Non-polarity circuits in DC power distribution systems

Abstract

To provide a non-polar circuit with restricted loss due to a voltage drop.SOLUTION: A non-polar circuit in a direct-current power distribution system comprises a first cable way 31 and a third cable way 33 having one end connected with a power source 1 and the other end connected with a load 2, a first LED 4 is provided on the first cable way 31 and the third cable way 33, a second LED 5 is provided in parallel to the first LED 4, a first FETNch 61 is provided in series at a position where the voltage is lower than the first LED 4 on the first cable way 13, a source of a second FETPch 71 is connected with the first cable way 31 at a position where the voltage is lower than the first LED 4, a drain of a second FETPch 71 is connected with the third cable way 33 at a position where the voltage is lower than the load 2, a fourth FETPch 91 is provided in series at a position where the voltage is lower than the load on the third cable way 33, a source of a third FETNch 81 is connected with the third cable way 33 at a position where the voltage is higher than the first LED 4 and a drain of the third FETNch 81 is connected with the first cable way 31 at a position where the voltage is higher than the load 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a non-polar circuit in which a circuit operates whether the power supply is connected in series or in reverse.

Background Art

[0002] Since a power supply for supplying power to a load such as an LED lighting device for DC power distribution has a polarity, if it is reversely connected, the load may be damaged.

[0003] Therefore, conventionally, in order to prevent damage to the load and protect the load when the polarity of the power supply is reversely connected, the voltage of the power supply is detected, and if it is appropriate, it is turned ON (= the circuit is conducted), or if it is inappropriate, it is turned OFF (= the circuit is interrupted). A configuration in which a voltage detection circuit using a comparator or the like is provided is disclosed.

[0004] In addition, a configuration in which a diode is provided in series with the circuit so that no current flows when the polarity of the power supply is reversely connected is disclosed.

[0005] For example, in Patent Document 1, as a conventional technique, a configuration in which a diode and an electric circuit to be protected are connected in series between a positive power supply terminal and a negative power supply terminal is disclosed. In this configuration, when the power supply is reversely connected and the potential of the negative power supply terminal is higher than the potential of the positive power supply terminal, the current is blocked by the diode.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0007] However, if a voltage detection circuit is included, it is inconvenient because a separate circuit needs to be configured for voltage detection.

[0008] Furthermore, in a configuration where a diode is placed in series with the circuit, a typical PN junction diode has a voltage drop V F This results in a voltage drop and power loss of approximately 0.6V. When the current flowing through the circuit is high or the voltage is high, a voltage drop and power loss of around 0.6V is not much of a problem. However, when the current flowing through the circuit is low or the voltage is low, even 0.6V represents a significant loss and becomes a problem.

[0009] Incidentally, as a measure to prevent damage to the load when the power supply is connected in reverse, one approach is to create a non-polarized circuit that will operate regardless of whether the power supply is connected in forward or reverse polarity. In achieving non-polarization, a known configuration involves incorporating a diode bridge into the circuit.

[0010] However, in the case of a configuration in which a diode bridge is provided in the circuit, the voltage drop V across the diode occurs. F (V F This will result in a loss equivalent to two units, and the heat treatment for this loss must be considered and addressed.

[0011] Therefore, the present invention aims to provide a non-polar circuit that suppresses losses due to voltage drop, thereby solving the above-mentioned problems. [Means for solving the problem]

