Title:
TOOL OPERATED SWITCH FOR VACUUMS
Kind Code:
A1


Abstract:
A vacuum control system allows the vacuum to be turned on and off automatically based on the operation of an associated power tool. The vacuum is able to run at full power without sacrificing power to the power tool itself. Additionally, a pneumatic power tool may be used to control the operation of the vacuum.



Inventors:
Loveless, Michael (Price, UT, US)
Loveless, Spencer (Price, UT, US)
Palmer, Todd (Salt Lake City, UT, US)
Mabey, Kent Walker (West Jordan, UT, US)
Application Number:
12/357300
Publication Date:
10/01/2009
Filing Date:
01/21/2009
Primary Class:
International Classes:
A47L5/00
View Patent Images:
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Primary Examiner:
MULLER, BRYAN R
Attorney, Agent or Firm:
Dentons Durham Jones Pinegar (Lehi, UT, US)
Claims:
1. A vacuum comprising: a portable vacuum having a motor and a power cord; a socket for providing power to a power tool other than the vacuum; a sensor for sensing the operation of the power tool; and a control module for receiving a signal from the sensor and for selective providing a signal to the relay to thereby switch the motor on and off.

2. The vacuum of claim 1, wherein the control module is configured for switching the motor on when the power tool is turned on, for leaving the motor on if the power tool is turned off after a period of time less than a specified period of time, and for switching the motor off if the power tool is turned off after operating for more than the specified period of time.

3. The vacuum of claim 2, wherein the control module is configured for switching off the motor when the power tool is turned off if the motor was on before the power tool was switched on.

4. The vacuum of claim 1, further comprising a port for receiving a signal from a remote switch to thereby control the operation of the motor.

5. A system comprising the vacuum of claim 1, wherein the vacuum comprises first communications means for communicating remotely with a remote switch; and wherein the system further comprises a remote switch separate from the vacuum, the remote switch comprising: a connection which is connectable to a source of power for a power tool; a connection which is connectable to a power tool to thereby provide power to the power tool; a sensor for sensing when the power tool is operating; and second communications means for communicating with the vacuum such that the operation of the power tool controls the operation of the vacuum motor.

6. The system of claim 5, wherein the first communications means comprises an electrical connector, and wherein the second communications means comprises a cable for connection to the electrical connector.

7. The system of claim 5, wherein the first communications means comprises a wireless receiver, and wherein the second communications means comprises a wireless transmitter for communication with the wireless receiver.

8. The system of claim 5, wherein the connection which is connectable to a source of power is a power cord.

9. The system of claim 5, wherein the connection which is connectable to a source of power is an air hose.

10. A vacuum system for use with a power tool comprising: a vacuum, the vacuum comprising a vacuum motor and a hose for connecting the vacuum to a power tool; a control module for controlling the operation of the vacuum motor; and a signal receiving device for communicating with a remote switch; a remote switch separate from the vacuum comprising: a connector which is connectable to a source of power suitable for powering a power tool; a connector which is connectable to a power tool so as to provide said source of power to the power tool to thereby operate the power tool; a sensor for sensing the operation of the power tool; and a signal transmitting device for communicating with the control module; and wherein the control module operates the vacuum motor according to the operation of the power tool.

11. The system of claim 10, wherein the control module operates the vacuum motor to turn the vacuum motor on when the power tool is turned on and to turn the vacuum motor off when the power tool is turned off.

12. The system of claim 10, wherein the control module operates the vacuum motor to turn the vacuum motor on when the power tool is turned on, keep the vacuum motor on when the power tool is turned off if the power tool was operated for less than a predetermined period of time; and turn the vacuum motor off when the power tool is turned off if the power tool was operated for more than a predetermined period of time.

13. The system of claim 12, wherein the control module further operates the vacuum motor to turn the motor off when the power tool is turned off if the vacuum motor was turned on before the power tool was turned on.

14. The system of claim 10, wherein the signal receiving device comprises an electrical socket and the signal transmitting device comprises an electrical cable.

15. The system of claim 10, wherein the signal receiving device comprises a wireless receiver and the signal transmitting device comprises a wireless transmitter.

16. A method for controlling a vacuum comprising: selecting a vacuum having a vacuum motor and a hose; selecting a control module for receiving a signal indicating the operation of a power tool and for controlling the operation of the vacuum motor in accordance to the operation of the power tool; selecting a power tool; using the vacuum in concert with the power tool to perform a task; and operating the vacuum so that the vacuum is turned on and off according to the operation of the power tool.

