Electric working machine and voltage supplier
A voltage supplier in one aspect of the present disclosure includes a first voltage generator, a second voltage generator, a first switcher, a second switcher, a first booster, and a second booster. The first booster boosts a voltage lower than a first switching drive voltage to thereby generate the first switching drive voltage, and supplies the first switching drive voltage to the first switcher on a first supply path. The second booster boosts a voltage lower than a second switching drive voltage to thereby generate the second switching drive voltage, and supplies the second switching drive voltage to the second switcher on a second supply path.
1. A blower comprising:
a fan;
a motor configured to drive the fan;
a motor driving circuit configured to drive the motor;
a first supply path configured to supply a first power supply voltage from a positive electrode of a first battery pack to the motor driving circuit;
a first booster circuit configured to:
obtain the first power supply voltage from the first supply path; and
boost the first power supply voltage to generate a first boosted voltage;
a first battery switching circuit including a first N-channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) disposed on the first supply path, the first N-channel MOSFET including:
a first drain coupled to the positive electrode of the first battery pack;
a first source coupled to the motor driving circuit; and
a first gate coupled to a first logical circuit that is configured to turn on the first N-channel MOSFET by supplying the first boosted voltage to the first gate based on two or more signals input to the first logical circuit;
a second supply path configured to supply a second power supply voltage from a positive electrode of a second battery pack to the motor driving circuit;
a second booster circuit configured to:
obtain the second power supply voltage from the second supply path; and
boost the second power supply voltage to generate a second boosted voltage; and
a second battery switching circuit including a second N-channel MOSFET disposed on the second supply path, the second N-channel MOSFET including:
a second drain coupled to the positive electrode of the second battery pack;
a second source coupled to the motor driving circuit; and
a second gate coupled to a second logical circuit that is configured to turn on the second N-channel MOSFET by supplying the second boosted voltage to the second gate based on two or more signals input to the second logical circuit.
2. An electric working machine comprising:
a motor;
a motor driving circuit configured to drive the motor;
a first supply path configured to supply a first power supply voltage from a positive electrode of a first battery pack to the motor driving circuit;
a first booster circuit configured to:
obtain the first power supply voltage from the first supply path; and
boost the first power supply voltage to generate a first boosted voltage;
a first battery switching circuit including a first switching device disposed on the first supply path, the first switching device including:
a first terminal coupled to the first battery pack; and
a second terminal coupled to the motor driving circuit, the first switching device being configured to electrically couple the positive electrode of the first battery pack to the motor driving circuit in response to the first switching device being turned ON, and the first battery switching circuit being configured to turn on the first switching device with the first boosted voltage in response to a first condition being established;
a second supply path configured to supply a second power supply voltage from a positive electrode of a second battery pack to the motor driving circuit;
a second booster circuit configured to:
obtain the second power supply voltage from the second supply path; and
boost the second power supply voltage to generate a second boosted voltage;
a second battery switching circuit including a second switching device disposed on the second supply path, the second switching device including:
a first terminal coupled to the second battery pack; and
a second terminal coupled to the motor driving circuit, the second switching device being configured to electrically couple the positive electrode of the second battery pack to the motor driving circuit in response to the second switching device being turned ON, and the second battery switching circuit being configured to turn on the second switching device with the second boosted voltage in response to a second condition being established; and
a first charge inhibition circuit configured to electrically interrupt the first terminal of the first switching device from the positive electrode of the first battery pack in response to a voltage at the first terminal of the first switching device being larger than a voltage at the positive electrode of the first battery pack.
3. The electric working machine according to claim 2 , wherein the first condition is established in response to the following (i) to (iii) being satisfied:
(i) the first battery pack is normal;
(ii) an electric discharge from the first battery pack is permitted; and
(iii) there is no failure in the first battery switching circuit and the first charge inhibition circuit.
4. The electric working machine according to claim 2 , further comprising
a second charge inhibition circuit configured to electrically interrupt the first terminal of the second switching device from the positive electrode of the second battery pack in response to a voltage at the first terminal of the second switching device being larger than a voltage at the positive electrode of the second battery pack.
5. The electric working machine according to claim 4 , wherein the second condition is established in response to the following (i) to (iii) being satisfied:
(i) the second battery pack is normal;
(ii) an electric discharge from the second battery pack is permitted; and
(iii) there is no failure in the second battery switching circuit and the second charge inhibition circuit.
6. The electric working machine according to claim 2 , wherein the second terminal of the second switching device is electrically coupled to the second terminal of the first switching device.
7. The electric working machine according to claim 2 , wherein the first switching device and/or the second switching device comprises an N-channel MOSFET.
8. The electric working machine according to claim 2 , wherein the first switching device and/or the second switching device comprises an insulated gate bipolar transistor (IGBT).