TWI571647B - Alternating current? input voltage detecting device - Google Patents

Description

AC input voltage sensing device

The present invention relates to a power supply sensing device, and more particularly to an AC voltage sensing device that senses whether a live line or a ground line voltage of an AC power source is abnormal.

In general, electronic products require proper power to function properly. Therefore, in order to avoid the problem that the electronic product cannot operate or even cause damage when the AC power supply is abnormally supplied with power, a voltage sensing device may be disposed between the AC power source and the electronic product to sense whether the AC power source is abnormal.

The conventional AC voltage sensing device can correctly determine the loss of the AC power source when the ground voltage and the line voltage of the AC power source are abnormal at the same time, and output an abnormal warning signal to achieve the effect of protecting the electronic product. However, if only the ground line voltage or the live line voltage is abnormal, the ground line voltage of the AC power source or the loss of the line voltage power supply cannot be correctly judged, so it is impossible to achieve protection when only the ground line voltage or the line voltage is abnormal. The effect of electronic products.

The invention provides an AC voltage sensing device for individually sensing whether the power supply of the live line and the ground line of the AC power source is abnormal.

According to the present invention, an AC voltage sensing device is electrically connected to an AC power source, and the AC voltage sensing device includes a first input terminal, a second input terminal, a determining unit, a first voltage sensing unit, and a second voltage sensing unit. The first input end is electrically connected to the ground of the AC power source, and the second input end is electrically connected to the live line of the AC power source. The determining unit includes a first power switch, a second power switch, and an output end. The first power switch and the second power switch are connected in series, and the output end is coupled to the second power switch. The first voltage sensing unit is electrically connected to the first input end and the first power switch, and the second voltage sensing unit is electrically connected to the second input end and the second power switch. The judging unit outputs a normal operation signal from the output terminal when the live line and the ground line of the AC power source are normally powered.

The AC voltage sensing device of the present invention detects the ground voltage and the hot line voltage of the AC power source, and supplies power to the ground line voltage and the line voltage normally, and outputs a normal power supply signal; the ground line voltage or the line voltage of the AC power source is abnormal. The power supply, or the ground line voltage and the live line voltage all output abnormal power supply signals when abnormal power supply occurs. In this way, it can be accurately judged whether the AC power supply is abnormal, and the normal power supply signal is still output when the ground line voltage or the live line voltage is abnormally supplied with power.

10‧‧‧judging unit

100‧‧‧First power switch

102‧‧‧second power switch

104, 108‧‧‧ Current limiting resistor

106‧‧‧Photocoupler

1060‧‧‧Lighting parts

1062‧‧‧Lighting parts

110, 112, 130, 132, 134, 136, 150, 152, 154, 156‧‧‧ resistors

12‧‧‧First voltage sensing unit

120‧‧‧First switch

122‧‧‧First current limiter

124‧‧‧First resistance network

126‧‧‧First capacitor

128‧‧‧First voltage regulator

14‧‧‧Second voltage sensing unit

140‧‧‧second switch

142‧‧‧Second current limiter

144‧‧‧second resistance network

146‧‧‧second capacitor

148‧‧‧second voltage regulator

L‧‧‧ second input

N‧‧‧ first input

OUT‧‧‧ output

VDC‧‧‧ DC voltage

Vs‧‧‧AC voltage

VSL‧‧‧Firewire voltage

VSN‧‧‧ ground voltage

1 is a circuit diagram of an AC input voltage sensing device of the present invention; and FIG. 2 is a waveform diagram of a ground voltage, a line voltage, and an output terminal of the AC input voltage sensing device of the present invention.

The input voltage sensing device of the present invention is configured to sense an input voltage of a live wire and a neutral wire of an alternating current power source Vs, and determine whether an abnormality occurs between an input voltage of a live wire and a ground wire, and may be in a fire line and Enter the normal power supply signal when the ground voltage is normal.

Please refer to FIG. 1, which is a circuit diagram of an AC input voltage sensing device of the present invention. The AC input voltage sensing device includes a first input terminal N, a second input terminal L, a determination unit 10, a first voltage sensing unit 12, and a second voltage sensing unit 14.

The first input terminal N is electrically connected to the ground of the AC power source Vs, and the second input terminal L is electrically connected to the line of the AC power source Vs.

The determining unit 10 includes an output terminal OUT, and a first power switch 100 and a second power switch 102 connected in series; as shown in FIG. 1, the first power switch 100 and the second power switch 102 are respectively implemented by metal oxide semiconductor transistors. It. The source of the first power switch 100 is grounded, the gate is electrically connected to the first voltage sensing unit 12, and the drain is electrically connected to the source of the second power switch 102. The gate of the second power switch 102 is electrically connected to the second voltage sensing unit 14, and the drain is electrically connected to the light emitting member 1060 of the photocoupler 106 through the current limiting resistor 104. The illuminating member 1060 can be realized, for example, by a light emitting diode. The cathode of the illuminating member 1060 is electrically connected to the current limiting resistor 104, and the anode is electrically connected to the direct current power source VDC. The light-receiving member 1062 of the photocoupler 106 can be realized, for example, by a photoelectric crystal. The collector of the light-receiving member 1062 is electrically connected to the DC power source VDC. The emitter is electrically connected to the output terminal OUT, and is also grounded through the current limiting resistor 108. .