[0012] The invention of claim 1 is, A non-polarized circuit that operates regardless of whether the power supply is connected in forward or reverse. A first circuit in which the positive terminal of the power supply is connected to one end and one end of the load is connected to the other end, The circuit comprises a third circuit to which the negative terminal of the power supply is connected at one end and the other end of the load is connected at the other end. A first semiconductor light-emitting element is provided in series on the first circuit such that its cathode faces in the direction of the lower voltage. On the third circuit, in the downward voltage direction anode The first semiconductor light-emitting element is arranged in series so that it faces the light source. A second semiconductor light-emitting element is provided in parallel with the first semiconductor light-emitting element, in a orientation opposite to that of the first semiconductor light-emitting element. A first field-effect transistor Nch is provided in series on the first circuit at a voltage lower than that of the first semiconductor light-emitting element, with its drain connected in the lower voltage direction and its source connected in the higher voltage direction. The source of the second field-effect transistor Pch is connected to the first circuit at a voltage lower than that of the first semiconductor light-emitting element. The drain of the second field-effect transistor Pch is connected to the third circuit at a position where the voltage is lower than that of the load. The gates of the first field-effect transistor Nch and the second field-effect transistor Pch are connected to the first circuit at a voltage higher than that of the first semiconductor light-emitting element. A fourth field-effect transistor Pch is provided in series on the third circuit at a position where the voltage is lower than that of the load, with its drain connected in the direction of higher voltage and its source connected in the direction of lower voltage. The source of the third field-effect transistor Nch is connected to the third circuit at a position where its voltage is higher than that of the first semiconductor light-emitting element. The drain of the third field-effect transistor Nch is connected to the first circuit at a position where the voltage is higher than that of the load. The gates of the third field-effect transistor Nch and the fourth field-effect transistor Pch are connected to the third circuit at a voltage lower than that of the first semiconductor light-emitting element, thus forming a non-polarized circuit.

[0013] Furthermore, the invention of claim 2 is, A non-polarized circuit that operates regardless of whether the power supply is connected in forward or reverse. A first circuit in which the positive terminal of the power supply is connected to one end and one end of the load is connected to the other end, A third circuit is provided, with the negative electrode of the power supply connected to one end and the other end of the load connected to the other end. On the first circuit, a first semiconductor light-emitting element is provided in series such that the cathode faces in the lower voltage direction. On the third circuit, anode the first semiconductor light-emitting element is provided in series such that it faces in the lower voltage direction. A second semiconductor light-emitting element is provided in parallel with the first semiconductor light-emitting element and in a direction opposite to that of the first semiconductor light-emitting element. At a position where the voltage is lower than that of the first semiconductor light-emitting element on the first circuit, a first N-channel field-effect transistor is provided in series with its drain connected in the lower voltage direction and its source connected in the higher voltage direction. The gate of the first N-channel field-effect transistor is connected to the first circuit at a position where the voltage is higher than that of the first semiconductor light-emitting element. The drain of a second N-channel field-effect transistor is connected to the first circuit at a position where the voltage is lower than that of the first semiconductor light-emitting element. The source of the second N-channel field-effect transistor is connected to the third circuit through the second circuit at a position where the voltage is lower than that of the load. The gate of the second N-channel field-effect transistor is connected to the second circuit through the fifth circuit. The fifth circuit is connected to the third circuit at a position where the voltage is higher than that of the first semiconductor light-emitting element and lower than that of the drain of a third N-channel field-effect transistor. On the fifth circuit, a constant-voltage semiconductor element is provided in series such that the anode faces in the direction of the second circuit. At a position where the voltage is lower than that of the load on the third circuit, a third N-channel field-effect transistor is provided in series with its source connected in the higher voltage direction and its drain connected in the lower voltage direction. The gate of the third N-channel field-effect transistor is connected to the third circuit through the fourth circuit. The fourth circuit is connected to the first circuit at a position where the voltage is lower than that of the first semiconductor light-emitting element and higher than that of the source of the first N-channel field-effect transistor. On the fourth circuit, a constant-voltage semiconductor element is provided in series such that the anode faces in the direction of the third circuit. The source of the fourth N-channel field-effect transistor is connected to the third circuit at a position where the voltage is higher than that of the first semiconductor light-emitting element. The drain of the fourth N-channel field-effect transistor is connected to the first circuit at a position where the voltage is higher than that of the load. The gate of the fourth N-channel field-effect transistor is connected to the third circuit at a position where the voltage is lower than that of the first semiconductor light-emitting element, forming a non-polarity circuit.

Advantages of the Invention

[0014] By applying and using the non-polarity circuit according to the present invention, there is no need to pay attention to the polarity when connecting the power supply, which is convenient.

[0015] Instead of providing a diode bridge in the circuit, by providing a field-effect transistor (FET) in the circuit, voltage drop and power loss can be minimized.

[0016] To turn on a field-effect transistor, the potential of the gate must be higher than that of the source. In the non-polarity circuit according to the present invention, since the forward voltage (V F ) and voltage drop of the semiconductor light-emitting element are utilized to lower the potential of the source, when the load connected to the non-polarity circuit is the substrate of the semiconductor light-emitting element, the efficiency is good.

