Abstract A control circuit for a brushless electric motor includes a pulse width modulator for applying drive signals to a gate drive circuit according to from a current amplifier, multi-phase drive coils connected to the gate drive circuit through an inverter circuit, a comparator connected to the current amplifier, a flip-flop for applying output signals from the comparator and drive signals form the pulse width modulator, and a circuit portion for applying signals for switching the direction of rotation from the flip-flop to the gate drive circuit. A preceding signal for switching the direction of rotation is maintained in the flip-flop until the dead zone of the pulse width modulating circuit is elapsed and a new signal for switching the direction of rotation is generated in synchronism with a pulse signal produced by the pulse width modulating circuit so as to be supplied to the gate drive circuit.
Inventors
👤 Tooru Watanabe
👤 Minoru Shimizu
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-01 00:59
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/30
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
138 words
A control circuit for a brushless electric motor comprising a pulse width modulator for applying drive signals to a gate drive circuit in accordance with signals from a current amplifier, multi-phase drive coils connected to said gate drive circuit through an inverter circuit, a comparator connected to said current amplifier, a flip-flop for receiving output signals from said comparator and drive signals from said pulse width modulator and means for applying signals from said flip-flop to said gate drive circuit for switching the direction of rotation of the brushless motor, wherein a preceding signal is maintained in said flip-flop until a dead zone of said pulse width modulator has passed, whereupon a new signal is generated by said flip-flop in synchronism with a pulse signal produced by said pulse width modulator for application to said gate drive circuit.
Claim 2
Dependent Claim
138 words
A control circuit for a brushless electric motor comprising a pulse width modulator for applying drive signals to a gate drive circuit in accordance with signals from a current amplifier, multi-phase drive coils connected to said gate drive circuit through an inverter circuit, a comparator connected to said current amplifier, a flip-flop for receiving output signals from said comparator and drive signals from said pulse width modulator and means for applying signals from said flip-flop to said gate drive circuit for switching the direction of rotation of the brushless motor, wherein a preceding signal is maintained in said flip-flop until a dead zone of said pulse width modulator has passed, whereupon a new signal is generated by said flip-flop in synchronism with a pulse signal produced by said pulse width modulator for application to said gate drive circuit.
Claim 3
Dependent Claim
14 words
The control circuit according to claim 1 wherein said flip-flop is a D-type flip-flop.
Claim 4
Dependent Claim
15 words
The control circuit according to claim 1 wherein the multi-phase drive coils are three-phase coils.