TWI493208B - Alternate current detector - Google Patents

Description

AC power sensing device

The present invention relates to an alternating current power source, and more particularly to a sensing device for an alternating current power source.

Alternating Current (AC) is a current that varies periodically in both size and direction, with an average running value of zero in one cycle. Compared with DC power whose direction does not change with time, AC power transmission is more efficient. Therefore, the commercial and civil power supply in various countries is based on AC.

Since most of the electrical equipment is powered by AC power, if the AC power supply cannot be properly supplied, the electrical equipment cannot operate normally, which is likely to cause significant loss in the industrial production process. Therefore, detecting whether the AC power supply is normally powered is an important issue to be solved.

Figure 8 is a block diagram of a voltage detecting device 800 provided by the Patent Office No. M450732 of the Republic of China. The voltage detecting device 800 receives a waveform signal of an external AC power source, and compares the amplitude value of the waveform signal of the external AC power source with the amplitude value of the waveform signal of a standby AC power source. If the external AC power supply and the standby AC power supply are at the same time amplitude value. If the amplitude value of the external AC power waveform is smaller than the amplitude of the standby AC power waveform, it means that the voltage of the external AC power source is lower than the voltage rating of the standby AC power source. At this time, a control unit immediately switches a state of the device from the state of being connected to the external AC power source to a state of being connected to the standby AC power source, thereby preventing the voltage of the external AC power source from causing the machine to be down and shut down. The situation to maintain the normal operation of the machine.

However, most of the current AC power detection devices must be coupled to Stream power itself. As in the prior art of FIG. 8, the voltage detecting device 800 must be coupled to an external AC power source to detect and compare whether the voltage of the external AC power is reduced. If the AC power detecting device is coupled to the AC power source, the load of the AC power source is increased, which causes additional power consumption.

In view of the above problems, the present invention provides an AC power sensing device. In one embodiment, the AC power sensing device includes a housing, a solenoid, a rectifying and filtering circuit, and an amplifying driving circuit. The housing includes a perforation in the center thereof that receives a wire through which an AC power source is loaded. The solenoid is located inside the casing and surrounds the perforation, and senses a magnetic field generated by the AC power source on the wire to generate a first voltage. The rectifying and filtering circuit is located inside the casing, and rectifies and filters the first voltage to generate a second voltage. The amplifying driving circuit is located inside the casing, and the second voltage is amplified to generate an output current between a first output end and a second output end.

The invention provides an AC power sensing device. In one embodiment, the AC power sensing device includes a magnetic field sensing circuit, a rectifying and filtering circuit, and an amplifying driving circuit. The magnetic field sensing circuit senses a magnetic field of a specific region and generates a first voltage at a first node according to the intensity of the magnetic field, wherein a wire carrying an alternating current power source generates the magnetic field in the specific region. The rectifying and filtering circuit is coupled between the first node and a second node, and rectifies and filters the first voltage to generate a second voltage at the second node. The amplifying driving circuit is coupled to the second node, and the second voltage is amplified to generate an output current between a first output end and a second output end.

The AC power sensing device of the present invention directly senses the magnetic field generated by the alternating current, and thus is non-invasive, so that the sensing device can be conveniently installed on various existing devices without disassembling or destroying the existing device. In addition, the AC power sensing device of the present invention utilizes the power generated by the magnetic field to illuminate the indicator light without the need for an external power source. In addition, the AC power sensing device of the present invention converts the sensed AC signal into a digitalized ON/OFF electronic message. No. Undisturbed and can be detected over long distances. Finally, the plurality of AC power sensing devices of the present invention can be connected in series to each other to save input contacts of the programmable logic circuit.

(Figure 1)

100‧‧‧AC power sensing device

120‧‧‧ indicator light

110‧‧‧Perforation

130‧‧‧Feet set

130a, 130b, 130c, 130d‧‧‧ pins

(Fig. 3)

300‧‧‧AC power sensing device

350‧‧‧ wire

330a, 330b‧‧‧ pins

(Figure 5)

500‧‧‧AC power sensing device

560‧‧‧Magnetic field sensing circuit

561‧‧‧ Solenoid

570‧‧‧ indicator light

571‧‧‧LED indicator

572‧‧‧resistance

580‧‧‧Rectifier filter circuit

581‧‧‧ diode

582‧‧‧ Capacitance

590‧‧‧Amplification drive circuit

591, 592‧‧‧Optoelectronics

593‧‧‧resistance

(Fig. 6A, Fig. 6B, Fig. 7)