Brief Description of the Drawings

[0017] [Figure 1] It is a configuration diagram of the non-polarity circuit of Embodiment Example 1 of the present invention. [Figure 2] It is a conceptual configuration diagram of the field-effect transistor according to the non-polarity circuit of Embodiment Example 1 of the present invention. [Figure 3] It is an explanatory diagram showing the operation of the field-effect transistor according to the non-polarity circuit of Embodiment Example 1 of the present invention. [Figure 4]This is an explanatory diagram showing the operation of a field-effect transistor in a non-polarized circuit according to Embodiment Example 1 of the present invention. [Figure 5] This is an explanatory diagram showing the operation of a non-polarized circuit according to Embodiment Example 1 of the present invention. [Figure 6] This is an explanatory diagram showing the operation of a non-polarized circuit according to Embodiment Example 1 of the present invention. [Figure 7] This is a diagram showing the configuration of a non-polarized circuit according to Embodiment Example 2 of the present invention. [Figure 8] This is an explanatory diagram showing the operation of a non-polarized circuit according to Embodiment Example 2 of the present invention. [Figure 9] This is an explanatory diagram showing the operation of a non-polarized circuit according to Embodiment Example 2 of the present invention. [Modes for carrying out the invention]

[0018] (Example of Embodiment 1) First, the configuration of the non-polarized circuit A of Embodiment Example 1 of the present invention will be described with reference to Figure 1. The non-polarized circuit A is a circuit that operates regardless of whether the polarity of the power supply is connected in forward or reverse.

[0019] <Configuration of non-polarized circuit A> As shown in Figure 1, the non-polarized circuit A includes a first circuit 31 to which the positive terminal of a DC power supply 1 is connected at one end and one end of a load 2 is connected at the other end, and a third circuit 33 to which the negative terminal of the power supply 1 is connected at one end and the other end of a load 2 is connected at the other end. Note that Figure 1 shows the case where the polarity of the power supply 1 is connected in the forward direction, and the arrangement of each element will be explained based on that.

[0020] On the first circuit 31, a first semiconductor light-emitting element (LED) 4 is arranged in series with its cathode (indicated as "K" in Figure 1) facing downwards in voltage direction. And on the third circuit 33, anodeThe first semiconductor light-emitting element 4 is arranged in series so that it faces (indicated as "A" in Figure 1). In addition, the second semiconductor light-emitting element (LED) 5 is arranged in parallel with the first semiconductor light-emitting element 4 on the first circuit 31 and the third circuit 33, respectively, so as to face the opposite direction to the first semiconductor light-emitting element 4.

[0021] A first field-effect transistor Nch (N-channel) 61 is connected in series to the first circuit 31 at a voltage lower than that of the first semiconductor light-emitting element 4. The drain (indicated as "D" in Figure 1) is connected in the direction of the lower voltage, and the source (indicated as "S" in Figure 1) is connected in the direction of the higher voltage.

[0022] The source of the second field-effect transistor Pch (P-channel) 71 is connected to the first circuit 31 at a voltage lower than that of the first semiconductor light-emitting element 4, and the drain of the second field-effect transistor Pch 71 is connected to the third circuit 33 at a voltage lower than that of the load 2.

[0023] The gates of the first field-effect transistor Nch61 and the second field-effect transistor Pch71 (indicated as "G" in Figure 1) are connected to the first circuit 31 at a voltage higher than that of the first semiconductor light-emitting element 4.

[0024] A fourth field-effect transistor Pch91 is installed in series on the third circuit 33 at a voltage lower than that of the load 2, with its drain connected in the direction of higher voltage and its source connected in the direction of lower voltage.

[0025] The source of the third field-effect transistor Nch81 is connected to the third circuit 33 at a voltage higher than that of the first semiconductor light-emitting element 4, and the drain of the third field-effect transistor Nch81 is connected to the first circuit 31 at a voltage higher than that of the load 2.

[0026] The gates of the third field-effect transistor Nch81 and the fourth field-effect transistor Pch91 are connected to the third circuit 33 at a voltage lower than that of the first semiconductor light-emitting element 4.

