GB2154383A

GB2154383A - Motor control system

Info

Publication number: GB2154383A
Application number: GB08503839A
Authority: GB
Inventors: Alan Reginald Palmer; Mark Palmer
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-02-15
Filing date: 1985-02-14
Publication date: 1985-09-04
Also published as: GB2154383B; GB8503839D0; GB8403914D0

Abstract

A motor control system, in particular for the drive motors 19, 20, 21 of a plurality of motorised valves for an agricultural sprayer, are connected to a power supply by way of a switching system which enables all the motors to be switched on or off simultaneously by a main control or allowing only particular motors to be energized. <IMAGE>

Description

SPECIFICATION Motor control system This invention relates to a motor control system. It is particularly concerned with a control system enabling valves to be readily motored between working positions individually or in groups.

According to the present invention there is provided a motor control system for a plurality of electric motors connected in parallel characterised by a first rail (14) of a power supply (10) for each motor (11, 12, 13) being connectable to a first polarity of power supply (10); a second rail (15) being connectable to the other or another polarity of power supply by way of a switching arrangement (23, 23A, 23B, 37, 41) such that in the first position of the arrangement the second rail (15) is connected to all the motors (11, 12, 13) and in the second position of the arrangement the second rail (15) is only connected to a given motor if an independent switch (24/25, 24A/25A, 24B/25B) for a motor (11, 12, 13) is in an operation-enabling-position for that motor.

In a preferred form of the present invention the switching arrangement is characterised by: (A) each motor (12) having a first switch (25) with an output (7) coupled to the motor (12) and first (8) and second (9) inputs; and a second switch (24) having an input (28) coupled to a first line (31) by a diode (32), and first (29) and second (30) outputs; the first input (8) of the first switch (25) being coupled by one channel (26) to a first output (29) of the second switch (24); the second input (9) of the first switch (25) being coupled by another channel (27) to the second output (30) of the second switch (24); the one channel (26) being connected to a second line (33) by a diode (34); the other channel (27) being connected to a third line (35) by a diode (36); the first (25) and second (24) switches being ganged to ensure that in a given position they are coupled to a common channel (26, 27); and (B) switching comprising a master switch (37) whereby the second (33) or third line (35) can be coupled to a first output (43) of a changeover switch (41), a second output (45) of the changeover switch (41) being coupled to the first line (31), an input (42) to the changeover switch (41) being coupled to the second rail (15); the changeover switch (41) being operable to connect one or other output (43, 45) to the input (42).

An exemplary embodiment of the invention will now be described with reference to the accompanying drawing of which the sole figure is a circuit diagram of switchgear for a mobile agricultural spraying system.

The spraying system is made up of a series of articulated spray booms mounted on a trailer which also serves to carry a tank of liquid material for spraying through the booms. The booms are coupled to the tank by way of pipework incorporating a sequence of motorised valves and a pump. Each valve can be switched as required to enable liquid from the tank either to be sprayed through the portion of the boom the valve regulates or restore pressurised liquid to the tank by way of a return line. Switches to operate each valve are mounted adjacent the working position of the sprayer operator. Typically the trailer is towed by a tractor whose driver operates the switches in dependence on the number of booms which are to be used to spray in a given spray pass.

Referring now to the Drawing electric motors 11, 12, 1 3 each serve to power one of the valves regulating flow into a boom of the sprayer. Rail 14 serves to couple the motors 11 - 13 to battery 10 by way of, respectively, brushes 16, 17, 18.

Rail 1 5 couples battery 10 to brushes 19, 20, 21 through a switching system which includes a sequence of branches 23, 23A, 23B together with master switch 37 and changeover switch 41.

Since each branch is made up of components which are similar in form and function only the components of branch 23 (for motor 12) will be described in detail. Corresponding items for the other branches are given similar reference numerals to those in branch 23 with the addition of a suffix A for branch 23A (for motor 11) and suffix B for branch 23B (for motor 13).

Branch 23 comprises ganged switches 24/25 joined by channels 26, 27. The switch 24 serves to link contact 28 with one or other of contacts 29, 30.

Contact 28 is coupled to first line 31 by way of diode 32. In addition to first line 31 acting as a supply rail to diode 32 it also supplies diodes 32A and 32B.

Contact 29 is coupled to second line 33 by way of diode 34. In addition to second line 33 acting as a supply rail to diode 34 it also supplies diodes 34A and 34B.

Contact 30 is coupled to third line 35 by way of diode 36. In addition to third line 35 acting as a supply rail to diode 36 it also supplies diodes 36A and 36B.

