JPH073005U - Different voltage automatic selection circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] Different types of electrical equipment that uses power sources of different voltages, which can sense high-voltage and automatically switch circuits according to the voltage to protect common high-voltage equipment An automatic voltage selection circuit is provided. [Structure] A trigger voltage in which an AC power supply is input to a rectifier 2 and a plurality of constant voltage diodes ZD _{1 to} ZD ₄ and a resistor R are connected in series so that a combined breakdown voltage value is an intermediate value between peak values of different voltages of the AC power supply. The generation circuit 3, a high-voltage short circuit 4 in which a thyristor SCR whose trigger voltage is a voltage across a resistor R of the trigger voltage generation circuit 3 and a high-voltage display light-emitting diode LED ₂ are connected, and a relay contact for different voltage selection. The relay RY and the relay circuit 5 in which the low-voltage display light emitting diode LED ₁ is connected in series are connected in parallel between the output DC voltage terminals of the rectifier 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 Automatically switches the input of the supply voltage in a single-phase power distribution system with different voltages or the power supply system of a mobile generator that is used for different voltage sharing type equipment, or the transformer tap switching in equipment that does not require an input transformer. Different voltage automatic selection circuit for performing

[0002]

[Prior art]

 Conventionally, a device that uses a single-phase power distribution system with different voltages or a power supply system of a mobile generator as a power supply has a switch that switches the circuit according to the voltage (high voltage / low voltage) of the power supply. ing. Conventionally, this switch is classified into a single-pole / double-throw switch that is suitable for the load current capacity, and a manual switching method that uses multiple relay switches. In the former method, there was a problem due to display misidentification manual operation or forgetting operation. In the latter method, the relay operates at 200 V, which is the mainstream, and the contact capacity and the load current capacity that are connected do not match (the closed contact NO during relay operation has a double capacity than the open contact NC). Inconsistent connection due to. In addition, the voltage indicator was usually attached separately, which increased costs.

[0003]

[Problems to be solved by the device]

 The problem to be solved by the present invention is to solve these drawbacks and to provide a different voltage automatic selection circuit that can more securely connect the input voltage more reliably and protect the high / low voltage common type device at low cost. .

[0004]

[Means for Solving the Problems]

 The gist of the present invention, which has solved such a problem, is to provide a trigger in which an AC power supply is input to a rectifier and a plurality of constant voltage diodes and resistors are connected in series so that a combined breakdown voltage value is an intermediate value between peak values of different voltages of the AC power supply. A high-voltage short circuit in which a voltage generation circuit, a thyristor that uses the voltage between the resistors of the trigger voltage generation circuit as the trigger voltage, and a high-voltage display light-emitting diode are connected in series, a relay with a different voltage selection relay contact, and a low-voltage display light emission. A different-voltage automatic selection circuit is characterized in that a relay circuit having a diode connected in series is connected in parallel between the output DC voltage terminals of the rectifier.

[0005]

[Action]

 AC power supplies having different voltage values are rectified by a rectifier and converted into DC voltage. This DC voltage is applied to the trigger voltage generating circuit, the high voltage short circuit, and the relay circuit that are connected in parallel. In the trigger voltage generation circuit, the combined breakdown voltage of multiple voltage regulator diodes is an intermediate value of the peak values of different voltage values, so no current flows if the AC power supply is low, and both ends of the resistance of this circuit There is no voltage difference between them. Therefore, the voltage between the gate triggers of the thyristors of the high voltage short circuit does not occur and the high voltage display light emitting diode does not light. Then, current flows only in the relay circuit, the low-voltage display light-emitting diode lights up, the relay operates, and the relay contact opens and closes to the low-voltage side.

Next, when the AC power supply has a high voltage, the peak value of the DC voltage of the trigger voltage generating circuit exceeds the combined breakdown voltage value of the constant voltage diode, and a current flows, so that a required trigger voltage is generated in the resistor. Therefore, the thyristor of the high-voltage short-circuit circuit is turned on, and the high-voltage display light emitting diode is lit up, and the short-circuit state is established. As a result, the operation of the relay circuit is stopped and the relay contact becomes the high voltage side.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 is a connection diagram of the present embodiment, FIG. 2 is a circuit operation explanatory diagram when the AC power source of the embodiment is a low voltage, and FIG. 3 is a circuit operation explanatory diagram when the AC power source of the embodiment is a high voltage.