[0027] <Current flow in a field-effect transistor> Next, the current flow in the first to fourth field-effect transistors will be explained. In this embodiment, Example 1, the first field-effect transistor Nch61 and the third field-effect transistor Nch81 are n-channel MOS-FETs (insulated-gate field-effect transistors). The second field-effect transistor Pch71 and the third field-effect transistor Pch91 are p-channel MOS-FETs. Below, the current flow in the field-effect transistors will be explained using the first field-effect transistor Nch61, which is an n-channel MOS-FET, as an example. Note that the third field-effect transistor Nch81 has the same configuration as the first field-effect transistor Nch61, so its explanation will be omitted.

[0028] As shown in Figure 2, generally, the first field-effect transistor Nch61 is constructed by joining a p-type semiconductor 611 and an n-type semiconductor 612. More specifically, it is constructed by joining "n-type semiconductor 612 → p-type semiconductor 611 → n-type semiconductor 612" between the source (S) and drain (D). The first field-effect transistor Nch61 has three electrodes: drain (D), source (S), and gate (G). The drain (D) and source (S) are each connected to the n-type semiconductor 612. The source (S) is connected not only to the n-type semiconductor 612 but also to the p-type semiconductor 611. The gate (G) is, for example, made of metal and is connected to the p-type semiconductor 611 via an oxide insulating film 613.

[0029] A voltage is applied between the drain (D) and source (S) with drain (D)+ polarity (positive polarity), and a voltage is also applied between the gate (G) and source (S) with gate (G)+ polarity (positive polarity). As shown in Figure 3, electrons are attracted to the p-type semiconductor 611 (inversion layer 614) directly beneath the oxide insulating film 613, and the p-type semiconductor 611 changes to an n-type semiconductor (inverts). Then, a current flows from the drain (D) to the source (S).

[0030] On the other hand, the second field-effect transistor Pch71 and the fourth field-effect transistor Pch91, which are p-channel MOS-FETs, are constructed by joining a "p-type semiconductor → n-type semiconductor → p-type semiconductor" between the source (S) and drain (D). When a voltage is applied between the drain (D) and source (S) with source (S) + polarity (positive polarity), and a voltage is applied between the gate (G) and source (S) with gate (G) - polarity (negative polarity), current flows from the source (S) to the drain (D).

[0031] As mentioned above, the first field-effect transistor Nch61 is constructed by joining a p-type semiconductor 611 and an n-type semiconductor 612. Furthermore, the source (S) is connected not only to the n-type semiconductor 612 but also to the p-type semiconductor 611. Therefore, when a voltage with source (S)+ polarity (positive polarity) is applied between the drain (D) and source (S), current flows from the source (S) to the drain (D), as shown in Figure 4. This is due to the action of a body diode (parasitic diode) formed between the drain (D) and source (S) because the field-effect transistor (FET) is structurally composed of a p-type semiconductor and an n-type semiconductor joined together.

[0032] On the other hand, in the second field-effect transistor Pch71 and the fourth field-effect transistor Pch91, which are p-channel MOS-FETs, when a voltage is applied between the drain (D) and source (S) with drain (D)+ polarity (positive polarity), current flows from the drain (D) to the source (S) due to the flapping of the body diode.

[0033] <Operation of non-polarized circuit A (when connected in a forward direction)> Next, the operation of the non-polar circuit A in Embodiment Example 1 of the present invention will be described. As shown in Figure 5, when the power supply 1 is connected in order to the non-polar circuit A, current flows through the path "power supply 1 → first semiconductor light-emitting element 4 on the first circuit 31 → first field-effect transistor Nch61 → load 2 → fourth field-effect transistor Pch91 → second semiconductor light-emitting element 5 → power supply 1".

[0034] In the first field-effect transistor Nch61, power supply 1 applies a voltage between the drain (D) and source (S) with source (S) positive polarity, causing current to flow from source (S) to drain (D) due to the body diode's action.

[0035] Furthermore, in the fourth field-effect transistor Pch91, power supply 1 applies a voltage between the drain (D) and source (S) with drain (D)+ polarity (positive polarity), causing current to flow from the drain (D) to the source (S) due to the body diode's swiping action.

[0036] <Operation of non-polarized circuit A (in case of reverse connection)> Next, as shown in Figure 6, when power supply 1 is reverse-connected to the non-polarized circuit A, current flows through the path "power supply 1 → first semiconductor light-emitting element 4 on the third circuit 33 → third field-effect transistor Nch81 → load 2 → second field-effect transistor Pch71 → second semiconductor light-emitting element 5 → power supply 1".

