Electric positioning motor control system, particularly automatic vehicle antenna extension system
First Claim
1. Electrical positioning motor control system for automatically de-energizing a commutator-type d-c motor (12) coupled to a positioned element (13) when the positioned element has reached a predetermined position, said system havingan operator-controlled switch (24, 27) for controlling energization of the motor;
- motor direction-of-operation control switch means (R1, r1, R2, r2) selectively energizing the motor for rotation in either of two directions, or for de-energizing the motor;
a control circuit (30) having at least one control input (21) coupled to the operator-controlled switch and first and second outputs (31,
32) coupled to control the motor direction switch means (R1, r1, R2, r2), said system comprising, in accordance with the invention,a measuring means (18,33) coupled to a connection line (X) of the motor (12), sensing the rotary speed of operation of the motor, when energized, and including analyzing means (33,33'"'"') responsive to a time characteristic of the waviness of undulation of motor current in said connection line to produce a motor operation speed signal;
a motor operation input (34) on said control circuit (30) and receiving the motor speed signal;
a memory (M) in said control circuit (30) storing a representation of the average value of said time characteristic; and
a speed-signal-responsive circuit (S) in said control circuit (30), connected to and controlling the electrical energy supplied to the motor and disconnecting said energy supply thereto upon sensing drop-off of speed of operation of the motor below a predetermined limit, regardless of the position of the operator-controlled switch means (24).
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Accused Products
Abstract
A commutator-type d-c motor has its line current connected through a sensing resistor (18) or transformer (18'"'"'), the pulses of which, upon energization, are counted in a counter (C) and also passed to a speed sensing circuit (S) in a control circuit (30), energization of the motor being disconnected if the frequency of undulations or waviness of the motor current drops, thus indicating that the positioned element, for example an antenna, window, or sliding roof of an automobile has reached a limiting position. The counter can be used to establish intermediate positions, upon suitable control by a selector switch (27) or a reference count number stage (C-Ref) controlled, for example, by a potentiometer (P) or from the selector switch (27). A timing circuit (T) prevents short-circuit through the motor upon manual sudden reversal of command of direction of rotation. The main switch can be coupled to a car radio to extend the car radio antenna upon energization thereof, retract the antenna upon de-energization, the selector switch also permitting manual retraction or projection, and disabling of the system if, for example, the radio is used for stored, e.g. tape reproduction.
81 Citations
26 Claims
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1. Electrical positioning motor control system for automatically de-energizing a commutator-type d-c motor (12) coupled to a positioned element (13) when the positioned element has reached a predetermined position, said system having
an operator-controlled switch (24, 27) for controlling energization of the motor; -
motor direction-of-operation control switch means (R1, r1, R2, r2) selectively energizing the motor for rotation in either of two directions, or for de-energizing the motor; a control circuit (30) having at least one control input (21) coupled to the operator-controlled switch and first and second outputs (31,
32) coupled to control the motor direction switch means (R1, r1, R2, r2), said system comprising, in accordance with the invention,a measuring means (18,33) coupled to a connection line (X) of the motor (12), sensing the rotary speed of operation of the motor, when energized, and including analyzing means (33,33'"'"') responsive to a time characteristic of the waviness of undulation of motor current in said connection line to produce a motor operation speed signal; a motor operation input (34) on said control circuit (30) and receiving the motor speed signal; a memory (M) in said control circuit (30) storing a representation of the average value of said time characteristic; and a speed-signal-responsive circuit (S) in said control circuit (30), connected to and controlling the electrical energy supplied to the motor and disconnecting said energy supply thereto upon sensing drop-off of speed of operation of the motor below a predetermined limit, regardless of the position of the operator-controlled switch means (24). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification