JP2010081336A - Flicker circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flicker circuit in which cost reduction is attained by reducing power consumption and decreasing the number of components. <P>SOLUTION: As a first terminal of a light-emitting thyristor 20, an anode terminal is connected to a power source VDD via a resistor 13 and connected to a ground via a capacitor 15 and as a second terminal thereof, a cathode terminal is connected to the ground via a resistor 14. As a third terminal thereof, a gate terminal is connected to the connection center of a series circuit of a resistor 11 and a resistor 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blinking circuit that blinks a light emitting element.

  Conventionally, as a circuit for driving the light emitting element to blink, there is, for example, an astable multivibrator circuit. Hereinafter, it demonstrates according to a figure. FIG. 11 shows a blinking circuit using a conventional astable multivibrator circuit. In FIG. 11, 51 to 54 are resistors, 55 is an LED (light emitting diode), 56 and 57 are capacitors, 58 and 59 are NPN transistors, and 61 and 62 are diodes.

  One ends of the resistors 51 to 54 are connected to the power supply VDD, the other end of the resistor 51 is connected to the anode of the LED 55, and the cathode of the LED 55 is connected to one end of the capacitor 56 and the collector of the transistor 58. The other end of the resistor 52 is connected to the other end of the capacitor 56 and is also connected to the base of the transistor 59 and the cathode of the diode 62. The other end of the resistor 53 is connected to one end of the capacitor 57, and is connected to the base of the transistor 58 and the cathode of the diode 61. The other end of the resistor 54 is connected to the other end of the capacitor 57 and to the collector of the transistor 59. The emitters of the transistors 58 and 59 and the cathodes of the diodes 61 and 62 are connected to the ground.

  Next, the operation will be described. Assume that the transistor 58 is off and the transistor 59 is on. At this time, the collector potential of the transistor 59 is approximately 0 V, and a collector current flows through the resistor 54. At this time, a charging current flows into the capacitor 57 from the power supply VDD via the resistor 53, and the other end of the capacitor 57 is approximately 0 V. Therefore, the capacitor 57 has a time constant determined by the resistance value of the resistor 53 and the capacitance value of the capacitor 57. It will be charged.

  At this time, when the charging voltage of the capacitor 57 reaches a level at which a base current is generated in the transistor 58, the transistor 58 is turned on and the collector potential becomes substantially 0V, generating a collector current. This produces a forward current flowing through. The LED 55 is lit by this forward current. At this time, the collector potential of the transistor 58 is lowered to about 0 V, so that the charge charged in the capacitor 56 is discharged through the diode 62, and then the capacitor 56 is charged from the power supply VDD through the resistor 52. To go. Accordingly, when the base potential of the transistor 59 reaches a predetermined voltage, the transistor 59 is turned on again.

  Thus, the transistor 59 is turned off when the transistor 58 of the circuit of FIG. 11 is turned on, and the transistor 58 is turned off when the transistor 59 is turned on, so that the on and off states are alternately switched and inverted. It will oscillate. Accordingly, forward current is intermittently generated in the LED 55 connected to the collector of the transistor 58, and the LED 55 performs blinking operation at a predetermined cycle.

For example, JP-A-6-268485 discloses a blinking circuit using such an unstable multivibrator circuit.
JP-A-6-268485

  As described above, in the conventional blinking circuit shown in FIG. 11, the transistor 59 is turned off when the transistor 58 is turned on, and the transistor 58 is turned off when the transistor 59 is turned on. As a result, the LED 55 connected to the collector of the transistor 58 intermittently generates a forward current, and the LED 55 blinks at a predetermined cycle. In the ON state, the drive current is supplied from the power supply VDD via the resistor 51. In addition, the transistor 59 is also in the ON state even when the LED 55 is OFF, so the drive current is supplied from the power supply VDD via the resistor 54. Collector current is supplied.

  Thus, when viewed from the power supply VDD, the power supply current always exceeds the forward current of the LED 55 regardless of whether the LED 55 is turned on or off, and as a result, the current consumption becomes large. was there.

  In addition, when a power supply VDD having a limited electric capacity such as a dry battery or a battery is used, the battery of the power supply VDD is consumed by bearing a forward current when the LED is driven and a reactive current that continues to flow even when the LED is turned off. There was a problem that it became intense and could not be operated for a long time. In addition, since the forward current is supplied from the battery in the lighting state of the LED, if the battery is exhausted and its internal resistance increases, the battery voltage decreases when attempting to supply the forward current, There was also a problem that the operation of the LED blinking circuit could not be continued and the capacity of the battery could not be used up.

