Power cord photocoupler leakage current detection interrupter (LCDI) and electrical appliance using same
A power cord photocoupler leakage current detection interrupter (LCDI) includes: a switch unit provided between an input terminal and an output terminal, and configured to control the input terminal and the output terminal to turn on or off; a leakage current detection line wrapped with a power cord connected between the switch unit and the output terminal, and configured to detect whether the power cord has a leakage current; and a leakage current interruption unit connected to the switch unit and the leakage current detection line, and configured to detect a leakage current signal of the leakage current detection line, and send a corresponding control signal to the switch unit according to the leakage current signal.
1 . A power cord photocoupler leakage current detection interrupter (LCDI), comprising:
a switch unit provided between an input terminal and an output terminal, and configured to control the input terminal and the output terminal to turn on or off;
a leakage current detection line wrapped with a power cord, and configured to detect whether the power cord has a leakage current, wherein the power cord is connected between the switch unit and the output terminal;
a leakage current interruption unit connected to the switch unit and the leakage current detection line, and configured to detect a leakage current signal of the leakage current detection line, and send a corresponding control signal to the switch unit according to the leakage current signal;
a test unit connected between the input terminal and the output terminal and connected to the leakage current detection line, the test unit including a test switch disposed in a plug portion, an additional signal line routed within the power cord and disposed beneath a metal outer layer of the power cord, and a discrete resistor disposed within the power cord beneath the metal outer layer; wherein the leakage current detection line is connected between the test switch and the discrete resistor; and wherein closing the test switch injects a current into the leakage current detection line through a test loop that includes the additional signal line and the discrete resistor within the power cord; and
the plug portion and the power cord, wherein the power cord is externally connected to the plug portion; the plug portion is configured to mount the switch unit, the leakage current interruption unit and the test unit; and the power cord comprises an insulated protective layer covering the metal outer layer, a live line, a neutral line, a ground line, the leakage current detection line, the additional signal line and the discrete resistor, wherein the metal outer layer covers the live line, the neutral line, the ground line, the leakage current detection line, the additional signal line and the discrete resistor.
2 . The power cord photocoupler LCDI according to claim 1 , wherein the leakage current interruption unit comprises a photocoupler leakage current detection module and a switch drive module;
the photocoupler leakage current detection module comprises a first path connected to the leakage current detection line, and a second path connected to the switch drive module, and is configured to generate and send the control signal to the switch drive module when detecting the leakage current signal of the leakage current detection line; and
a control terminal of the switch drive module is electrically connected to the switch unit, and configured to generate the corresponding control signal according to the leakage current signal, wherein the switch unit is controlled to turn off.
3 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 2 .
4 . The power cord photocoupler LCDI according to claim 1 , wherein the discrete resistor is a first resistor, and the photocoupler leakage current detection module comprises a second resistor, a third resistor, a fourth resistor, a first rectifier, a fifth resistor and a photocoupler;
a first path of an input-terminal line L is connected to an input-terminal line N through the second resistor and the third resistor to form a voltage regulating loop;
a first input terminal of the first rectifier is connected to the voltage regulating loop; and a second path of the input-terminal line L is connected to a second input terminal of the first rectifier through the fourth resistor; and
an output terminal of the first rectifier comprises a path connected to the photocoupler through the fifth resistor.
5 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 4 .
6 . The power cord photocoupler LCDI according to claim 4 , wherein a switch drive module comprises a solenoid, a second rectifier, a sixth resistor, the photocoupler, a seventh resistor, an eighth resistor and a silicon controlled rectifier;
a path of the input-terminal line L is grounded through the solenoid, the second rectifier, the sixth resistor and the eighth resistor to form a static loop; and the static loop is a current loop when the photocoupler is not triggered;
the photocoupler comprises a first path connected between the sixth resistor and the eighth resistor in the static loop, and a second path connected to a gate of the silicon controlled rectifier through the seventh resistor to form a trigger loop; and the trigger loop is a current loop when the photocoupler is triggered;
the silicon controlled rectifier comprises an anode connected to a front terminal of the sixth resistor in the static loop, the gate connected to the trigger loop, and a cathode grounded; and
the trigger loop is configured to trigger the silicon controlled rectifier to turn on.
7 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 6 .
8 . The power cord photocoupler LCDI according to claim 1 , wherein
a path of an input-terminal line L is connected to an input-terminal line N through the test switch, the additional signal line and the discrete resistor to form the test loop.
9 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 8 .
10 . The power cord photocoupler LCDI according to claim 8 , wherein the plug portion is further provided with a test switch button and a reset switch button.
11 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 10 .
12 . The power cord photocoupler LCDI according to claim 10 , wherein the plug portion is further provided with a startup indication lamp; and the startup indication lamp is connected to a power loop.
13 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 12 .
14 . An electrical appliance using a power cord photocoupler leakage current detection interrupter (LCDI), comprising the power cord photocoupler LCDI according to claim 1 .