[0037] In the third field-effect transistor Nch81, power supply 1 applies a voltage between the drain (D) and source (S) with source (S) positive polarity, causing current to flow from source (S) to drain (D) due to the body diode's action.

[0038] Furthermore, in the second field-effect transistor Pch71, power supply 1 applies a voltage between the drain (D) and source (S) with drain (D)+ polarity (positive polarity), causing current to flow from the drain (D) to the source (S) due to the body diode's action.

[0039] As described above, when the polarity of power supply 1 is connected in the forward direction, the gate of the first field-effect transistor Nch61 (indicated as "G" in Figure 1) is connected to the first circuit 31 at a voltage higher than that of the first semiconductor light-emitting element 4 on the first circuit 31. Also, the gate of the fourth field-effect transistor Pch91 is connected to the third circuit 33 at a voltage lower than that of the first semiconductor light-emitting element 4 on the third circuit 33. Furthermore, when the polarity of power supply 1 is connected in the reverse direction, the gate of the third field-effect transistor Nch81 is connected to the third circuit 33 at a voltage higher than that of the first semiconductor light-emitting element 4. Also, the gate of the second field-effect transistor Pch71 is connected to the first circuit 31 at a voltage lower than that of the first semiconductor light-emitting element 4 on the first circuit 31. In other words, when power supply 1 is supplied with voltage, the gate of the first field-effect transistor Nch61 or the gate of the third field-effect transistor Nch81 will have a higher potential than the corresponding source by the amount of the voltage drop across the first semiconductor light-emitting element 4 and the second semiconductor light-emitting element 5. On the other hand, the gate of the second field-effect transistor Pch71 or the gate of the fourth field-effect transistor Pch91 will have a lower potential than the corresponding source by the amount of the voltage drop across the first semiconductor light-emitting element 4 and the second semiconductor light-emitting element 5. Therefore, when power supply 1 is connected in the forward direction, the first field-effect transistor Nch61 and the fourth field-effect transistor Pch91 will turn "ON", and conduction will occur between the drain (D) and source (S). Also, when power supply 1 is connected in the reverse direction, the second field-effect transistor Pch71 and the third field-effect transistor Nch81 will turn "ON", and conduction will occur between the drain (D) and source (S).

[0040] By configuring the non-polarized circuit A of Embodiment Example 1 of the present invention in this way, it becomes unnecessary to pay attention to polarity when connecting the power supply 1, which is convenient.

[0041] Furthermore, by using a field-effect transistor in the circuit instead of a diode bridge, voltage drop and power loss can be minimized.

[0042] Furthermore, in order to turn on a field-effect transistor and conduct between the drain (D) and source (S), the gate potential must be higher than the source potential. In the non-polar circuit A according to Example 1 of this embodiment, the forward voltage (V) of the first semiconductor light-emitting element 4 and the second semiconductor light-emitting element 5 F )·Since the voltage drop is used to lower the potential of the source, the efficiency is good when the load 2 connected to the non-polar circuit A is a semiconductor light-emitting element substrate.

[0043] (Example 2 of this embodiment) In the non-polar circuit A of Embodiment Example 1 of the present invention described above, a configuration using an N-channel field-effect transistor and a P-channel field-effect transistor was shown, but the invention is not limited to this configuration. In Embodiment Example 2 of the present invention described below, a non-polar circuit B configured using only an N-channel field-effect transistor will be explained.

[0044] <Configuration of non-polarized circuit B> As shown in Figure 7, the non-polarized circuit B includes a first circuit 31 to which the positive terminal of power supply 1 is connected at one end and one end of load 2 is connected at the other end, and a third circuit 33 to which the negative terminal of power supply 1 is connected at one end and the other end of load 2 is connected at the other end. Note that Figure 7 shows the case where the polarity of power supply 1 is connected in the forward direction, and the arrangement of each element will be explained based on that.