  The above-described conventional blinking circuit shown in FIG. 11 has been shown as an example in which it is configured using individual components such as transistors, resistors, and capacitors. However, a configuration using a drive circuit integrated using a silicon IC chip is also possible. Is possible. In this case, an oscillation circuit that performs an analog circuit operation is used, and LED driving is performed at a predetermined cycle using a digital circuit such as a counter circuit based on a clock signal generated by the oscillation circuit.

  As described above, the blinking circuit of the conventional configuration requires a large number of parts other than the LED, which is a light emitting element, or a dedicated driving IC using a silicon IC chip. This was a limitation in realizing the provided flashing device at a low cost.

  An object of the present invention is to provide a flashing circuit that reduces the power consumption and reduces the number of parts to reduce the cost.

  In order to solve the above problems, a blinking circuit according to the present invention includes a power supply unit that supplies power, a charging unit that performs charging by being supplied with power from the power supply unit, and a voltage in the charging unit at a predetermined value. And a light emitting element circuit through which a current flows when the light reaches the light emitting element, and the charging unit is discharged when a current flows through the light emitting element circuit.

  According to the present invention having the above-described configuration, the current supplied to the charging unit is used as the current for lighting the light emitting element, so that the current supplied from the power supply unit may be very small. Further, since the active element required for the blinking circuit of the present invention is only a light emitting element, it is not necessary to separately provide a semiconductor chip or the like, and a low-cost circuit can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure. FIG. 1 is a circuit diagram showing a flashing circuit according to Embodiment 1 of the present invention.

  In FIG. 1, reference numeral 1 denotes a flashing circuit. The flashing circuit 1 is provided with a light-emitting thyristor 10 as a three-terminal switch element, resistors 11 to 14, and a capacitor 15. One ends of the resistors 11 and 13 are connected to the power supply VDD, the other end of the resistor 13 is connected to one end of the capacitor 15 and the anode of the light emitting thyristor 10, and the other end of the capacitor 15 is connected to the ground. The other end of the resistor 11 is connected to one end of the resistor 12 and the gate terminal of the light emitting thyristor 10. The other end of the resistor 12 is connected to the ground. The cathode of the light emitting thyristor 10 is connected to the ground via a resistor 14.

  That is, the anode terminal which is the first terminal of the light emitting thyristor 10 is connected to the power supply VDD via the resistor 13 and is connected to the ground via the capacitor 15, and the cathode terminal which is the second terminal is connected via the resistor 14. The gate terminal, which is the third terminal, is connected to the ground, and is connected to the connection center of the series circuit of the resistors 11 and 12.

  FIG. 2 is a configuration diagram showing the configuration of the light-emitting thyristor 10 shown in FIG. FIG. 2A shows a circuit symbol, and the light-emitting thyristor 10 has three terminals of an anode terminal A, a cathode terminal K, and a gate terminal G.

  FIG. 2B is a diagram showing a cross-sectional structure of the light emitting thyristor. The light emitting thyristor 10 shown in the figure is formed by using a GaAs wafer base material and epitaxially growing a predetermined crystal on the upper layer of the base material by a known MO-CVD (Metal Organic-Chemical Vapor Deposition) method. First, after a predetermined buffer layer (not shown) is epitaxially grown, an N-type layer 103 containing an N-type impurity in an AlGaAs base, a P-type layer 102 containing an N-type impurity, and an N-type impurity A wafer having an NPN three-layer structure in which an N-type layer 101 containing N is laminated in order is formed.

  Next, a P-type impurity region 104 is selectively formed in a part of the uppermost N-type layer 101 using a known photolithography method. Further, element isolation is performed by forming a groove by a known dry etching method. Further, a part of the N-type layer 103 which is the lowermost layer of the thyristor is exposed during the etching process, and a metal wiring is formed in the region 103 to form a cathode electrode. At the same time, an anode electrode and a gate electrode are formed in the P-type region 104 and the N-type region 101, respectively.