Master switch 37 enables contact 38 to be connected either to third line 35 by way of contact 39 or to second line 33 by way of contact 40.

Changeover switch 41 serves to couple contact 42 (to which rail 1 5 is connected) to either contact 43, as shown, which is connected to contact 38 by line 44; or to contact 45. Contact 45 is connected to first line 31.

The switch pairs 24/25, 24A/25A and 24B/25B are each operated by a single control. These three controls, together with master switch 37 and changeover switch 41, are mounted on a single panel which is positioned adjacent a control position for the sprayer.

In operation, with the switches positioned as shown, power is fed between rails 14 and 15 by way of the switches 41 and 37 to the third line 35. First line 31 and second line 33 are effectively maintained isolated. The supply on third line 35 results in all three motors 11, 12, 1 3 being energised so allowing pressurised liquid from the tank to pass to each section of boom regulated by the valves.

In this case operation of any of switch pairs 24/25, 24A/25A or 24B/25B to the opposite position to that shown in the Drawing will cause the valve governed by the motor to cease passing pressurised liquid to the boom and instead divert liquid back to the supply tank.

Operation of the switch 37 from the position shown to join contacts 38 and 40 will rsult in power supply to the motors being removed from all the motors regardless of the position of the switch pairs.

With the switches initially in the position shown subsequent operation of changeover switch 41 to link contacts 42 and 45 will isolate third line 35 and supply power to first line 31. In this event all the motors will continue energised. This situation will obtain regardless of the position of any of the switch pairs. In the case of branch 23, for example, power will be fed from the first line 31 to contact 28 and so to whichever of lines 26, 27 are connected by way of switch pair 24/25.

In the event that all the switch pairs are positioned in the opposite sense to that shown in the Drawing and master switch 37 and changeover switch 41 are positioned as shown then none of the motors will be energised since only third line 35 is connected to rail 1 5 and the third line is isolated from all other motors. Operation of changeover switch 41 in this situation will result in power being fed to first line 31 with consequent energisation of all motors.

It will be apparent that the addition of master switch 37 and changeover switch 41 to the switching provided by the switch pairs enables the sprayer to be more readily regulated than would be possible by means of the switch pairs alone. In particular the specific embodiment will enable most spraying operations to be carried out using a smaller number of switch operations than would be possible if only the switch pairs were available.

Claims

1. A motor control system for a plurality of electric motors connected in parallel characterised by a first rail (14) of a power supply (10) for each motor (11, 12, 13) being connectable to a first polarity of power supply (10); a second rail (15) being connectable to the other or another polarity of power supply by way of a switching arrangement (23, 23A, 23B, 37, 41) such that in the first position of the arrangement the second rail (15) is connected to all the motors (11, 12, 13) and in the second position of the arrangement the second rail (15) is only connected to a given motor if an independent switch (24/25, 24A/25A, 24B/25B) for a motor (11, 12, 13) is in an operation-enabling-position for that motor.

2. A control system as claimed in Claim 1 characterised by: (A) each motor (12) having a first switch (25) with an output (7) coupled to the motor (12) and first (8) and second (9) inputs; and a second switch (24) having an input (28) coupled to a first line (31) by a diode (32), and first (29) and second (30) outputs; the first input (8) of the first switch (25) being coupled by one channel (26) to a first output (29) of the second switch (24); the second input (9) of the first switch (25) being coupled by another channel (27) to the second output (30) of the second switch (24); the one channel (26) being connected to a second line (33) by a diode (34); the other channel (27) being connected to a third line (35) by a diode (36); the first (25) and second (24) switches being ganged to ensure that in a given position they are coupled to a common channel (26, 27); and (B) switching comprising a master switch (37) whereby the second (33) or third line (35) can be coupled to a first output (43) of a changeover switch (41), a second output (45) of the changeover switch (41) being coupled to the first line (31), an input (42) to the changeover switch (41) being coupled to the second rail (15); the changeover switch (41) being operable to connect one or other output (43, 45) to the input (42).

3. A control system as hereinbefore described with reference to and as illustrated in the accompanying drawing

4. A mobile spraying system comprising a series of spray booms coupled to a storage tank for liquid for spraying by way of pipework incorporating a series of motorised valves and a pump characterised by a motor control system for the valves sa claimed in Claim 1, Claim 2 or Claim 3.

5. A trailer for attachment to a towing vehicle on which is mounted a spraying system as claimed in claim 4.