[0045] On the first circuit 31, the first semiconductor light-emitting element 4 is arranged in series with its cathode (indicated as "K" in Figure 7) facing downwards in voltage direction. And on the third circuit 33, anode The first semiconductor light-emitting element 4 is arranged in series so that it faces (indicated as "A" in Figure 7). In addition, the second semiconductor light-emitting element 5 is arranged in parallel with the first semiconductor light-emitting element 4 on the first circuit 31 and the third circuit 33, respectively, so as to face the opposite direction to the first semiconductor light-emitting element 4.

[0046] A first field-effect transistor Nch61 is connected in series to the first circuit 31 at a voltage lower than that of the first semiconductor light-emitting element 4, with its drain connected in the direction of the lower voltage and its source connected in the direction of the higher voltage.

[0047] The gate of the first field-effect transistor Nch61 is connected to the first circuit 31 at a voltage higher than that of the first semiconductor light-emitting element 4.

[0048] The drain of the second field-effect transistor Nch101 is connected to the first circuit 31 at a voltage lower than that of the first semiconductor light-emitting element 4, and the source of the second field-effect transistor Nch101 is connected to the third circuit 33 via the second circuit 32 at a voltage lower than that of the load 2.

[0049] The gate of the second field-effect transistor Nch101 is connected to the second circuit 32 through the fifth circuit 35.

[0050] The fifth circuit 35 is connected to the third circuit 33 at a voltage higher than that of the first semiconductor light-emitting element 4, and at a voltage lower than that of the drain of the third field-effect transistor Nch81, which will be described later.

[0051] On the fifth circuit 35, a resistor 131 and a constant voltage element 121 are arranged in series, in order of proximity to the third circuit 33. The constant voltage element 121 is positioned so that its anode (indicated as "A" in Figure 7) faces towards the second circuit 32. The resistance value of the resistor 131 on the fifth circuit 35 is, for example, 1 (MΩ). The constant voltage element 121 on the fifth circuit 35 applies an appropriate voltage to the gate of the second field-effect transistor 101 without applying an excessive voltage, thereby turning the second field-effect transistor 101 "ON". In order to generate a constant voltage in the constant voltage element 121, a small current needs to flow through it. Therefore, the resistor 131 plays the role of consuming the current flowing on the fifth circuit 35.

[0052] A resistor 141 is provided on the sixth circuit 36, which connects the point on the second circuit 32 between the source of the second field-effect transistor 101 and the connection point of the fifth circuit 35, and the point on the fifth circuit 35 between the connection point of the gate of the second field-effect transistor 101 and the constant voltage element 121. The resistance value of this resistor 141 is, for example, 1 (MΩ). This resistor 141 serves to dissipate the charge accumulated in the second field-effect transistor 101. By dissipating the charge, it is possible to prevent the second field-effect transistor 101 from accidentally turning "ON" and causing conduction between the drain and source.

[0053] A third field-effect transistor Nch81 is installed in series on the third circuit 33 at a voltage lower than that of load 2, with its source connected in the direction of higher voltage and its drain connected in the direction of lower voltage.

[0054] The gate of the third field-effect transistor Nch81 is connected to the third circuit 33 through the fourth circuit 34.

[0055] The fourth circuit 34 is connected to the first circuit 31 at a voltage lower than that of the first semiconductor light-emitting element 4, and at a voltage higher than that of the source of the first field-effect transistor Nch61.

[0056] On the fourth circuit 34, a resistor 131 and a constant voltage element 121 are arranged in series, in order of proximity to the first circuit 31. The constant voltage element 121 is positioned so that its anode (indicated as "A" in Figure 7) faces towards the third circuit 33. The resistance value of the resistor 131 on the fourth circuit 34 is, for example, 1 (MΩ). The constant voltage element 121 on the fourth circuit 34 applies an appropriate voltage to the gate of the third field-effect transistor 81 without applying an excessive voltage, thereby turning the third field-effect transistor 81 "ON". In order to generate a constant voltage in the constant voltage element 121, a small current needs to flow through it. Therefore, the resistor 131 plays a role in consuming the current flowing on the fourth circuit 34.

[0057] A resistor 141 is provided on the seventh circuit 37, which connects the point on the third circuit 33 between the source of the third field-effect transistor 81 and the connection point of the fourth circuit 34, and the point on the fourth circuit 34 between the connection point of the gate of the third field-effect transistor 81 and the constant voltage element 121. The resistance value of this resistor 141 is, for example, 1 (MΩ). This resistor 141 serves to dissipate the charge accumulated in the third field-effect transistor 81. By dissipating the charge, it is possible to prevent the third field-effect transistor 81 from accidentally turning "ON" and causing conduction between the drain and source.

