Abstract: An apparatus for controlling the speed of a combustion blower motor includes first means for generating an output signal representative of a differential pressure. A second means provides a second signal representative of a desired airflow output of the blower and a summation circuit receives the first signal and the second signal and generates a command signal in response thereto. A power output circuit receives the command signal and responsively provides a regulated level of power to the motor for controlling the speed thereof. The first means may be embodied as a diaphragm-type differential pressure transmitter while the second means may be embodied as an adjustable voltage source or as a source which provides an output signal representative of a temperature.

Abstract: A method of controlling a three state apparatus such as an air compressor comprises a first actuating element e.g. a motor and a second actuating element e.g. a valve, said method including the steps of sensing a variable parameter such as temperature with a sensing means whilst the apparatus is operating in a first operational state, feeding a signal produced by the sensing means to a control device, comparing the signal in the control device with datum information to detect whether the variable parameter is at a value at or above a threshold value, sending a signal to the first actuating element when the variable parameter is below the threshold value whereby the state of operation of the apparatus is changed to an off operational state, sending a signal to the second actuating element when the variable parameter is at a value at or above the threshold value whereby the state of operation of the apparatus is changed to a low load operational state.

Abstract: A variable pneumatic output device for use with ophthmalic micro-surgical instruments including a reversible servo motor which operates in response to instructions from an electronic control circuit. The rotatable drive shaft of the servo motor is operatively connected to the adjustable level control of a precision pressure regulator which operates between a fully open level and a fully closed level. The pressure regulator is operatively connected between a pressurized air source and the pneumatically driven micro-surgical instrument and according to the instructions of the electronic control circuitry, the servo motor, through the connecting drive to the regulator, adjusts the level of pneumatic output to the surgical instrument.

Abstract: An adjustable automatically controlled pneumatic pump device includes an air pump, an electric motor adapted for being energized by a power source to drive the air pump, an air hose member with an exhaust port at one end, and an other end of the hose member connected to the air pump, a pressure gauge with a pressure setting pointer which can be adjusted in advance according to the predetermined air pressure desired and a pressure indicating pointer which is capable of contacting with the pressure setting pointer when the air pressure through the air hose reaches the predetermined air pressure, and an electric logic circuit device which is electrically associated with the motor and the pressure gauge and arranged in that the electric logic circuit can control the motor for pumping air into an enclosed space.

Abstract: A pressure control apparatus, which can be used for a braking force magnification apparatus for a vehicle or a door closing and opening apparatus includes a sensor for sensing a pressure within a vacuum booster. The sensor is of a transfer-contact-type including a medial movable contact and two stationary contacts. The movable contact makes contact with one of the stationary contacts connected to an alarm lamp but breaks contact with the other connected through a control circuit to a DC motor connected to a vacuum pump or a compressor when the absolute gauge pressure produced by the vacuum pump or compressor is below a first predetermined threshold value. The movable contact breaks contact with the one stationary contact to energize the DC motor when the absolute gauge pressure is below a second predetermined threshold value but is above the first one.

Abstract: A resistive network is used for an electro-pneumatic converter so that the speed of the electro-pneumatic converter can be regulated. The converter includes a reversible DC servo motor having a pair of terminals connected to a pair of lines. The lines are selectively connectable to a common terminal of a power supply. The power terminal of the power supply is connected over a variable resistor to a terminal connecting the lines. Selectively connecting one of the lines to the common terminal causes electrical power to pass through the motor and one for an opposite direction to turn the motor shaft in a selected direction of rotation. The speed of rotation is determined by the position of the variable resistor. The motor shaft is used in conjunction with a cam that is associated with a nozzle supplied with pressurized gas over a bellows. The nozzle is moved closer or further away from the cam edge as the bellows expands or contracts.

Abstract: Disclosed is a control for a pumping device in vehicle application in which, upon throwing a power switch (6) and closing a brake actuator switch (8), a second driver transistor (76) is rendered conductive and a first driver transistor (75) non-conductive, thereby rendering a power transistor (71) conductive. The power transistor in the conductive state enables a DC motor (2) to be supplied with a DC voltage from batteries (5). The DC motor drives a pump (1) which in turn feeds a pressure to activate a pressure-operating unit (10). A pressure detecting switch (4) detects the pressure of the pump and particularly provides a pressure detection signal when the pressure reaches a predetermined value. In response to the pressure detection signal the first driver transistor becomes non-conductive and the power transistor becomes conductive, thus supplying the DC voltage to the DC motor.

Abstract: Disclosed is a control for a pumping device in a vehicle application in which, upon throwing a power switch (6), a capacitor (85) is charged and a power transistor (81) is rendered conductive thereby supplying a DC voltage from batteries (5) to a DC motor (2). The DC motor drives a pump (1) which in turn feeds pressure to a pressure-operating unit (10) for storage therein. If a given period of time has elapsed after throwing of the power switch, then the voltage charged on the capacitor increases to make a transistor (83) conductive and the power transistor (81) non-conductive. In other words, the DC motor is operated to provide pressure to the pressure-operating unit for only the given period of time after throwing of the power switch. Furthermore, upon closure of a brake actuator switch (4) another transistor (84) becomes conductive and the above transistor (83) becomes non-conductive. This renders the power transistor (81) conductive and supplies the DC voltage to the DC motor.