  FIG. 2C shows another embodiment of the light emitting thyristor. In the configuration of FIG. 2 (c), a GaAs wafer substrate is used, and a predetermined crystal is epitaxially grown on the upper layer of the substrate by a known MO-CVD method. First, after a predetermined buffer layer (not shown) is epitaxially grown, an N-type layer 103 containing an N-type impurity in an AlGaAs substrate, a P-type layer 102 containing a P-type impurity, and an N-type impurity are added. A wafer having a four-layer structure of PNPN in which an N-type layer 101 contained and a P-type layer 105 containing a P-type impurity and laminated is sequentially formed.

  Further, element isolation is performed by forming a groove using a known dry etching method. In the etching process, a part of the N-type region 103 which is the lowermost layer of the thyristor is exposed, and a metal wiring is formed in the region 103 to form a cathode electrode. Similarly, a part of the P-type region 105 that is the uppermost layer is exposed, and metal wiring is formed in the region 105 to form an anode electrode. At the same time, a gate electrode is formed in the N-type region 101.

  FIG. 2D is an equivalent circuit of a light-emitting thyristor drawn in contrast to FIGS. 2B and 2C. The light-emitting thyristor 10 includes a PNP transistor 111 and an NPN transistor 112. The emitter of the PNP transistor 111 corresponds to the anode terminal A of the light-emitting thyristor 10, and the base of the PNP transistor 111 corresponds to the gate terminal G of the light-emitting thyristor 10. The gate terminal is also connected to the collector of the NPN transistor 112. The collector of the PNP transistor 111 is connected to the base of the NPN transistor 112, and the emitter of the NPN transistor 112 corresponds to the cathode terminal K of the light emitting thyristor 10.

  The light-emitting thyristor 10 shown in FIG. 2 has an AlGaAs layer formed on a GaAs wafer substrate, but is not limited to this, and uses materials such as GaP, GaAsP, and AlGaInP. Alternatively, a material such as GaN or AlGaN may be formed on a sapphire substrate.

  Next, the operation of the first embodiment will be described. FIG. 3 is a circuit diagram for explaining the operation of the blinking circuit according to the first embodiment, and FIG. 4 is a time chart showing the operation of the blinking circuit according to the first embodiment. In FIG. 3, reference numeral 19 surrounded by a broken line indicates the inside of a power supply VDD made of a battery or the like, where VDD is a voltage generation unit of the battery, and r0 is a modeled internal resistance of the power supply. . In FIG. 3, the resistance values of the resistors 11 to 14 are indicated as R1, R2, R3, and Rk, and the capacitance value of the capacitor 15 is indicated as C in the drawing.

  Further, the anode potential of the light emitting thyristor 10 is denoted as Va, the gate potential is denoted as Vg, and the cathode current is denoted as Ik. Further, the current flowing through the resistors 11 and 12 is denoted by I1, and the charging current flowing through the capacitor 15 via the resistor 13 is denoted by I2 and shown in the figure. 4 is the anode potential waveform of the light emitting thyristor 10 and changes in a sawtooth shape reflecting the off state and on state of the light emitting thyristor 10. In the figure, T1 indicates an off period of the light emitting thyristor 10, and T2 indicates an on period of the light emitting thyristor 10.

  Now, when the light-emitting thyristor 10 is in the off state, the current at its anode terminal is substantially zero, so the current I2 indicated by the broken arrow flows as the charging current of the capacitor 15 via the resistor 13, and the charging current causes The potential across the capacitor 15 rises.

  4 indicates the gate potential waveform of the light-emitting thyristor 10. When the light-emitting thyristor 10 is in the off state, the resistor 11 and the resistor 12 maintain the potential that divides the power supply voltage VDD. In the ON state, the waveform rapidly decreases as the gate-cathode potential difference becomes substantially 0V.

  Now, when the light-emitting thyristor 10 is in the off state, as shown in the upper part of FIG. 4, the anode potential Va is in a rising process and is higher than the gate potential Vg by the threshold voltage Vt described in the figure. Suppose that The threshold voltage Vt is the anode-gate voltage of the light emitting thyristor 10 shown in FIG. 2, and corresponds to the forward voltage of the PN junction between the anode and gate shown in FIGS. 2 (b) and 2 (c). is there.

  At this time, a current flowing from the anode terminal of the light emitting thyristor 10 through the gate terminal is generated, and the light emitting thyristor 10 is turned on. As a result, the anode potential of the light-emitting thyristor 10 is suddenly lowered, and the charge charged in the capacitor 15 is discharged through a loop indicated by a broken-line arrow Ik passing through the anode, cathode, and resistor 14 of the light-emitting thyristor 10.

