Switching power supply device
In a switching power supply device, a control circuit controls a first thyristor, a second thyristor, and a switching element according to an input voltage. The control circuit maintains the first thyristor in an on state while maintaining the second thyristor and the switching element in an off state in a first period in which the absolute amplitude value is equal to or less than a first threshold value within the latter half of a first half-cycle of the input voltage at startup, and maintains the second thyristor in an on state while maintaining the first thyristor and the switching element in an off state in a second period in which the absolute amplitude value is equal to or less than a second threshold value within the latter half of a second half-cycle of the input voltage at startup. The second half-cycle is the half-cycle following the first half-cycle.
1. A switching power supply device comprising:
a first switching element connected between a first node and a first output node;
a second switching element connected between the first node and a second output node;
a first thyristor connected between a second input node and the first output node;
a second thyristor connected between the second input node and the second output node;
a detector that detects an input voltage received via a first input node and the second input node; and
a control circuit that controls the first thyristor, the second thyristor, the first switching element, and the second switching element according to the input voltage, wherein
the control circuit maintains the second thyristor and the first switching element in an on state while maintaining the first thyristor and the second switching element in an off state in a first period in which an absolute amplitude value is equal to or less than a first threshold value within a latter half of a first half-cycle in the input voltage at startup, and maintains the first thyristor and the second switching element in an on state while maintaining the second thyristor and the first switching element in an off state in a second period in which an absolute amplitude value is equal to or less than a second threshold value within a latter half of a second half-cycle following the first half-cycle in the input voltage at startup.
2. The switching power supply device according to claim 1 , wherein the control circuit maintains the first thyristor, the second thyristor, the first switching element, and the second switching element in an off state in a third period within the first half-cycle excluding the first period and maintains the first thyristor, the second thyristor, the first switching element, and the second switching element in an off state in a fourth period within the second half-cycle excluding the second period.
3. The switching power supply device according to claim 1 , wherein
the control circuit includes:
a first drive unit that drives the first thyristor;
a second drive unit that drives the second thyristor; and
a drive power supply unit connected to one of the first drive unit and the second drive unit via a diode and connected to the other of the first drive unit and the second drive unit without via a diode.
4. The switching power supply device according to claim 3 , wherein
the control circuit includes:
a signal generation unit;
a first insulation transmission unit that electrically insulates the signal generation unit and the first drive unit and transmits a signal generated by the signal generation unit to the first drive unit; and
a second insulation transmission unit that electrically insulates the signal generation unit and the second drive unit and transmits the signal generated by the signal generation unit to the second drive unit.
5. The switching power supply device according to claim 1 , wherein
the control circuit includes:
a third drive unit that drives the first switching element;
a fourth drive unit that drives the second switching element; and
a drive power supply unit connected to one of the third drive unit and the fourth drive unit via a diode and connected to the other of the third drive unit and the fourth drive unit without via a diode.
6. The switching power supply device according to claim 5 , wherein
the control circuit includes:
a signal generation unit;
a third insulation transmission unit that electrically insulates the signal generation unit and the third drive unit and transmits a signal generated by the signal generation unit to the third drive unit; and
a fourth insulation transmission unit that electrically insulates the signal generation unit and the fourth drive unit and transmits the signal generated by the signal generation unit to the fourth drive unit.
7. The switching power supply device according to claim 5 , wherein
the control circuit includes:
a signal generation unit; and
a third insulation transmission unit that electrically insulates the signal generation unit and the third drive unit and transmits a signal generated by the signal generation unit to the third drive unit, wherein
the signal generation unit and the fourth drive unit are electrically connected to the second output node, and
the fourth drive unit is electrically connected to the signal generation unit, and the signal generated by the signal generation unit is transmitted to the fourth drive unit.
8. The switching power supply device according to claim 1 , further comprising: a noise filter connected between the first input node and the second input node, and the first switching element, the second switching element, the first thyristor, and the second thyristor.
9. A switching power supply device comprising:
a first switching element connected between a first node and a first output node;
a second switching element connected between a second input node and the first output node;
a first thyristor connected between the first node and a second output node;
a second thyristor connected between the second input node and the second output node;
a detector that detects an input voltage received via a first input node and the second input node; and
a control circuit that controls the first thyristor, the second thyristor, the first switching element, and the second switching element according to the input voltage, wherein
the control circuit maintains the second thyristor and the first switching element in an on state while maintaining the first thyristor and the second switching element in an off state in a first period in which an absolute amplitude value is equal to or less than a first threshold value within a latter half of a first half-cycle in the input voltage at startup, and maintains the first thyristor and the second switching element in an on state while maintaining the second thyristor and the first switching element in an off state in a second period in which an absolute amplitude value is equal to or less than a second threshold value larger than the first threshold value within a latter half of a second half-cycle following the first half-cycle in the input voltage at startup.
10. The switching power supply device according to claim 9 , wherein the control circuit maintains the first thyristor, the second thyristor, the first switching element, and the second switching element in an off state in a third period within the first half-cycle excluding the first period and maintains the first thyristor, the second thyristor, the first switching element, and the second switching element in an off state in a fourth period within the second half-cycle excluding the second period.
11. The switching power supply device according to claim 9 , wherein
the control circuit includes:
a first drive unit that drives the first thyristor;
a second drive unit that drives the second thyristor;
a third drive unit that drives the first switching element;
a fourth drive unit that drives the second switching element; and
a drive power supply unit connected to the first drive unit and the third drive unit via a diode, and connected to the second drive unit and the fourth drive unit without via a diode.
12. The switching power supply device according to claim 11 , wherein
the control circuit includes:
a signal generation unit;
a first insulation transmission unit that electrically insulates the signal generation unit and the first drive unit and transmits a signal generated by the signal generation unit to the first drive unit;
a second insulation transmission unit that electrically insulates the signal generation unit and the second drive unit and transmits the signal generated by the signal generation unit to the second drive unit;
a third insulation transmission unit that electrically insulates the signal generation unit and the third drive unit and transmits the signal generated by the signal generation unit to the third drive unit; and
a fourth insulation transmission unit that electrically insulates the signal generation unit and the fourth drive unit and transmits the signal generated by the signal generation unit to the fourth drive unit.
13. The switching power supply device according to claim 11 , wherein
the control circuit includes:
a signal generation unit;
a first insulation transmission unit that electrically insulates the signal generation unit and the first drive unit and transmits a signal generated by the signal generation unit to the first drive unit; and
a third insulation transmission unit that electrically insulates the signal generation unit and the first drive unit and transmits the signal generated by the signal generation unit to the third drive unit, wherein
the signal generation unit and the second drive unit are electrically connected to the second output node,
the second drive unit is electrically connected to the signal generation unit, and the signal generated by the signal generation unit is transmitted to the second drive unit,
the signal generation unit and the fourth drive unit are electrically connected to the second output node, and
the fourth drive unit is electrically connected to the signal generation unit, and the signal generated by the signal generation unit is transmitted to the fourth drive unit.
14. The switching power supply device according to claim 9 , further comprising a noise filter connected between the first input node and the second input node, and the first switching element and the second switching element.
15. A switching power supply device comprising:
first and second input nodes;
first and second output nodes;
an induction element connected to the first input node;
a first switching element connected between the induction element and the first output node;
a second switching element connected between the induction element and the second output node, the first and second switching elements being connected to each other;
a first thyristor connected between the second input node and the first output node;
a second thyristor connected between the second input node and the second output node, the first and second thyristors being connected to each other;
a voltage detector configured to detect an input voltage on the first and second input nodes; and
a control circuit configured to:
set the second thyristor and the first switching element to an on state and the first thyristor and the second switching element to an off state, in a first period in which an absolute amplitude value of the input voltage is equal to or less than a first threshold value; and
set the first thyristor and the second switching element to an on state and the second thyristor and the first switching element to off state in a second period in which an absolute amplitude value of the input voltage is equal to or less than a second threshold value.
16. The switching power supply device according to claim 15 , wherein
the first period is within a first half cycle of the input voltage,
the second period is within a second half cycle of the input voltage, and
the control circuit is configured to:
set the first thyristor, the second thyristor, the first switching element, and the second switching element to an off state in a third period within the first half cycle excluding the first period; and
set the first thyristor, the second thyristor, the first switching element, and the second switching element to an off state in a fourth period within the second half cycle excluding the second period.
17. The switching power supply device according to claim 15 , wherein the control circuit includes:
a first driver configured to drive the first thyristor;
a second driver configured to drive the second thyristor; and
a first drive power supply connected to one of the first driver and the second driver with a diode, and connected to the other of the first driver and the second driver without a diode.
18. The switching power supply device according to claim 17 , wherein the control circuit includes:
a third driver configured to drive the first switching element;
a fourth driver configured to drive the second switching element; and
a second drive power supply connected to one of the third driver and the fourth driver with a diode, and connected to the other of the third driver and the fourth driver without a diode.
19. The switching power supply device according to claim 18 , wherein
the control circuit includes:
a signal generator;
a first insulator transmitter configured to electrically insulate the signal generator and the first driver, and transmit a signal generated by the signal generator to the first driver; and
a second insulation transmitter configured to electrically insulate the signal generator and the second driver, and transmit a signal generated by the signal generator to the second driver.