[0058] The source of the fourth field-effect transistor Nch111 is connected to the third circuit 33 at a voltage higher than that of the first semiconductor light-emitting element 4, and the drain of the fourth field-effect transistor Nch111 is connected to the first circuit 31 at a voltage higher than that of the load 2.

[0059] The gate of the fourth field-effect transistor Nch111 is connected to the third circuit 33 at a voltage lower than that of the first semiconductor light-emitting element 4.

[0060] <Operation of non-polarized circuit B (when connected in a forward direction)> Next, the operation of the non-polar circuit B in Embodiment Example 2 of the present invention will be described. As shown in Figure 8, when the power supply 1 is connected in order to the non-polar circuit B, current flows through the path "power supply 1 → first semiconductor light-emitting element 4 on the first circuit 31 → first field-effect transistor Nch61 → load 2 → third field-effect transistor Nch81 → second semiconductor light-emitting element 5 → power supply 1".

[0061] In addition, in the first field-effect transistor Nch61 and the third field-effect transistor Nch81, power supply 1 applies a voltage between the drain (D) and source (S) with source (S) + polarity (positive polarity), causing current to flow from source (S) to drain (D) due to the flapping of the body diode.

[0062] Furthermore, since the gate of the first field-effect transistor Nch61 is connected to the first circuit 31 at a voltage higher than that of the first semiconductor light-emitting element 4, its potential becomes higher than that of the source, and the first field-effect transistor Nch61 turns "ON".

[0063] Furthermore, when current flows on the fourth circuit 34, the constant voltage diode 121 applies a voltage to the gate of the third field-effect transistor Nch81, causing it to turn "ON".

[0064] <Operation of non-polarized circuit B (in reverse connection case)> Next, as shown in Figure 9, when power supply 1 is reverse-connected to the non-polarized circuit B, current flows through the path "power supply 1 → first semiconductor light-emitting element 4 on the third circuit 33 → fourth field-effect transistor Nch111 → load 2 → second field-effect transistor Nch101 → second semiconductor light-emitting element 5 → power supply 1".

[0065] In the fourth field-effect transistor Nch111, power supply 1 applies a voltage between the drain (D) and source (S) with source (S) positive polarity, causing current to flow from source (S) to drain (D) due to the body diode's action.

[0066] Furthermore, in the second field-effect transistor Nch101, power supply 1 applies a voltage between the drain (D) and source (S) with source (S) positive polarity, causing current to flow from source (S) to drain (D) due to the body diode's action.

[0067] Furthermore, when the polarity of power supply 1 is reversed, the gate of the fourth field-effect transistor Nch111 is connected to the third circuit 33 at a voltage higher than that of the first semiconductor light-emitting element 4. As a result, the potential becomes higher than that of the source, and the fourth field-effect transistor Nch111 turns "ON".

[0068] Furthermore, when current flows on the fifth circuit 35, the constant voltage diode 121 applies a voltage to the gate of the second field-effect transistor Nch101, causing it to turn "ON".

[0069] Although preferred embodiments of the present invention have been described above, it goes without saying that the non-polarized circuit according to the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the present invention. [Explanation of Symbols]

[0070] 1: power supply, 2: load, 31: 1st electrical circuit, 32: 2nd electrical circuit, 33: 3rd electrical circuit, 34: 4th electrical circuit, 35: 5th electrical circuit, 36: 6th electrical circuit, 37: 7th electrical circuit, 4: First semiconductor light-emitting element, 5: Second semiconductor light-emitting element, 61: First field-effect transistor Nch, 611: p-type semiconductor, 612: n-type semiconductor, 613: oxide insulating film, 614: inversion layer, 71: Second field-effect transistor Pch, 81: Third field-effect transistor Nch, 91: Fourth field-effect transistor Pch 101: Second field-effect transistor Nch, 111: Fourth field-effect transistor Nch, 121: Constant voltage semiconductor device, 131: Resistance, 141: Resistor