  As a result, as shown in the lower waveform of FIG. 4, the discharge current Ik flows as shown in the period T2, and the voltage across the capacitor 15 is lowered accordingly, and a waveform in which the anode potential Va is rapidly lowered is obtained. As the accumulated charge in the capacitor 15 becomes substantially zero due to the discharge, the light emitting thyristor 10 is turned off when the anode current of the light emitting thyristor 10 (which is substantially equal to the cathode current) becomes substantially zero. By repeating the above process, the current Ik is intermittently generated in the light emitting thyristor 10.

  Now, as described with reference to FIG. 2, the light-emitting thyristor 10 shown in FIG. 3 is configured by using a light-emitting material such as AlGaAs, and by flowing a current between the anode and the cathode in the ON state, An optical output corresponding to the current value can be obtained. In addition, when the light-emitting thyristor 10 is in an off state, no current flows between the anode and the cathode, so that the light-emitting thyristor 10 does not emit light. Operation will be performed.

In FIG. 3, the peak value (I2peak) of the charging current to the capacitor 15 is determined according to the power supply voltage VDD and the resistance value R3 of the resistor 13,
I2peak = VDD / (r0 + R3)
Can be estimated. When the blinking cycle of the light emitting thyristor 10 is slow enough to be visually discerned, the time constant circuit composed of the resistance value R3 of the resistor 13 and the capacitance value C of the capacitor 15 becomes a large value, and the resistance value R3 of the resistor 13 The peak current I2peak can be reduced by increasing the value.

  On the other hand, in the discharging process of the capacitor 15, as shown in FIG. 3, the discharging current flows in a loop of Ik current indicated by a broken line. The current Ik is mainly due to the electric charge accumulated in the capacitor 15, and is different from the current supplied from the voltage source indicated by 19. The current supplied from the voltage source indicated by 19 is the sum of the current I1 and the current I2.

Here, the current I1 flowing through the resistor 11 and the resistor 12 is calculated from the resistance values R1 and R2 of the resistors 11 and 12, respectively. I1 = VDD / (R1 + R2)
Therefore, by setting the resistance values R1 and R2 to be large, the value of the current flowing through the resistors 11 and 12 can be reduced to a level that can be ignored depending on the purpose.

  As a result, the current supplied from the voltage source 19 may be a minute current value, and its peak value can be significantly reduced. Therefore, even if the power source 19 is a dry battery, for example, and its internal resistance r0 greatly increases after it is consumed, the flashing circuit 1 shown in FIG. 3 can continue the flashing operation, and the stored energy of the dry battery can be reduced. It is possible to make it blink for a long time by making the best use.

  As described above in detail, in the blinking circuit 1 according to the first embodiment, the current supplied from the voltage source may be a minute current value, and the peak value can be remarkably reduced. Therefore, even if the power source is, for example, a dry battery and the internal resistance greatly increases after it is consumed, the blinking circuit 1 shown in the first embodiment can continue the blinking operation, and the accumulated energy of the dry battery can be maximized. It can be used for a long time to blink for a long time.

  In the first embodiment, the light emitting thyristor 10 is the only active element required for the blinking circuit 1, and it is not necessary to prepare a separate semiconductor IC chip or the like, and a desired blinking circuit can be configured at a very low cost. The effect is obtained.

  Next, the blinking circuit of Example 2 will be described. FIG. 5 is a circuit diagram showing a blinking circuit according to the second embodiment. In FIG. 5, the flashing circuit 2 of the second embodiment is provided with a light emitting thyristor 20 as a three-terminal switch element, resistors 21 to 24, and a capacitor 25.

  One end of each of the resistors 21 and 24 is connected to the power supply VDD, the other end of the resistor 21 is connected to one end of the resistor 22 and the gate terminal of the light emitting thyristor 20, and the other end of the resistor 22 is connected to the ground. The other end of the resistor 24 is connected to the anode terminal of the light emitting thyristor 20. One end of the capacitor 25 is connected to the power supply VDD, the other end of the capacitor 25 is connected to the cathode terminal of the light emitting thyristor 20 and one end of the resistor 23, and the other end of the resistor 23 is connected to the ground.

  That is, the anode terminal which is the first terminal of the light emitting thyristor 20 is connected to the power supply VDD via the resistor 24, the cathode terminal which is the second terminal is connected to the connection center between the capacitor 25 and the resistor 23, and the third terminal The gate terminal is connected to the connection center of the series circuit of the resistor 21 and the resistor 22.