17. The method of claim 16, wherein the method comprises selecting a remote switch separate from the vacuum, the remote switch comprising a connector connectable to a power source for the power tool, a connector connectable to the power tool to thereby power the tool, and a signal transmitting device for transmitting a signal to the control module; connecting the vacuum to an electrical outlet; connecting the remote switch to a power source separate from the electrical outlet; connecting the power tool to the remote switch; the remote switch sensing the operation of the power tool; and the remote switch transmitting a signal to the control module to indicate the operation of the power tool; and the control module operating the vacuum motor according to the operation of the power tool.

18. The method of claim 17, wherein the power tool is electric, and wherein the remote switch is connected to an electrical outlet which is different than the outlet to which the vacuum is connected to thereby power the power tool.

19. The method of claim 17, wherein the power tool is pneumatic, and wherein the remote switch is connected to a source of compressed gas.

20. The method of claim 16, wherein the step of operating the vacuum comprises, more specifically, the control module operating the vacuum motor to turn the vacuum motor on when the power tool is turned on, keep the vacuum motor on when the power tool is turned off if the power tool was operated for less than a predetermined period of time; and turn the vacuum motor off when the power tool is turned off if the power tool was operated for more than a predetermined period of time.

21. The method of claim 20, wherein the control module operates the vacuum motor to turn the vacuum motor off when the power tool is turned off if the vacuum motor was on before the power tool was turned on.

Description:

1. RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application Ser. No. 61/022506, filed Jan. 21, 2008, which is expressly incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates to a switch for controlling a vacuum. More specifically, the present invention relates to a switch for turning a vacuum on and off by sensing operation of a tool which is used in combination with the vacuum.

2. State of the Art

Due to health concerns and a desire to reduce the mess of dust and debris, vacuums (typically canister vacuums as shown herein) and dust collection shrouds or guards are becoming increasingly common. These dust collection systems are used in many situations such as concrete grinding or paint removal to capture the debris which is generated. The debris is, in many cases, hazardous to the health. Where hazardous debris such as concrete dust or paint dust is generated, it is even more important to capture the dust and debris.

There are many situations where a worker is not using the desired tool for a long period of time, but is using the tool intermittently. In these situations, it is desirable to turn off the vacuum when the tool is not in use so as to conserve energy and reduce the noise level. It is, however, inconvenient to switch the vacuum on and off manually.

As shown in FIG. 1, vacuums 10 have been made which provide power to an electric tool and which operate the vacuum when the tool is operated. The vacuum 10 includes a power cord 14 which is plugged into a wall outlet to provide power to the vacuum and to an additional tool. The vacuum includes a socket 18 which receives the power cord of the desired tool, such as a drill or grinder. The socket 18 is electrically connected to the power cord 14 so as to provide power to the tool. The vacuum 10 includes an internal controller which powers the vacuum motor when the tool is powered. The vacuum 10 turns on when the tool is turned on and turns off when the tool is turned off. The vacuum 10 also has a typical on/off switch 22 so that the vacuum can be placed in a permanent on position.

FIG. 2 shows a schematic diagram of the vacuum electrical components for the vacuum of FIG. 1. The vacuum power cord 14 is connected to a controller 26 and switch 22 and thereby provides power to both the vacuum motor 30 and the socket 18. The socket 18 always receives power when the power cord 14 is plugged into a power source so that a desired power tool can be operated. When the power tool is being operated, the controller 26 provides power to the vacuum motor 30. The controller 26 provides surplus power which is not being used by the power tool to the vacuum motor 30 so as to not overload the electrical outlet that the power cord 14 is plugged into. In this manner, the vacuum will run when the associated power tool is being operated and turn off when the power tool is turned off. The switch 22 allows the vacuum to be turned permanently on, disabling the socket 18 at the same time.

The prior art vacuum of FIG. 1 has several drawbacks. One drawback is that the vacuum 10 can only operate automatically when used with an electrical tool and not other tools such as a pneumatic tool. Another drawback is that the worker must switch the vacuum 10 on and off at the vacuum itself to have the vacuum run continuously, such as when cleaning up stray debris after performing some work with a power tool. The vacuum 10 may be located away from the worker and this may cause additional inconvenience and difficulty.