Claims

1. A non-polarized circuit that operates regardless of whether the power supply is connected in forward or reverse. A first circuit in which the positive terminal of the power supply is connected to one end and one end of the load is connected to the other end, The circuit comprises a third circuit to which the negative terminal of the power supply is connected at one end and the other end of the load is connected at the other end. A first semiconductor light-emitting element is provided in series on the first circuit such that its cathode faces in the direction of the lower voltage. The first semiconductor light-emitting element is arranged in series on the third circuit such that its anode faces in the direction of the lower voltage. A second semiconductor light-emitting element is provided in parallel with the first semiconductor light-emitting element, in a orientation opposite to that of the first semiconductor light-emitting element. A first field-effect transistor Nch is provided in series on the first circuit at a voltage lower than that of the first semiconductor light-emitting element, with its drain connected in the lower voltage direction and its source connected in the higher voltage direction. The source of the second field-effect transistor Pch is connected to the first circuit at a voltage lower than that of the first semiconductor light-emitting element. The drain of the second field-effect transistor Pch is connected to the third circuit at a position where the voltage is lower than that of the load. The gates of the first field-effect transistor Nch and the second field-effect transistor Pch are connected to the first circuit at a voltage higher than that of the first semiconductor light-emitting element. A fourth field-effect transistor Pch is provided in series on the third circuit at a position where the voltage is lower than that of the load, with its drain connected in the direction of higher voltage and its source connected in the direction of lower voltage. The source of the third field-effect transistor Nch is connected to the third circuit at a position where its voltage is higher than that of the first semiconductor light-emitting element. The drain of the third field-effect transistor Nch is connected to the first circuit at a position where the voltage is higher than that of the load. A non-polarized circuit characterized in that the gates of the third field-effect transistor Nch and the fourth field-effect transistor Pch are connected to the third circuit at a voltage lower than that of the first semiconductor light-emitting element.

2. A non-polarized circuit that operates regardless of whether the power supply is connected in forward or reverse. A first circuit in which the positive terminal of the power supply is connected to one end and one end of the load is connected to the other end, The circuit comprises a third circuit to which the negative terminal of the power supply is connected at one end and the other end of the load is connected at the other end. A first semiconductor light-emitting element is provided in series on the first circuit such that its cathode faces in the direction of the lower voltage. The first semiconductor light-emitting element is arranged in series on the third circuit such that its anode faces in the direction of the lower voltage. A second semiconductor light-emitting element is provided in parallel with the first semiconductor light-emitting element, in a orientation opposite to that of the first semiconductor light-emitting element. A first field-effect transistor Nch is provided in series on the first circuit at a voltage lower than that of the first semiconductor light-emitting element, with its drain connected in the lower voltage direction and its source connected in the higher voltage direction. The gate of the first field-effect transistor Nch is connected to the first circuit at a voltage higher than that of the first semiconductor light-emitting element. The drain of the second field-effect transistor Nch is connected to the first circuit at a voltage lower than that of the first semiconductor light-emitting element. The source of the second field-effect transistor Nch is connected to the third circuit via the second circuit at a voltage lower than that of the load. The gate of the second field-effect transistor Nch is connected to the second circuit through the fifth circuit, The fifth circuit is connected to the third circuit at a position where the voltage is higher than that of the first semiconductor light-emitting element and lower than that of the drain of the third field-effect transistor Nch. On the fifth circuit, constant voltage semiconductor elements are provided in series such that their anodes face the direction of the second circuit. At a position on the third circuit where the voltage is lower than that of the load, the third field-effect transistor Nch is provided in series with its source connected in the direction of higher voltage and its drain connected in the direction of lower voltage. The gate of the third field-effect transistor Nch is connected to the third circuit through the fourth circuit. The fourth circuit is connected to the first circuit at a position where the voltage is lower than that of the first semiconductor light-emitting element and higher than that of the source of the first field-effect transistor Nch. On the fourth circuit, constant voltage semiconductor elements are provided in series such that their anodes face the direction of the third circuit. The source of the fourth field-effect transistor Nch is connected to the third circuit at a position where its voltage is higher than that of the first semiconductor light-emitting element. The drain of the fourth field-effect transistor Nch is connected to the first circuit at a position where the voltage is higher than that of the load. A non-polarized circuit characterized in that the gate of the fourth field-effect transistor Nch is connected to the third circuit at a voltage lower than that of the first semiconductor light-emitting element.

Images