  FIG. 6 is a diagram showing a configuration of the light emitting thyristor 20 shown in FIG. FIG. 6A shows a circuit symbol of the light-emitting thyristor 20, which includes three terminals: an anode terminal A, a cathode terminal K, and a gate terminal G. FIG. 6B is a diagram showing a cross-sectional structure of the light-emitting thyristor shown in FIG.

  The light emitting thyristor 20 shown in FIG. 6B is formed by using a GaAs wafer base material and epitaxially growing a predetermined crystal on the upper layer of the base material by a known MO-CVD method. First, after a predetermined buffer layer (not shown) is epitaxially grown, an N-type layer 103 containing an N-type impurity in an AlGaAs base, a P-type layer 102 containing an N-type impurity, and an N-type impurity A wafer having an NPN three-layer structure in which an N-type layer 101 containing N is laminated in order is formed.

  Next, a P-type impurity region 104 is selectively formed in a part of the uppermost N-type layer 101 using a known photolithography method. Further, element isolation is performed by forming a groove by a known dry etching method. Further, a part of the N-type region 103 which is the lowermost layer of the thyristor is exposed during the etching process, and a metal wiring is formed in the region 103 to form a cathode electrode. At the same time, an anode electrode and a gate electrode are formed in the P-type region 104 and the P-type region 102, respectively.

  FIG. 6C shows another embodiment of the light emitting thyristor. In this configuration, a GaAs wafer substrate is used, and a predetermined crystal is epitaxially grown on the upper layer of the substrate by a known MO-CVD method. First, after a predetermined buffer layer (not shown) is epitaxially grown, an N-type layer 103 containing an N-type impurity in an AlGaAs substrate, a P-type layer 102 containing a P-type impurity, and an N-type impurity are added. A wafer having a four-layer structure of PNPN in which an N-type layer 101 contained and a P-type layer 105 containing a P-type impurity and laminated is sequentially formed.

  Further, element isolation is performed by forming a groove using a known dry etching method. In the etching process, a part of the N-type region 103 which is the lowermost layer of the thyristor is exposed, and a metal wiring is formed in the region 103 to form a cathode electrode. Similarly, a part of the P-type region 105 that is the uppermost layer is exposed, and metal wiring is formed in the region 105 to form an anode electrode. At the same time, a gate electrode is formed on the exposed portion of the P-type region 102.

  FIG. 6D is an equivalent circuit of a light-emitting thyristor drawn in contrast to FIGS. 6B and 6C. The light emitting thyristor 20 is composed of a PNP transistor 111 and an NPN transistor 112. The emitter of the PNP transistor 111 corresponds to the anode terminal A of the light emitting thyristor 20, and the base of the NPN transistor 112 corresponds to the gate terminal G of the light emitting thyristor 20. The terminal is also connected to the collector of the PNP transistor 111. The base of the PNP transistor 111 is connected to the collector of the NPN transistor 112, and the emitter of the NPN transistor 112 corresponds to the cathode terminal K of the light emitting thyristor 20.

  The light-emitting thyristor 20 shown in FIG. 6 has an AlGaAs layer formed on a GaAs wafer substrate, but is not limited to this, and a material such as GaP, GaAsP, or AlGaInP may be used. Alternatively, a material such as GaN or AlGaN may be formed on a sapphire substrate.

  Next, the operation of the second embodiment will be described. FIG. 7 is a circuit diagram for explaining the operation of the blinking circuit of the second embodiment, and FIG. 8 is a time chart showing the operation of the second embodiment. In FIG. 7, reference numeral 19 surrounded by a broken line indicates the inside of a power supply VDD made of a battery or the like, where VDD is a voltage generation unit of the battery, and r0 indicates a model of the internal resistance of the power supply. Yes.

  In FIG. 7, resistance values of the resistors 21 to 24 are shown as R1, R2, R3, and Ra, and a capacitance value of the capacitor 25 is shown as C in the drawing. Further, the cathode potential of the light emitting thyristor 20 is denoted as Vk, the gate potential is denoted as Vg, and the anode current is denoted as Ia. Further, the current flowing through the resistor 21 and the resistor 22 is denoted as I1, and the charging current flowing through the capacitor 25 via the resistor 23 is denoted as I2 in the figure.