Abstract: Disclosed is a control for pumping devices in vehicle application. Upon closure of a brake actuator switch (4) subsequent to actuation of a power switch (6) a power transistor (81) becomes conductive and a DC voltage from batteries (5) is fed to a DC motor (2). The brake actuator switch when brought into an open position permits supply of the DC voltage to the base of the power transistor through a time constant circuit (85, 86) for a limited period of time, so that the power transistor becomes conductive to supply the DC voltage to the DC motor for that period. The DC motor activates a pump (1) which in turn operates a pressure-operating unit (10).

Abstract: A control device for a vacuum pump apparatus in which a hunting effect is substantially eliminated. A pressure-sensitive switch senses a negative pressure produced by a vacuum pump, the latter being driven by a d.c. motor. The switch has at least three contacts, the positions of which are changed at two different pressures. The output of the switch is compared with a fixed reference value, and the comparison result used to drive the d.c. motor. The d.c. motor is thus provided with hysteretic drive characteristic, thereby maintaining the vacuum pressure between the two predetermined values and eliminating the hunting effect.

Abstract: An automatic system for controlling a plurality of motors includes motor starting circuitry and motor stopping circuitry that serves to sequentially start and stop the motors in the same cyclic order. The starting circuitry has a sensing component for sensing the presence and absence of a condition that reflects the need for starting the motor and a master starting control component which develops two different states that are used in controlling the circuits of the starting circuitry. The control circuits include a plurality of motor starting circuits for starting the respective motors and a plurality of conditioning circuits that normally respond to one of the developed states for conditioning the starting circuits for response sequentially to the other of the developed states and in a cyclic order for starting the motors.

Abstract: Device to control the speed of an electric motor from a pneumatic pedal, characterized in that it includes an element deformable with the pressure controlled by the pneumatic pedal, an element of magnetic material forming a mechanical unit with the element deformable with the pressure and capable of modifying the inductance of a coil incorporated into an electronic control circuit for the current of the electric motor the speed of which is to be controlled.

Abstract: An electrical control arrangement which includes firstly an electronic transducer, which is adapted to receive a controlled stream of fluid, and secondly control means to be controlled by the electronic transducer to control the speed of a micro-motor in a linear manner.

Abstract: A control system for a compressor driven by a pole-changing motor comprises a pole changer for the motor, a contactor for stopping the motor for a predetermined time in case of the pole changing, and a switch responsive to the variation in a physical quantity which occurs in the compressor every time when the latter is stopped, whereby the motor is stopped in case of the pole changing and then is started again in response to the actuation of the switch. This control system is especially adapted for use in a pole-changing-motor-driven compressor used in a refrigeration cycle of an air conditioner.

Abstract: A hydraulic circuit for operator pre-selection in one exemplary embodiment of the extension of a lift truck upright which utilizes a fixed displacement hydraulic motor operating to adjust either a rotary switch or a potentiometer which is connected to a valve for interrupting the flow to the lift cylinder of the upright at the pre-selected height. The adjusted position of an operator's lift height selector is coordinated with the rotary switch or potentiometer or to effect the selected extension of the upright.

Abstract: A control circuit for a motor usable in a refrigeration system has a variety of condition sensors including means to sense a low refrigerant pressure and timing means to override the sensing of low refrigerant pressure for a time period during motor start-up. A lockout circuit prevents re-start of the motor following a fault condition.

Abstract: A motor protection circuit includes a capacitance and resistance timing circuit together with temperature sensing facilities which are energized upon motor startup to terminate operation of a motor in the event of insufficient oil pressure or excessive heat. An oil pressure sensing switch is connected to the timing circuit to prevent its operation so long as sufficient oil pressure is sensed.

Abstract: A control circuit for a motor has an electronic RC timing circuit with a fluid pressure switch for shunting the timing circuit if the fluid pressure reaches and maintains a predetermined magnitude. The timing circuit terminates the energization of the motor when not shunted for a predetermined duration.

Abstract: A motor protection circuit employs a resistance bridge circuit with one side having multiple branches containing temperature responsive resistances for sensing an overheat condition in the motor. Semiconductor voltage sensing devices, such as high gain amplifiers, are responsive to voltages between a standard sensing node and each of the sensing nodes in the multiple branched side of the bridge circuit. Logic facilities respond to any of the sensing devices to operate switching facilities controlling energization of the motor. Additionally, the protection circuit may include a lubricating oil pressure responsive control which is not affected by power loss or spurious signals, and which may be controlled by the operation of a motor control switch.

Abstract: A control system for a motor having a required oil pressure for the safe operation thereof, the system having a time delay switch for interconnecting an electrical source to the motor to operate the same each time the time delay switch is initially activated by being placed across the power source. The time delay switch has a time delay bimetal means that is adapted to move and open the switch if the oil pressure of the motor does not reach the required value within a predetermined time period from the initial activation of the time delay switch. An oil pressure responsive switch is operatively interconnected to the time delay bimetal means and to the motor to terminate the switch opening movement of the time delay bimetal means if the oil pressure reaches the predetermined value thereof during the predetermined time period so that the motor will be continuously operated as long as the system is not manually or automatically turned off or the oil pressure does not fall below the predetermined value thereof.