Abstract: This is a command device for a vehicle seat, including electric motors connected to a common power supply, position sensors associated with these motors, an electronic central unit and a motor command keypad which includes power-on/power-off switches connected to the common power supply via a single relay. When the central unit receives the order to look for a seat position stored in memory, it monitors the actuation of the power-on/power-off switches and opens the relay when it detects such an actuation which would tend to move the seat away from said memorized position.

Abstract: A motor start-up circuit is incorporated in a motor-driving circuit provided with an auxiliary coil which operates during a start-up time of the motor and a main coil for a steady-state operation of the motor. The start-up circuit in one form has a start-up thermistor with positive temperature characteristic and a Triac switch connected in series with the auxiliary coil and a triac-controlling thermistor with positive temperature characteristic connected in parallel to the start-up thermistor, and one of the terminals of the triac-controlling thermistor is connected to the gate of the Triac switch. The start-up circuit in another form has a Triac switch connected in series with the auxiliary coil and a triac-controlling thermistor with positive temperature characteristic connected in parallel to the auxiliary coil and the Triac switch and one of the terminals of the triac-controlling thermistor is connected to the gate of the Triac switch.

Abstract: A dc motor speed control circuit is provided. A first circuit utilizing an opto-electric sensor for providing an input signal corresponding to a desired dc motor speed is connected to a second circuit and the second circuit is connected to the dc motor, wherein the second circuit responds to the input signal and causes current to flow through the dc motor corresponding to the input signal. A temperature circuit, voltage level circuit and current level circuit may also be connected to the second circuit to control the dc motor.

Abstract: Electronic circuits and methods are disclosed for remote control of a locomotive in a model railroad layout having an interruptible DC power supply coupled to the railroad track. The locomotive motor is isolated from the track so as to allow use of polarity reversals on the track power signal for controlling remote effects in the locomotive such as sound and visual effects. An on-board electronic state generator is provided in the locomotive for maintaining one at a time of a predetermined set of states, at least one of the states having a corresponding remote effect associated therewith. Remote control signals such as a pulsed reversal in polarity of the DC track power signal (PRP) or high voltage pulse (HVP) are used to clock the state generator to a desired state, thereby permitting control of a plurality of remote effects using only the traditional DC power supply interface.

Abstract: It comprises a mechanical power input (1, 55) receiving the power preferably from an electric motor and a mechanical power output (3, 67), as well as transfer means (2, 2', 2", 2'", 4, 64) for transferring this power from the input to the output, and control means (2, 5, 6, 7, 59, 60, 61) for controlling the transfer means (2, 4, 64) to make sure that the power transferred at the output does not exceed a predetermined level. There are provided means to break down the power received at the input into a power applied at the output (3, 67) and excess power which is used to produce the cut-off of power supplied by the motor. This excess power is controlled by the pressure of element (6, 7, 61) whose tension is adjustable which actuates against a movable surface which defines a cam profile, thereby increasing the force or torque during the angular or linear motion of the cam (2, 2', 2", 2'"). The transfer mechanism includes a basic group with four different output alternatives (C1, C2, C3 and C4).

Abstract: An on/off switching component of a motor powered according to a first or a second polarity, connected in series with the motor. The switching component includes two head-to-tail connected cathode gate thyristors, and two diodes of same polarity. The two diodes have first same polarity terminals respectively connected to the gate of a respective one of the two cathode gate thyristors and second terminals connected together to a control terminal.

Abstract: A stepping motor control system for a recording apparatus which uses a stepping motor as a driving source of a carriage with a recording head, has a stepping motor driving circuit for exciting the phases of the stepping motor, and a control circuit for transferring data corresponding to a predetermined stepping motor driving curve to the driving circuit, so as to easily obtain a stepping motor driving curve that can suppress vibrations, and the driving curve is formed from an Nth-order specific formula having two or more inflection points.

Abstract: A motor-winding driver circuit includes a high-side double-diffused metal-oxide-semiconductor (DMOS) field-effect transistor (FET) connected between a direct-current (DC) power supply node and a driver output node, and a low-side DMOS FET connected between the driver output node and ground. A high-side drive circuit and a low-side drive circuit regulate the driver output voltage to prevent a parasitic bipolar PNP transistor in the high-side FET from conducting, so that latchup is avoided. A parasitic N+/P-substrate diode in the low-side FET is also prevented from conducting. The low-side and high-side driver circuits have additional circuitry causing them to act as active clamp circuits during extreme over- or under-voltage conditions. A body-switching circuit connects the body of the high-side DMOS FET to the driver output node during normal operation, and connects the body to the DC supply node when the driver output voltage exceeds the DC source voltage.

Abstract: A control circuit and method for controlling a sensorless brushless DC motor are provided which are capable of effectively filtering noise. The control circuit includes: a phase voltage measuring unit for determining the voltage of each phase from the terminal voltages of the stator coils; a phase voltage sign detecting unit for detecting the sign of the phase voltage measured from the phase voltage measuring unit and outputting a phase voltage sign signal; and a digital phase-shifter for generating a delay signal which is delayed up to 90.degree. with respect to the phase voltage sign signal and supplying the delayed signal to the commutation unit.

Abstract: A mechanism for stopping an object to be swung in a predetermined stop position and holding the object in that position includes a temporary stopping unit for stopping the swing of the object in a temporary stop position before the stop position, a rotation complementing unit for complementarily further rotating the object from the temporary stop position to the stop position, and a holding unit for holding the object in the stop position.