  The solid line portion of the upper waveform in FIG. 8 is the cathode potential waveform Vk of the light emitting thyristor 20 and changes in a sawtooth shape reflecting the off state and on state of the light emitting thyristor 20. In the figure, T1 indicates an off period of the light emitting thyristor 20, and T2 indicates an on period of the light emitting thyristor 20. Now, in the OFF state of the light emitting thyristor 20, the current at the cathode terminal is substantially zero, so the current I2 indicated by the broken line arrow in FIG. 7 flows as the charging current of the capacitor 25 via the resistor 23, The voltage across the capacitor 25 increases due to the charging current.

  8 is a gate potential waveform Vg of the light-emitting thyristor 20, and the light-emitting thyristor 20 is maintained at a potential at which the power supply voltage VDD is divided by the resistors 21 and 22 when the light-emitting thyristor 20 is turned off. In the ON state of 20, the waveform rapidly rises as the anode-gate potential difference of the light emitting thyristor 20 becomes approximately 0V.

  Now, when the light-emitting thyristor 20 is in the off state, the cathode potential Vk of the light-emitting thyristor 20 is in a decreasing process with the change of the charging current to the capacitor 25, and the threshold value shown in the figure below the gate potential Vg. It is assumed that the potential is lowered by the voltage Vt. The threshold voltage Vt is the voltage between the anode and the gate of the light emitting thyristor 20 shown in FIG. 6, and corresponds to the forward voltage of the PN junction between the gate and the cathode shown in FIGS. 6B and 6C. is there.

  At this time, a current flowing from the gate terminal of the light emitting thyristor 20 through the cathode terminal is generated, and the light emitting thyristor 20 is turned on. As a result, the cathode potential Vk of the light-emitting thyristor 20 is rapidly increased, and the charge charged in the capacitor 25 is discharged through the resistor 24, the anode and the cathode of the light-emitting thyristor 20 in the loop indicated by the broken line arrow Ia in FIG. It is done. As a result, as shown in the lower waveform of FIG. 8, a discharge current Ia flows as in period T2, and a waveform in which the voltage across the capacitor 25 decreases correspondingly and the cathode potential Vk rapidly increases is obtained.

  As the accumulated charge of the capacitor 25 becomes substantially zero due to the discharge, the light emitting thyristor 20 is turned off when the anode current of the light emitting thyristor 20 (which is substantially equal to the cathode current) becomes substantially zero. By repeating the above process, a current Ia is intermittently generated in the light emitting thyristor 20.

  Now, as described with reference to FIG. 6, the light-emitting thyristor 20 used in the present embodiment is configured using a light-emitting material such as AlGaAs, and a current flows between the anode and the cathode in the on state. An optical output corresponding to the current value can be obtained. In addition, since no current flows between the anode and the cathode when the light emitting thyristor 20 is in the off state, there is no light emission by the light emitting thyristor 20, and as a result, the light emitting thyristor 20 blinks in accordance with the current waveform between the anode and cathode. Will be done.

In FIG. 7, the peak value (I2peak) of the charging current to the capacitor 25 is determined according to the power supply voltage VDD and the resistance value R3 of the resistor 23.
I2peak = VDD / (r0 + R3)
Can be estimated. When the blinking cycle of the light emitting thyristor is slow enough to be visually discerned, the time constant circuit composed of the resistance value R3 and the capacitance value C of the capacitor 25 becomes a large value, and the resistance value R3 also becomes a large value. The current I2peak can be reduced.

On the other hand, in the discharging process of the capacitor 25, as shown in FIG. 7, a discharging current flows in a loop of Ia current indicated by a broken line, and this current is mainly due to the electric charge accumulated in the capacitor 25. This is different from the current supplied from the voltage source shown in FIG. The current supplied from the voltage source indicated by 19 is the sum of the current I1 and the current I2. Here, the current I1 flowing through the resistors 21 and 22 is changed from the respective resistance values R1 and R2 to I1 = VDD / (R1 + R2).
Therefore, by setting the resistance values R1 and R2 to be large, the value of the current flowing through the resistance values R1 and R2 can be reduced to a level that can be ignored depending on the intended purpose.

  As a result, the current supplied from the voltage source 19 may be a minute current value, and its peak value is extremely small. Therefore, even if the power source 19 is a dry battery, for example, and its internal resistance r0 greatly increases after it is consumed, the flashing circuit shown in FIG. 7 can continue the flashing operation, and the stored energy of the dry battery can be reduced. It is possible to make it blink for a long time by making the best use.

