To suppress noise to the surroundings, as well as, to reduce the size and the cost.
The resistor includes a serial resonance circuit 42 for consuming load power; a full-bridge inverter 40 to which an electric power is applied from outside for driving the serial resonance circuit 42; and a control circuit 50 for controlling drive of the full-bridge inverter 40. The control circuit 50 detects the input voltage of the full-bridge inverter 40 by using an input voltage detecting circuit 10, and based on this, adjusts both or one of a drive start detection voltage threshold value for starting drive of the full-bridge inverter 40 based on it and a stop detection voltage threshold for stopping. Thus, an operation start voltage is made different from a stop voltage, and its difference is changed according to circumference, for adjusting the intermittent operation frequency of the serial resonance circuit 42, avoiding operation in audible cycles in which noise is audible.
| JPS57193985 | BRAKING OF CENTRIFUGAL MACHINE |
| JPS6231677 | METHOD OF CONTROLLING SPEED OF DUMB WAITER |
HASHIMOTO TAKASHI
MATSUMOTO SADAYUKI
HARADA SHIGEKI
SUGA IKURO
| JPH0426387A | 1992-01-29 | |||
| JPH0426387A | 1992-01-29 |
Hidetoshi Furukawa
Suzuki Kenchi
Kajinami order
Kazuhiro Oyaku
Shunichi Ueda