Another drawback of the vacuum 10 is that the power tool and the vacuum both share a common power supply. The power cord 14 provides power to both the vacuum and the power tool. Most wall outlets will provide a maximum of 15 amps of current, less a 20% safety margin, resulting in a 12 amp allowable load. Many vacuums are designed to draw nearly 12 amps so as to maximize the suction generated by the vacuum. Power tools, however, commonly draw 7-12 amps. Many angle grinders as may be used with the vacuum 10 will draw a full 12 amps. Because of the high power draw of the tools commonly used with the vacuum, the vacuum motor 30 is often only allowed to draw 3 amps or less so as to not overload the electrical circuit powering the vacuum 10 and the power tool. The vacuum 10 will provide very little air flow and little suction when operating at 3 amps or less. Thus, the vacuum 10 is not operating at full power when used with a power tool and will not adequately collect the dust and debris due to the reduced air flow and suction.

There is a need for a tool operated vacuum which overcomes the limitations of the prior art. There is a need for a vacuum which is automatically switched on and off when a power tool is switched on and off which still operates under full power even when the power tool is operating. There is a need for a vacuum which can be remotely switched on and off for continuous operation. There is also a need for a vacuum which can be remotely switched by an air powered tool.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved vacuum control system which operates a vacuum based on the operation of an associated power tool.

According to one aspect of the invention, the vacuum draws full power even when an associated power tool is being operated. The vacuum will thus always generate full suction and air flow and will properly collect the dust and debris.

According to another aspect of the invention, the vacuum may be switched into and out of a continuously operating state remotely.

According to another aspect of the invention, the vacuum may be switched on and off by an air tool and not just an electrically operated tool.

These and other aspects of the present invention are realized in a vacuum control system as shown and described in the following figures and related description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein:

FIG. 1 shows a perspective view of a prior art vacuum.

FIG. 2 shows a schematic diagram of the electrical system of the vacuum of FIG. 1;

FIG. 3 shows a perspective view of a vacuum and control system according to the present invention;

FIG. 4 shows another perspective view of a vacuum and control system according to the present invention;

FIG. 5 shows a schematic diagram of the vacuum control system of the present invention;

FIG. 6 shows an electrical diagram of the vacuum control system of the present invention;

FIG. 7 shows another electrical diagram of the vacuum control system of the present invention; and

FIG. 8 shows another electrical diagram of the vacuum control system of the present invention.

It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention.

DETAILED DESCRIPTION

The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims.

Turning now to FIG. 3, a perspective view of a vacuum and control system of the present invention is shown. The vacuum 50 includes a power cord 54 which provides power to the vacuum motor and to a power socket 58. A power tool may be plugged into the socket 58 and the power tool may be used to control the vacuum 50. A switch 62 is provided to allow the vacuum to be switched on and off in a conventional manner, overriding the tool start features.

The vacuum 50 also includes a port 66 which may be connected to a remote switch 70 via a control cable 74. Additionally, a wireless receiver 66b could be provided for communication with the remote switch 70. The connector 78 on the control cable 74 plugs into the port 66. The remote switch 70 includes a power cable 82 and includes a socket 86 into which a power tool may be plugged. The remote switch 70 includes a sensor which detects when a power tool connected to the socket 86 is on and which sends a signal to the vacuum 50 via the control cable 74 and port 66 to switch the vacuum on. The sensor could be a current sensor, a voltage sensor, etc. The remote switch 70 may additionally include a wireless transmitter 66a.

FIG. 4 shows an alternate embodiment of the vacuum control system of FIG. 3 where the remote switch 70 is configured for operation with a pneumatic tool, such as a die grinder. The switch functions similarly to that of FIG. 3, but includes an air hose 82a instead of a power cord 82 and includes an air hose 86a instead of a socket 86. The air hose 82a is configured for connection to an air supply and the air hose 86a is configured for connection to a pneumatic power tool. The sensor for a pneumatic tool may be a flow sensor, pressure sensor, reed switch, etc. When the pneumatic sensor senses air flow to the pneumatic tool, a signal is sent to the vacuum 50 via control cable 74.

Although a wired connection between a remote switch 70 and the vacuum 50 is shown in FIGS. 3 and 4, a wireless connection is also possible, and may be preferred in situations where the extra cords may pose a safety risk or may simply hinder a worker's performance. Typically, the port 66 and cord 74 are replaced by a wireless transmitter and receiver, such as a radio frequency transmitter and receiver.

