connecting line and a low short circuit resistance or a low overload of the consuming device 303, a higher output current I.sub.OUT or peak current may be set, if a capacitance is connected in parallel to the output 101. On the other hand, if the short-time current increases with reducing 203 of the output voltage U.sub.OUT, the output current I.sub.OUT can be limited.

(24) According to still another example, standard consuming devices connected in parallel to the consuming device 303 can bridge over the reducing 203 of the output voltage U.sub.OUT for a short period of time, e.g. a few milliseconds. E.g., the standard EN 61131 for memory-programmable control devices requires a time period of 10 msec.

(25) In another example, a line circuit breaker with magnetic triggering may interrupt a signal output path associated with the line circuit breaker within 10 msec, or may trigger it within 10 msec. Accordingly, a line circuit breaker with magnetic triggering may be employed as a protective element for a standard consuming device according to standard EN 61131 for memory-programmable control devices.

(26) According to another example, output capacitors can provide the output current I.sub.OUT needed for interrupting the signal output path for only a short time, for, in particular, a power supply unit 100 with an output voltage U.sub.OUT of 24 V and an output current I.sub.OUT of 20 or 40 A. Here, the length of the time interval may depend on the value of the remaining resistances, such as the line resistance 301.

(27) According to still another example, due to the short pulse duration of a few milliseconds, such as the predetermined time interval, all of the components in an output path of the power supply unit 100 can be designed for the increased electrical load. This can be done based on operating safety and thermal capacity. Only a small additional heating is expected, as a result of the substantially longer pauses, such as the additional predetermined time interval between the pulses or the increasing 205 of the output current I.sub.OUT. If the power source of the power supply unit 100 is designed to provide the required electrical power or energy, with correspondingly low resistance, then the required power or energy can be distributed between a mains connection and an input electrolytic capacitor. This can be achieved if the power source is comprised of an alternating current connection for low voltage networks having an alternating voltage of 120 or 230 VAC.

(28) According to yet another example, the power source of the power supply unit 100 may be substantially loaded, as a result of the high power uptake of the power supply unit 100. The supply voltage U.sub.IN or a supplying voltage may fall, in the event of a limited power source or as a result of an inner resistance of the source and a resistance of a supply line. Particularly in the case of a DC/DC converter, this voltage drop can result in a minimum input voltage for the DC/DC converter being undercut, and shutting off of a power supply unit 100 designed as a DC/DC converter, or shutting off of a consuming device connected in parallel with the power supply unit 100. In order to limit this voltage drop, if the supply voltage U.sub.IN decreases below a threshold value, the electric power delivered by the power supply unit 100 can be limited such that no additional voltage decrease occurs. This can result in reversal of the increasing 205 of the output current I.sub.OUT or of the increasing of the short-time current. Further, the threshold value may be above a shutoff threshold value of the power supply unit 100.

(29) In another example, the increasing 205 of the output current I.sub.OUT or the increasing of the short-time current can be deactivated by a user. This can be enabled only with difficulty in the event that output capacitors are connected.

(30) According to another example, a high output current I.sub.OUT may result when an output capacitor is used and a low-resistance short circuit occurs in the consuming device. When a high-resistance short circuit occurs, only a small amount of electrical energy will be available for interrupting the signal output path 105, due to the exponential discharging of the output capacitor. To increase the electrical energy, an output capacitor with a correspondingly higher capacitance may be employed. The repeatability of the increasing 205 of the output current I.sub.OUT or the pulse is difficult to achieve if an output capacitor is used, because the output capacitor can only be charged in a difficult way without remedying the malfunction 305 or without opening the short circuit.

(31) All of the features described and illustrated in connection with particular embodiments of the principles described herein may be provided in various combinations within the scope of this disclosure in order to simultaneously realize their advantageous effects.

(32) The scope of protection of the invention is provided by the claims, and is not limited to the features elucidated in the description or illustrated in the drawings.

LIST OF REFERENCE NUMERALS

(33) 100 Power supply unit 101 Output 103 Protective element 105 Signal output path 200 Method 201 Measuring 203 Reducing 205 Increasing 300 Arrangement 301 Line resistance 303 Consuming device 305 Malfunction 401 First plot of output voltage 403 Second plot of output voltage 405 Third plot of output voltage 407 First plot of output current 409 Second plot of output current U.sub.IN Supply voltage U.sub.OUT Output voltage U.sub.NOM Nominal output voltage I.sub.OUT Output current I.sub.1 Maximum output current I.sub.2 Nominal output current t Time t.sub.1 First time point t.sub.2 Second time point