The determining unit 10 further includes resistors 110 and 112. The resistor 110 is connected between the gate and the source of the first power switch 100. The resistor 112 is connected between the gate and the source of the second power switch 102. .

The first voltage sensing unit 12 is disposed between the first input terminal N and the first power switch 100 and is electrically connected to the first input terminal N and the first power switch 100. The first voltage sensing unit 12 includes a first switch 120 , a first current limiting device 122 , a first resistor network 124 , a first capacitor 126 , and a first voltage regulator 128 . One end of the first switch 120 is electrically connected to the first input end N, and the other end is electrically connected to the first current limiting member 122. One end of the first voltage stabilizing member 128 is connected to the gate of the first power switch 100, and the other end is grounded. The first capacitor 126 is electrically connected to the first voltage regulator 128. The first resistor network 124 is disposed between the first current limiting member 122 and the first voltage stabilizing member 128, and includes a plurality of resistors 130-136 connected in series, and one of the resistors 124 of the first resistor network 124 The 136 is electrically connected in parallel to the first voltage regulator 128. As shown in FIG. 1, the first voltage stabilizing member 128 can be implemented, for example, with a Zener diode, and the first voltage stabilizing member 128 has a breakdown voltage at least equal to the turn-on voltage of the first power switch 100.

The second voltage sensing unit 14 is disposed between the second input terminal L and the second power switch 102 and is electrically connected to the second input terminal N and the second power switch 102. The second voltage sensing unit 14 includes a second switch 140, a second current limiting member 142, a first resistor network 124, a second capacitor 146, and a second voltage regulator 148. One end of the second switch 140 is electrically connected to the second input end L, and the other end is electrically connected to the second current limiting member 142. One end of the second voltage stabilizing member 148 is connected to the gate of the second power switch 102, and the other end is grounded. The second capacitor 146 is electrically connected in parallel to the second voltage regulator 148. The second resistor network 144 is disposed between the second current limiting member 142 and the second voltage stabilizing member 148 and includes a plurality of resistors 150-156 connected in series, and one of the resistors 144 in the second resistor network 144 The 156 is electrically connected in parallel to the second voltage regulator 148. As shown in FIG. 1, the second voltage stabilizing member 148 can be implemented, for example, with a Zener diode, and the second voltage stabilizing member 148 has a breakdown voltage at least equal to the turn-on voltage of the second power switch 102.

When actually implemented, when the ground voltage VSN and the hot line voltage VSL of the AC power source Vs are normally powered, the first switch 120 is closed, so that the ground voltage VSN of the AC power source Vs enters the first voltage sensing from the first input terminal N. The unit 12, the second switch 140 is closed, so that the live line voltage VSL of the alternating current power source Vs enters the second voltage sensing unit 14 through the second input terminal L.

The voltage input from the ground (or live line) of the AC power source Vs is divided by the first resistor network 124 (or the second resistor network 144) after passing through the first current limiter 122 (or the second current limiter 142). A voltage across the resistor 136 (or resistor 156) is formed. If the voltage across the resistor 136 (or the resistor 156) is higher than the reverse voltage of the first voltage regulator 128 (or the second voltage regulator 148), the first power switch 100 (or the second power switch) The gate source voltage of 102) corresponds to the voltage across the first voltage regulator 128, and the first power switch 100 (or the second power switch 102) is turned on.

In short, when the ground voltage VSN of the AC power source Vs is normally powered, the first power switch 100 can be turned on, and when the line voltage VSL of the AC power source Vs is normally powered, the second power switch 102 can be turned on. On the other hand, when the ground voltage VSN of the AC power source Vs is abnormally supplied, the first power switch 100 is turned off, and when the line voltage VSL of the AC power source Vs is abnormally supplied, the second power switch 102 can be turned off.

When the ground voltage VSN and the live voltage VSL of the AC power supply Vs are normally powered, the first power switch 100 and the second power switch 102 are both turned on, so that the light-emitting member 1060 is turned on and generates light, and the light-receiving member 1062 senses the light-emitting member. The light emitted by the 1060, the output terminal OUT outputs a normal power supply signal at a high level, as shown in FIG.

When the ground voltage VSN of the AC power source Vs is abnormally supplied, the first power switch 100 is turned off, the second power switch 102 is turned on, and the light-emitting member 1060 cannot generate light, so the output terminal OUT Outputs an abnormal power supply signal at a low level. When the live line voltage VSL of the AC power source Vs is abnormally supplied, the first power switch 100 is turned on, the second power switch 102 is turned off, and the light emitting device 1060 cannot generate light, so the output terminal OUT outputs an abnormal power supply signal with a low level, as shown in FIG. 2 . Shown.