  As described above in detail, in the second embodiment, in the blinking circuit using the light-emitting thyristor 20, the current supplied from the voltage source may be a minute current value, and the peak value thereof should be significantly reduced. Can do. Therefore, even if the power source is, for example, a dry battery, and the internal resistance greatly increases after it is consumed, the blinking operation of the second embodiment can be continued and the accumulated energy of the dry battery can be utilized to the maximum. Thus, it can be blinked for a long time.

  Further, the active element required for the flashing circuit may be only a thyristor, and it is not necessary to prepare a separate semiconductor IC chip or the like, and a desired flashing circuit can be configured at a very low cost.

  The blinking circuits 1 and 2 described in the first and second embodiments can be applied to indicators of various electronic devices, illumination devices, and warning security devices. FIG. 9 shows a multifunction printer. A multi-function printer (MFP) 200 shown in FIG. 9 includes a scanner unit 201 and a printer unit 202. The scanner unit 201 is provided with an operation panel 203, and the operation panel 203 is provided with an indicator 204. An operation panel 205 is also provided in the printer unit 202, and an indicator 206 is also provided on the operation panel 205. By using the blinking circuit of the present invention for the indicators 204 and 206, the operator can be notified.

  FIG. 10 is a side view showing the bicycle. In FIG. 10, a taillight 303 is attached to the rear fork portion 301 of the bicycle 300. By using the blinking circuit using the light emitting thyristor that emits red light according to the present invention for the taillight 303, it is possible to notify the following vehicle or the like while driving at night, and traffic accidents at night or the like. It helps to prevent in advance. Reference numeral 302 denotes wheel spokes.

FIG. 3 is a circuit diagram illustrating a flashing circuit according to the first embodiment. FIG. 3 is a configuration diagram showing a configuration of a light emitting thyristor in Example 1. FIG. 3 is a circuit diagram illustrating an operation of the blinking circuit according to the first embodiment. 3 is a time chart illustrating the operation of the flashing circuit according to the first embodiment. FIG. 6 is a circuit diagram illustrating a blinking circuit according to a second embodiment. FIG. 6 is a configuration diagram showing a configuration of a light emitting thyristor in Example 2. FIG. 6 is a circuit diagram illustrating an operation of a flashing circuit according to a second embodiment. 6 is a time chart illustrating the operation of the flashing circuit according to the second embodiment. It is a perspective view which shows a multifunction printer. It is a side view which shows a bicycle. It is a circuit diagram which shows the blink circuit using the conventional unstable multivibrator circuit.

Explanation of symbols

1, 2 Flashing circuit 10, 20 Light emitting thyristor 11, 12, 13, 14 Resistor 21, 22, 23, 24 Resistor 15, 25 Capacitor

Claims (7)

A power supply for supplying power;
A charging unit that performs charging by being supplied with power from the power source unit;
A light emitting element circuit in which a current flows through the light emitting element when the voltage in the charging unit reaches a predetermined value;
The blinking circuit, wherein the charging unit is discharged when a current flows through the light emitting element circuit. The flashing circuit according to claim 1, wherein the charging unit includes a capacitor. The blinking circuit according to claim 2, wherein the light emitting element circuit includes a light emitting thyristor. 4. The flashing circuit according to claim 3, wherein an anode terminal of the light emitting thyristor is connected to one end side of the capacitor, and a cathode terminal of the light emitting thyristor is connected to the other end side of the capacitor. Power supply,
A three-terminal switch element having a light emitting function;
A capacitor connected to the power source through a resistor,
The first terminal of the three-terminal switch element is connected to the power source via a resistor and connected to the ground via the capacitor, the second terminal is connected to the ground via a resistor, and the third terminal is connected to the resistor. A flashing circuit connected to the connection center of a series circuit. Power supply,
A three-terminal switch element having a light emitting function;
A capacitor connected to the power source,
The capacitor is connected to a resistor connected to ground,
The first terminal of the three-terminal switch element is connected to the power source, the second terminal is connected to the connection center of the capacitor and the resistor, and the third terminal is connected to the connection center of a series circuit of resistors. A flashing circuit that is characterized. 7. The flashing circuit according to claim 6, wherein the three-terminal switch element is a light emitting thyristor, the first terminal is an anode terminal, the second terminal is a cathode terminal, and the third terminal is a gate terminal.

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