600, 650, 710, 720, ..., 7n0‧‧‧ AC power sensing device

640, 690, 700‧‧‧ programmable logic circuits

630a, 630b, 630c, 630d, 680a, 680b, 680c, 680d, 710a, 710b, 710c, 710d, 720a, 720b, 720c, 720d, 7n0a, 7n0b, 7n0c, 7n0d‧‧‧ pins

1 is a front view of an AC power sensing device according to the present invention; FIG. 2A is a schematic perspective view of an AC power sensing device according to the present invention; FIG. 2B is a cross-sectional AC through a center of an AC power sensing device. Schematic diagram of the magnetic field generated by the power source; Figure 3 is a schematic diagram of the AC power sensing device and the wire with alternating current; Figure 4 is the corresponding relationship between the output voltage of the AC power sensing device and the rms current of the alternating current FIG. 5 is a block diagram of an AC power sensing device according to the present invention; FIG. 6A is a schematic diagram of an embodiment of an AC power sensing device and a programmable logic circuit according to the present invention; FIG. FIG. 7 is a schematic diagram showing another embodiment of connecting an AC power sensing device and a programmable logic circuit according to the present invention; FIG. 7 is a diagram showing a connection between a plurality of AC power sensing devices and a programmable logic circuit according to the present invention; A schematic diagram of an example; FIG. 8 is a block diagram of a voltage detecting device provided by the Patent No. M450732 of the Republic of China.

The invention will now be further described with reference to the drawings and specific embodiments of the invention.

1 is a front elevational view of an AC power sensing device 100 in accordance with the present invention. The center of the front side of the AC power sensing device 100 has a through hole 110 through which a through hole 110 can accommodate a wire through which an AC power source is loaded. In addition, AC The front side of the source sensing device 100 also has an indicator light 120. The AC power sensing device 100 indicates by the indicator light 120 whether the amplitude of the AC power source loaded on the wire reaches a normal level. If the amplitude of the AC power source reaches the normal level, the indicator light 120 is illuminated; otherwise, if the amplitude of the unpowered AC power source or the AC power source on the wire does not reach the normal level, the indicator light 120 is extinguished. Therefore, the user can use the blinking state of the indicator light 120 to know whether the amplitude of the AC power source loaded on the wire reaches a normal level.

In addition, the front side of the AC power sensing device 100 also has a pin set 130. In one embodiment, the pin set 130 includes four pins 130a, 130b, 130c, 130d. The pins 130a and 130b are the two output ends of the AC power sensing device 100, that is, the AC power sensing device 100 generates an output current between the pins 130a and 130b. When the AC power source of the wire load has a normal level, the output current generated by the AC power sensing device 100 between the pins 130a and 130b is equal to a first level. When the unpowered AC power or the wire load AC power on the wire is lower than the normal level, the output current generated by the AC power sensing device 100 between the pins 130a and 130b is equal to a second level. Therefore, the user can use the magnitude of the output current generated by the AC power sensing device 100 to know whether the amplitude of the AC power source loaded on the wire reaches a normal level.

In an embodiment, the pin set 130 further includes pins 130c and 130d. The pin 130c is coupled to the 130d for use when the AC power sensing device 100 is connected in series with other AC power sensing devices. The manner in which the AC power sensing device 100 is connected in series with a plurality of other AC power sensing devices will be further described in FIG.

2A is a perspective view of an AC power sensing device in accordance with the present invention. A wire passes through the perforation in the center of the AC power sensing device. The wire is not coupled to the AC power sensing device, so the AC power sensing device does not become a load on the AC power source of the wire and does not cause additional power loss. The electric current Ip is on the wire. When the alternating current Ip on the wire changes amplitude with time, a magnetic field is induced around the wire, and the strength of the magnetic field changes with the amplitude of the alternating current Ip, as shown in Fig. 2B. Therefore, the AC power sensing device can determine the extinguishing state of the indicator light and the level of the output current by sensing the magnetic field around the central perforation.

3 is a schematic diagram of an AC power sensing device 300 and a lead 350 with alternating current. The center of the AC power sensing device 300 has a through hole 310. The wire 350 carries an alternating current Ip and passes through the perforations 310. At the same time, the AC power sensing device 300 has outputs 330a and 330b. The AC power sensing device 300 senses a magnetic field generated by the alternating current Ip around the perforation 310 to generate an output current between the output terminals 330a and 330b. In one embodiment, the load resistance at the output is 2KΩ, the current flowing through the output terminals 330a and 330b is Ic, and the level of the output current Ic is [24V-0.8V]/2KΩ.