Turning now to FIG. 5, a schematic diagram for the vacuum and control system of the present invention is shown. The vacuum 50 may be operated in a conventional manner via switch 62. The vacuum 50 includes a controller 90 (such as a relay or a triac) to switch the motor 94 on and off as is desired. An additional control module 98 may be utilized to operate the sensor 102 or perform other functions. The vacuum 50 may be operated without the remote switch 70. Sensor 102 detects when a power tool connected to socket 58 is being operated, such as by sensing the current drawn by the tool. The sensor 102 is connected to the control module 98, which receives and interprets signals from the sensor and sends a signal to the module 90 to thereby operate the motor 94.

The control module 90 is programmed to optimize control of the vacuum and provide additional functionality for a user. According to a preferred embodiment, the control module 90 is programmed to turn the motor 94 on when a power tool connected to the socket 58 is turned on, and to turn the motor 94 off when the power tool is turned off after the power tool has been operated for longer than a predetermined time period, such as two seconds. If the power tool is turned off after having operated for less than two seconds, the control module 98 does not turn the motor 94 off. The control module 90 is further programmed to always turn the vacuum motor 94 off when the power tool ceases to be used if the vacuum motor was running prior to operating the power tool, as this would typically indicate that the operator desires to turn the vacuum motor off after using the vacuum 50 without using the power tool.

In this manner, the vacuum motor 94 will operate when the power tool is being used and will turn off after discontinuing use of the power tool, as nearly all uses of a power tool will require longer than two to six seconds. The worker may, however, operate the power tool for only a second or so to turn the vacuum motor 94 on and leave the motor on without the power tool being on. This would allow the worker to clean up some debris or perform other tasks requiring the vacuum but not the power tool. The worker may then turn the vacuum off by again briefly turning the tool on. The control module 98 thus allows a worker to switch the vacuum on and off and operate the vacuum in a continuous run state without having to operate the switch 62 on the vacuum itself. This is useful in situations such as where the worker is on a ladder and does not have the vacuum nearby. Preferably, the control module 98 is also programmed to operate the vacuum motor 94 for a few seconds after a worker uses a power tool for an extended period and then stops using the power tool. In this manner, the vacuum motor captures any debris which is within a tool dust shroud as the tool comes to rest.

When the vacuum 50 is operated as described above, the power tool and the vacuum motor 94 will still share power from a single power cord 54, reducing the power available to the vacuum motor 94 while the power tool is operating. The vacuum 50 does, however, allow a worker greater ease and flexibility in operating the vacuum as described above. One benefit provided is that the vacuum motor 94 may continue to run for a few seconds after a worker discontinues using a power tool. This increases the effectiveness of the vacuum 50 in capturing the dust and debris which is generated. An additional significant benefit is that the user may remotely switch the vacuum on and off by quickly blipping the tool on for less than a threshold period of time. This “cleanup” mode allows the worker to capture any stray debris and otherwise use the vacuum without using the power tool without having to turn the vacuum on and off with switch 62. This significantly increases the ease and effectiveness with which a worker may use the vacuum 50, making it more likely that the worker will properly use the vacuum. Increased worker compliance in using the vacuum 50 is highly beneficial where the dust and debris is hazardous, such as when grinding concrete or removing corrosion resistant paint.

In addition to the benefits discussed above, the remote switch 70 allows a worker to operate a power tool in combination with the vacuum 50 to control the vacuum without sacrificing vacuum power. The remote switch also gives a worker a larger area where the power tool may be used without moving the vacuum 50 itself. The remote switch 70 uses a separate power source such as power cord 82 (or air supply line 82a) to provide power to a power tool. If the power tool is electrical, the power cord 82 and power cord 54 will typically be connected to different electrical circuits so that the circuit breaker does not limit the available power, allowing both the power tool and the vacuum motor 94 to operate at full capacity.

In use, the remote switch 70 is connected to the vacuum via cable 74 and port 66 (or wireless connection as discussed). The remote switch 70 includes a sensor 106 which senses operation of the power tool connected to the socket 86 (or air hose 86a). The sensor 106 may sense current, voltage, or voltage drop for an electrical power tool, or may sense air flow, pressure, or pressure drop for a pneumatic power tool. When the sensor 106 senses that the power tool is being operated, it sends an electrical signal via cable 74 to the control module 98 to thereby trigger operation of the vacuum motor 94 as discussed above. Typically, the remote switch 70 sends either a voltage signal to the control module 98, or provides continuity between two wires in cable 74. Providing continuity between two wires is advantageous where a pneumatic remote switch 70 is used, as a reed switch or the like which closes the switch when air flow is present can be used to send a signal to the control module 98 without any power requirement at the remote switch 70. Thus, the remote switch 70 can connect two wires in cable 74 to thereby provide a voltage signal, ground a terminal, or provide electrical continuity within the control module 90. For pneumatic tools, the sensor 106 may also receive power from the vacuum itself so that the remote switch 70 does not need a separate power supply. Alternately, pneumatic tools may utilize a reed switch or other un-powered switch which simply opens or closes continuity between two wires to indicate air flow. According to a preferred embodiment, the remote switch may be provided with a wireless transmitter 66a and the vacuum is provided with both a port 66 and a wireless receiver 66b.