Similarly, when the ground voltage VSN and the live line voltage VSL of the AC power source Vs are abnormally supplied, the first power switch 100 and the second power switch 102 are both turned off, and the light emitting device 1060 cannot generate light, so the output OUT output is low. The abnormal power supply signal of the bit is as shown in FIG. 2; wherein, whether the ground voltage VSN and the hot line voltage VSL received by the AC voltage sensing device of the present invention are abnormally corresponding to the input signal of the output terminal are as shown in Table 1.

In summary, the AC voltage sensing device of the present invention detects the ground voltage VSN and the hot line voltage VSL of the AC power source Vs, and supplies power to the ground line voltage VSN and the line voltage VSL, and the output terminal OUT outputs a normal power supply signal. When the ground line voltage VSN or the line voltage VSL of the AC power supply Vs is abnormally supplied with power, or the ground line voltage VSN and the line voltage VSL are abnormally supplied with power, the output terminal OUT outputs an abnormal power supply signal. In this way, it can be accurately determined whether the AC power supply Vs power supply is abnormal, and the normal power supply signal is still output when the ground line voltage VSN or the live line voltage VSL is abnormally supplied with power.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and various modifications may be made without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims.

10‧‧‧judging unit

100‧‧‧First power switch

102‧‧‧second power switch

104, 108‧‧‧ Current limiting resistor

106‧‧‧Photocoupler

1060‧‧‧Lighting parts

1062‧‧‧Lighting parts

110, 112, 130, 132, 134, 136, 150, 152, 154, 156‧‧‧ resistors

12‧‧‧First voltage sensing unit

120‧‧‧First switch

122‧‧‧First current limiter

124‧‧‧First resistance network

126‧‧‧First capacitor

128‧‧‧First voltage regulator

14‧‧‧Second voltage sensing unit

140‧‧‧second switch

142‧‧‧Second current limiter

144‧‧‧second resistance network

146‧‧‧second capacitor

148‧‧‧second voltage regulator

L‧‧‧ second input

N‧‧‧ first input

OUT‧‧‧ output

VDC‧‧‧ DC voltage

Vs‧‧‧AC voltage

VSL‧‧‧Firewire voltage

VSN‧‧‧ ground voltage

Claims (8)

An AC voltage sensing device is electrically connected to an AC power source, the AC voltage sensing device includes: a first input end electrically connected to a ground line of the AC power source; and a second input end electrically connected to the AC line a first power switch, a second power switch, and an output end, the first power switch and the second power switch are connected in series, and the output end is coupled to the second power a first voltage sensing unit electrically connected to the first input terminal and the first power switch; and a second voltage sensing unit electrically connected to the second input terminal and the second power switch; wherein The determining unit outputs a normal power supply signal from the output terminal when the live line of the AC power source and the ground line are normally powered. The AC voltage sensing device of claim 1, wherein the determining unit generates abnormal power supply to the live line or the ground line of the AC power source, or when the hot line and the ground line simultaneously generate abnormal power supply, The output outputs an abnormal power supply signal. The AC voltage sensing device of claim 2, wherein the determining unit further comprises a photocoupler and a second current limiting resistor, the photocoupler comprising a light emitting member and a light collecting member, the light emitting member passing One of the current limiting resistors is electrically connected to the second power switch, and the light collecting member is optically coupled to the light emitting member and electrically connected to the output end and another current limiting resistor. The AC voltage sensing device of claim 3, wherein the first power switch, the second power switch, the illuminating member, and the light receiving member are both turned on when the ground line and the live line are powered normally. The output outputs the normal operation signal. The AC voltage sensing device of claim 4, wherein the first voltage sensing unit comprises a first current limiting component, a first resistor network, and a first voltage regulator, the first current limiting An element is electrically connected to the first resistor network, the first voltage regulator is electrically connected to the first resistor network and the first power switch, and the second voltage sensing unit comprises a second current limiting component, a first a second resistor network and a second voltage regulator, the second current limiting component is electrically connected to the second resistor network, and the second voltage regulator is electrically connected to the second resistor network and the second power switch. The AC voltage sensing device of claim 5, wherein the first voltage sensing unit further comprises a first switch disposed between the first input end and the first current limiting component and electrically connected to The first input terminal and the first current limiting component, the second voltage sensing unit further includes a second switch disposed between the second input terminal and the second current limiting component, and electrically connected to the first Two output ends and the second current limiting element. The AC voltage sensing device of claim 5, wherein the first voltage sensing unit further comprises a first capacitor, the first capacitor is connected in parallel with the first voltage regulator, the first The two voltage sensing unit further includes a second capacitor, and the second capacitor is connected in parallel with the second voltage regulator. The AC voltage sensing device of claim 5, wherein the first resistor network and the second resistor network respectively comprise a plurality of resistors connected in series, and one of the resistors in the first resistor network is The first voltage stabilizing members are connected in parallel, and one of the resistors in the second resistor network is connected in parallel with the second voltage stabilizing component.