In the figure, 1 is an input terminal of an AC power supply having a crest value of 140 V and a low voltage of 100 V, and a crest value of 280 V and a high voltage of 200 V, 2 is a rectifier, 3 is a trigger voltage generating circuit, and 4 is a high voltage short circuit. 5 is a relay circuit, C ₁ is a capacitor for limiting the circuit current of 0.33 μF, ZD ₁ , ZD ₂ , ZD ₃ and ZD ₄ are constant voltage diodes having a breakdown voltage value of 50 V of the trigger voltage generating circuit 3, R is a resistor for generating the trigger voltage of the same circuit, C ₂ is a ripple removing capacitor, LED ₂ is a 200 volt high voltage display light emitting diode, SCR is a thyristor, LED ₁ is a 100 volt low voltage display light emitting diode, RY Is a relay of the relay circuit 5, NO is a low voltage 100 volt side selection terminal, NC is a high voltage 200 volt side selection terminal, and COM is a common terminal.

In this embodiment, the constant voltage diode ZO shown in FIG.₁~ ZO_FourSince the composite breakdown voltage is set to 200 V, which is higher than the peak value of 140 V at 100 V, no current flows at 100 V. Therefore, neither the gate nor the trigger voltage is applied to the gate of the connected thyristor SCR, and the thyristor SCR maintains the OFF state. This is the constant voltage diode ZO₁~ ZO_FourThe thyristor SCR is in the dead zone, and the operating state shown in FIG. Therefore, the coil of the relay RY, the low-voltage display light-emitting diode LED₁Current flows to the relay RY NO contact is closed and low-voltage display LED LED₁Light up (at 100 volts). Also, at 200 V, the constant voltage diode ZO₁~ ZO _Four Has a combined breakdown voltage of 200 V and a peak value of 280 V or less. Therefore, the constant voltage diode ZO₁~ ZO_FourIs turned on and a voltage is applied to the gate of the thyristor SCR to turn on the thyristor SCR. As a result, the high-voltage display light-emitting diode LED is connected between the positive and negative sides of the output DC voltage terminal of the rectifier 2.₂High-voltage display light-emitting diode LED short-circuited via₂Light up, coil of relay RY, light emitting diode LED for low voltage display₁Cut the current flowing through. This is because the coil of the relay RY and the low-voltage display LED LED₁Is regarded as an unnecessary element, and the operation state shown in FIG. 3 is obtained.

As described above, it is not the relay coil but the constant voltage diodes ZO _{1 to} ZO ₄ that operate at 200 V instead of 100 V. Therefore, the contact NO and the current value at 100 V can be matched. The current value when the rectifier 2 is short-circuited is determined by the capacity of the capacitor C ₁ . The set value is kept within the standard of the light emitting diode LED ₂ for high voltage display (10 mA to 20 mA) and 0.33 μF is selected to prevent overcurrent (approx. 20 mA at 200 V. At 60 Hz).

[0011]

[Effect of device]

 As described above, according to the present invention, when the voltage of the AC power source changes, the switch on the voltage side is automatically selected to operate reliably, and the load trouble due to the voltage is eliminated. In addition, since the number of parts can be reduced, it can be manufactured in a small space and at low cost. Furthermore, the efficiency of the relay itself can be improved by adapting the current capacity required by the load and the current capacity of the contacts.

[Brief description of drawings]

FIG. 1 is a connection diagram of the present embodiment.

FIG. 2 is an explanatory diagram of a circuit operation when the AC power source of the embodiment has a low voltage.

FIG. 3 is an explanatory diagram of a circuit operation when the AC power source of the embodiment has a high voltage.

[Explanation of symbols]

1 AC power input terminal 2 Rectifier 3 Trigger voltage generation circuit 4 High voltage short circuit 5 Relay circuit C ₁ Circuit current limiting capacitor ZD ₁ Constant voltage diode ZD ₂ Constant voltage diode ZD ₃ Constant voltage diode ZD ₄ Constant voltage diode R Trigger voltage Resistance for generation C ₂ Capacitor for removing ripple LED ₂ Light emitting diode for high voltage display LED ₁ Light emitting diode for low voltage display SCR Thyristor RY relay

Claims (1)

[Scope of utility model registration request] 1. A trigger voltage generating circuit in which an AC power supply is input to a rectifier and a plurality of constant voltage diodes and resistors having a combined breakdown voltage value intermediate between peak values of different voltages of the AC power supply are connected in series, A high-voltage short circuit in which a thyristor, which uses the voltage between the resistors of the trigger voltage generation circuit as the trigger voltage, and a light-emitting diode for high-voltage display are connected in series, a relay with a relay contact for different voltage selection, and a light-emitting diode for low-voltage display are connected in series. A different voltage automatic selection circuit, characterized in that a relay circuit is connected in parallel between the output DC voltage terminals of the rectifier.