Fig. 4 is a view showing the correspondence relationship between the output voltage Vce of the AC power supply sensing device and the rms current Ip of the alternating current. The output voltage Vce of the AC power sensing device has two levels, the first level is 0.8V, and the second level is 24V. When the rms current Ip of the alternating current rises from 0A to 1A, the output voltage Vce of the alternating current power sensing device drops from the second level 24V to the first level 0.8V in the period TPHL. When the rms current Ip of the alternating current drops from 1A to 0A, the output voltage Vce of the alternating current power sensing device rises from the first level 0.8V in the period TPLH to the 75% level of the second level 24V. Therefore, the user can judge whether the AC power source Ip is at a normal level by the level of the output voltage Vce.

Figure 5 is a block diagram of an AC power sensing device 500 in accordance with the present invention. In one embodiment, the AC power sensing device 500 includes a magnetic field sensing circuit 560, an indicator light 570, a rectifying and filtering circuit 580, and an amplifying driving circuit 590. The magnetic field sensing circuit 560 senses a magnetic field in a surrounding area of the central perforation of the outer casing of the alternating current power sensing device 500 and generates a first voltage at the first node 551 according to the intensity of the magnetic field. In one embodiment, the magnetic field sensing circuit 560 includes a solenoid 561 for sensing a magnetic field generated by a wire carrying one of the alternating current sources in a region surrounding the central perforation. The indicator light 570 is coupled between the first node 551 and the ground potential, and emits light according to the intensity of the first voltage. In one embodiment, the indicator light 570 includes a resistor 572 and an LED indicator 571.

The rectifying and filtering circuit 580 is coupled between the first node 551 and the second node 552 to rectify and filter the first voltage to generate a second voltage at the second node 552. In one embodiment, the rectifying and filtering circuit 580 includes a diode 581 and a capacitor 582. The diode 581 is coupled between the first node 551 and the second node 552 to rectify current flowing between the first node 551 and the second node 552. The capacitor 582 is coupled between the second node 552 and the ground potential. The amplification driving circuit 590 is coupled to the second node 552 to amplify the second voltage to generate an output current between the first output terminal 530a and the second output terminal 530b. In one embodiment, the amplification driver circuit 590 includes two transistors 591 and 592 and a resistor 593. The resistor 593 is coupled between the base of the transistor 591 and the second node 552. The transistor 591 has a collector coupled to the first output 530a. The transistor 592 has a base coupled to the emitter of the transistor 591, a collector coupled to the first output 530a, and an emitter coupled to the second output 530b.

FIG. 6A is a schematic diagram of an embodiment of the AC power sensing device 600 and the programmable logic circuit 640 in accordance with the present invention. The first output terminal 630a of the AC power sensing device 600 is coupled to the NPN I/P terminal of the programmable logic circuit 640, and the second output terminal 630b of the AC power sensing device 600 is coupled to the programmable logic circuit. 0V endpoint of 640. FIG. 6B is a schematic diagram of another embodiment of the AC power sensing device 650 and the programmable logic circuit 690 in accordance with the present invention. The first output 680a of the AC power sensing device 650 is coupled to the 24V end of the programmable logic circuit 690, and the second output 680b of the AC power sensing device 650 is coupled to the PNP of the programmable logic circuit 690. I/P endpoint.

Figure 7 is a schematic illustration of one embodiment of a plurality of AC power sensing devices 710, 720, ..., 7n0 coupled to programmable logic circuit 700 in accordance with the present invention. When a plurality of AC power sensing devices are connected in series, the AC power sensing devices located in the middle section are coupled in the same manner except for the AC power sensing devices at the beginning and the end. Take the AC power sensing device 720 as an example. The second pin 720b of the AC power sensing device 720 is coupled to the first pin 710a of the AC power sensing device 710 in front, and the fourth pin 720d of the AC power sensing device 720 is coupled to the AC power sense in the front. The third pin 710c of the measuring device 710. The first pin 720a of the AC power sensing device 720 is coupled to the second pin 730b of the rear AC power sensing device 730, and the third pin 720c of the AC power sensing device 720 is coupled to the rear AC power sense. The fourth pin 730d of the measuring device 730.

In addition, the first pin 7n0a of the most end AC power sensing device 7n0 is coupled to the third pin 7(n-1)0c of the front AC power sensing device 7(n-1)0, and the sense of AC power The second pin 7n0b of the measuring device 7n0 is coupled to the first pin 7(n-1)0a of the front AC power sensing device 7(n-1)0. The first pin 710a of the front-end AC power sensing device 710 is coupled to the com end of the front programmable logic circuit 700, and the fourth pin 710d of the AC power sensing device 710 is coupled to the programmable logic. The NPN I/P endpoint of circuit 700. In this way, the output voltages of the plurality of AC power sensing devices 710, 720, . . . , 7n0 are summed across the second pin 710b and the fourth pin 710d of the first AC power sensing device 710, so The programmable logic circuit 700 only needs to be coupled to the two ends of the first AC power sensing device 710, and can detect multiple AC power sources passing through the plurality of AC power sensing devices 710, 720, . . . , 7n0. Whether any of them has an abnormal power supply or a power failure.