Abstract: An apparatus and method for soft-starting a three-phase motor for connection to a three-phase power source for driving a three-phase motor. Soft-start provides a way to reduce the amount of starting torque and current during starting conditions. First, second, and third conductors are connected between a three-phase power source and a three-phase motor. A power contactor interrupts and provides current along the three conductors. A phase-shifting element for shifting the phase of the power signal normally outputted from the first conductor to match the phase of the power signal normally outputted from the third conductor is connected between the first and third conductors. A switching apparatus having first and second switch elements is connected between the phase-shifting element and the third conductor. When the first switch element is closed, current flows from the first conductor to the motor via the phase-shifting element.

Abstract: A servomechanism is controlled to move at a rate below a critical limit by means of a feedback controller (10) which is responsive to the output of a rate measurement device (9). The feedback controller (10) has a non-linear response whose effect only becomes appreciable when the measured rates approach the critical limit. Operation within the critical limits ensures stable and accurate operation of the servomechanism.

Abstract: An actuator controller capable of preventing various inconveniences that stem when the operation positions of the actuator have not been learned.

Abstract: A motor control system provides a low-cost method of phase-locking a motor to an input timing signal. Timer circuits 502, 506 measure the period of a timing signal and the relative phase between the timing signal and a motor rotor. A frequency command generator circuit 520 outputs a motor speed command based on the period of the timing signal and the relative phase of the timing signal compared to the motor rotor. The motor speed command controls the output of a motor driver circuit which drives the motor rotor speed synchronously with the input timing signal. The rotor speed is gradually altered to adjust the relative phase between the input timing signal and the motor rotor. This results in a small frequency-lock error being used to maintain a predetermined phase relationship between the timing signal and the motor rotor.

Abstract: A variable-speed control apparatus computes the leakage inductance of an AC motor, correctly compensates the leakage inductance, and controls the variable speed of the AC motor. The variable-speed control apparatus has an AC signal generation circuit for generating an AC signal, and obtains a leakage inductance calculation value of the AC motor based on the AC signal and the measured actual current value. The differential value of the summation of a current command value and the AC signal is multiplied by the leakage inductance calculation value to generate a signal for use in compensating the voltage drop caused by the leakage inductance, and added to a voltage command value to cancel the deviation between the actual current value and the M-axis current command value and to obtain the second voltage command value. The second voltage command value is converted into a 3-phase voltage command value and used in controlling the AC motor, and the voltage drop caused by the leakage inductance can be compensated.

Abstract: In a controller for an electric vehicle, a voltage current phase difference calculating circuit calculates a vector phase .theta..sub.c from a voltage command value and the primary current of an alternating current motor. The vector phase .theta..sub.c is input to a second voltage command circuit which calculates a second d-axis voltage command value and a second q-axis voltage command value using the vector phase .theta..sub.c and d-axis and q-axis current differences. By correcting the voltage command value using the second d-axis and second q-axis voltage command values, the stability of the current control system is improved. By controlling the electric vehicle using such a system, a stable current control can be attained even when the electric vehicle is driven under a regenerative running state or a weak magnetic field control state.

Abstract: In an electric vehicle having a synchronous motor as the driving source, a control system and a control method for the electric vehicle can prevent over current in the main circuit or over charging of the battery at the re-closing of an opened inverter relay and is always capable of operating the power-train system in a better condition. A control method for an electric vehicle having an inverter for supplying a direct current electric power from a battery to the synchronous motor, a smoothing capacitor, connected to the inverter in parallel for smoothing the direct current electric power, an inverter control circuit and an inverter relay for connecting and disconnecting the inverter and the smoothing capacitor to and from the battery. The inverter is controlled so as to prevent current from flowing into or flowing out of the inverter until the re-closing operation of the inverter relay is completed when the opened inverter relay is re-closed.

Abstract: An adjustable sound enhancing muffler device for a percussion instrument includes a first arm member having structure to be connected to a percussion instrument which is cooperative with a second arm member having a plurality of pad members having sound-muffling characteristics. The second arm member is selectively and removably connected to the first arm member at a point adjacent a slot of the first arm member to provide for a variety of radial and axial positioning of the second arm member with respect to the first arm member. The plurality of pad members may be maintained in a constant set contact with a membrane of a percussion instrument at a selected tension by means of a threaded screw cooperating with a tension spring.

Abstract: A brushless motor driving device includes a comparator. The comparator compares a control voltage with a control signal in proportion to a control current of each Hall element. An output of the comparator is amplified by a Hall element driving amplifier, and is inputted to a control current terminal of each Hall element as an error signal. Each Hall element outputs a Hall signal based on an inputted error signal. The driving voltage is controlled such that an amplified Hall signal matches with a driving voltage applied to each driving coil. The brushless motor driving device permits a brushless motor to be stably driven at any rotation speed from low-speed rotations till high-speed rotations with a simple circuit structure.

Abstract: A commutation circuit for a switched reluctance electric motor. Each phase coil in the motor discharges through a resistance. The resistance is progressively increased during discharge, to thereby decrease the overall time required for full discharge. This decrease in discharge time allows each phase coil to pass current for a longer time, thereby increasing torque which the motor produces.