Patent
Speed control for a universal electric motor
TLDR
In this article, the phase angle during which current flows through the motor in the negative halfwave of the voltage supply is determined by a first thyristor, under control of a speed setting provided in an RC circuit.Abstract:
A first thyristor, under control of a speed setting provided in an RC circuit varies the phase duration of current supply to the motor during positive halfwaves of the a c supply, and a second thyristor controlled in accordance with the motor current provided through the first thyristor determines the phase angle during which current flows through the motor in the negative halfwave of the voltage supply, so as to maintain the speed at the set value under varying conditions of load. During positive halfwaves, a capacitor is charged to a voltage corresponding to the amount of current flow through the motor and during the following negative halfwave, the charge is increased at a rate set by an RC circuit, resulting in turning on the second thyristor early under heavy load conditions, and late under light load conditions, and indeed not at all under idling conditions.read more
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Patent
Microcomputer controlled power tool
John Maruscak,David Alan Saar +1 more
TL;DR: In this article, a microcomputer controlled power tool (10) including a semiconductor control device (64) connected to the motor (66), one or more sensors (36, 58), and a micro computer (50) interfaced to a keyboard (28) and digital display (30) for monitoring and controlling various operating conditions and parameters of the power tool is described.
Patent
System for controlling the rotation of AC motors
Andras Lelkes,Jens Krotsch +1 more
TL;DR: In this article, a controllable electronic switching device is connected upstream of the motor and is actuated by a control unit such that a sinusoidal input AC voltage is used to produce a motor AC voltage which can be varied in order to change the rotation speed.
Patent
System for speed control of AC motor
Jens Krotsch,Andras Lelkes +1 more
TL;DR: In this article, an electronically controlled switch is connected before the motor that is driven by a control unit so that a variable AC motor voltage (UM) is produced from a sinusoidal input AC voltage (UN) to vary the revolution rate.
Patent
Rotating electric motor for operating an electric component
TL;DR: In this article, a rotating electric motor for operating an electric component is described, and an electric drive circuit is arranged for the winding of the motor, which exhibits at least one branch including an electric energy bank and a thyristor.
Patent
Stationary machine tool, in particular circular sawing machine or milling machine
TL;DR: The rotational speed adjuster can be a potentiometer or electronic current adjuster as discussed by the authors, which can also be used to control the load of the motor and the no-load speed.
References
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Patent
Stabilizing phase controlled ac induction motors
TL;DR: In this article, an adjustable speed capacitor run or polyphase AC induction motor is stabilized by an AC phase control circuit whose timing is referenced to the zero crossing of the capacitor voltage in an RC circuit and supplies gating signals to a thyristor in series with the motor.