The AC power sensing device of the present invention directly senses the magnetic force generated by the alternating current The field is therefore non-invasive, so it is convenient to install this sensing device on any existing equipment without disassembling or destroying existing equipment. In addition, the AC power sensing device of the present invention utilizes the power generated by the magnetic field to illuminate the indicator light without the need for an external power source. In addition, the AC power sensing device of the present invention converts the sensed AC signal into a digitalized ON/OFF electronic signal that is undisturbed and can be detected over long distances. Finally, the plurality of AC power sensing devices of the present invention can be connected in series to each other to save input contacts of the programmable logic circuit.

500‧‧‧AC power sensing device

560‧‧‧Magnetic field sensing circuit

561‧‧‧ Solenoid

570‧‧‧ indicator light

571‧‧‧LED indicator

572‧‧‧resistance

580‧‧‧Rectifier filter circuit

581‧‧‧ diode

582‧‧‧ Capacitance

590‧‧‧Amplification drive circuit

591, 592‧‧‧Optoelectronics

593‧‧‧resistance

Claims (8)

An AC power sensing device has a first output end and a second output end, comprising: a solenoid, sensing a magnetic field of a specific area and generating a first node according to the strength of the magnetic field a first voltage, wherein a wire carrying an AC power source generates the magnetic field in the specific region; a rectifying and filtering circuit coupled between the first node and a second node, rectifying and filtering the first voltage Generating a second voltage at the second node; and an amplification driving circuit coupled to the second node, amplifying the second voltage to generate an output current between the first output end and the second output end; The rectifying and filtering circuit includes: a diode coupled between the first node and the second node, and a current rectification flowing between the first node and the second node; and a capacitor coupled Connected between the second node and a ground potential. The AC power sensing device of claim 1, further comprising an indicator light coupled between the first node and a ground potential to emit light according to the intensity of the first voltage. The AC power sensing device of claim 1, wherein the amplifying driving circuit comprises: a first transistor having a collector coupled to the first output; a resistor coupled to the first a base of the crystal and the second node; and a second transistor having a base coupled to the emitter of the first transistor, a collector coupled to the first output, and a shot The pole is coupled to the second output. The AC power sensing device of claim 1, wherein the AC power sensing device inputs the output current to a programmable logic circuit via the first output terminal and the second output terminal. PLC). For example, the AC power sensing device of claim 1 of the patent scope, wherein the AC power source One of the sensing devices has a first pin, a second pin, a third pin and a fourth pin, and the first pin is coupled to the second pin, wherein the AC When the power sensing device is connected in series with a front AC power sensing device and a rear AC power sensing device, the first output end of the AC power sensing device is coupled to one of the rear AC power sensing devices. The second output end of the AC power sensing device is coupled to the first output end of the front AC power sensing device, and the first pin of the AC power sensing device is coupled to the rear a second pin of the AC power sensing device, wherein the second pin of the AC power sensing device is coupled to the first pin of the rear AC power sensing device, and the fourth pin is coupled to The third pin of the front AC power sensing device is coupled to the fourth pin of the rear AC power sensing device. An AC power sensing device includes: a housing including a through hole, the through hole accommodating a wire having an AC power source passing therethrough, and having a first output end and a second output end; a solenoid Located inside the casing and surrounding the perforation, sensing a magnetic field generated by the AC power source on the electric wire to generate a first voltage; a rectifying and filtering circuit, rectifying and filtering the first voltage to generate a a second voltage; and an amplification driving circuit, the second voltage is amplified to generate an output current between the first output end and the second output end; wherein the AC power sensing device passes the first output end and the The second output inputs the output current to a programmable logic circuit (PLC). The AC power sensing device of claim 6 further includes an indicator light coupled to the solenoid for emitting light according to the intensity of the first voltage. The AC power sensing device of claim 6 , wherein the outer casing further has a first pin, a second pin, a third pin and a fourth pin, and the first pin is coupled To the second pin, wherein the AC power sensing device is connected in series with a front AC power sensing device and a rear AC power sensing device The first output end of the current power sensing device is coupled to the second output end of the rear AC power sensing device, and the second output end of the AC power sensing device is coupled to the front AC power sensing device a first output end, the first pin of the AC power sensing device is coupled to a second pin of the rear AC power sensing device, and the second pin of the AC power sensing device is coupled Connected to the first pin of the AC power sensing device, the fourth pin is coupled to the third pin of the front AC power sensing device, and the third pin is coupled to the rear AC power sensing device The fourth pin of the device.