As is seen in FIG. 5, the signal output from the remote switch 70 passes through the control module 98. As such, the use of a tool connected to the remote switch uses all of the on/off features as discussed above. The remote switch 70 thus allows a power tool to control operation of the vacuum 50 as discussed above without limiting the power available to the vacuum motor 94, and allows a pneumatic tool to control operation of the vacuum motor. The vacuum 50 will turn on and off with the power tool where the power tool is used for extended periods of time, and the power tool may be turned on briefly to place the vacuum in a continuous run state. Where the power tool is electric, the power tool may draw a high current such as 12 amps while still allowing the vacuum motor 94 to draw the intended current, often 10 to 12 amps. Because the remote switch 70 controls the vacuum motor 94 via the control module 90, the remote switch and associated power tool may be used to turn the vacuum motor on and off and place the vacuum motor in a continuous run state as described above to allow the worker to clean up debris or perform other tasks which require only the vacuum and not the power tool. Additionally, the use of an extended cord 74 or a wireless connector 66a, 66b as discussed allows a person greater range from the vacuum 50, allowing them to work more freely without being encumbered by moving around the vacuum.

Turning now to FIGS. 6 and 7, electrical circuit diagrams for the controller circuitry associated with the vacuum 50 and remote switch 70 are shown to illustrate one manner in which the electrical components of the above vacuum may be constructed. FIG. 6 illustrates circuits associated with the vacuum operation while FIG. 7 illustrates circuits associated more with the remote switch 70.

Turning now to FIG. 6, a circuit 110 is shown to illustrate one manner of construction for the vacuum 50 to implement the methods discussed above. The circuit 110 includes the following sections: a DC power supply 114, a current sensing circuit 118, a micro-controller 122, a remote switch power supply circuit 126, a remote switch input circuit 130, a zero crossing circuit 134, and a output driver circuit 138. As discussed previously, a switch 62 may be used to control the operation of the vacuum 50. Typically, a three position switch 62 is used, having on off position, an on position where the vacuum runs continuously, and an ‘auto’ position where the vacuum operation is controlled by the circuit 110. A DC power supply 114 is typically used because most electronic components are designed to operate on DC voltage where most vacuum motors 94 operate on AC voltage.

As regards the particular electronic components, E1 through E7 represent connections or connectors and J2-1 through J2-6 are junctions. For the current sensing circuit 118, T1 is a CSE187L current sensing transformer, R1 is a 68 ohm resistor, C5 is a 0.1 μF capacitor, CR1 is a MBR0520 diode, R2 is a 2 k ohm resistor, and C1 is a 1 μF capacitor. For the DC power supply circuit 114, CR3 are BAV23C diodes, C2 is a 220 μF capacitor, and R3 is a 680 ohm resistor. For the zero crossing circuit 134, R4 is a 100 k ohm resistor, CR2 is a 914 diode, and A2 is a PS2701 opto isolator. For the output driver circuit 138, Q1 is a BTA24-600B triac, R7 is a 100 ohm resistor, R6 is a 560 ohm resistor, C4 is a 0.1 μF capacitor, R5 is a 1 k ohm resistor, A3 is a MOC3023 optocoupler, R12 is a 10 k ohm resistor, and Q3 is a 2222 transistor. For the microcontroller circuit 122, A1 is a 12HV615 PIC microchip. For the remote start input circuit 130 and the remote start power supply circuit 126, VR1 is a LM317LCPK integrated circuit, R10 is a 40 ohm resistor, Q1 is a 2222 transistor, R8 is a 33 ohm resistor, and R9 is a 33 ohm resistor. For the remote surrent sensing circuit of FIG. 7, T1 is a CSE187L, R1 is a 100 ohm resistor, CR1 is a 914 diode, CR2 is a MBR0520 diode, C1 is a 1 μF capacitor, R2 is a 10 k ohm resistor, Q1 is a 2222 transistor, Q2 is a 2907 transistor, R4 is a 27 k ohm resistor, R3 is a 4.7 k ohm resistor, DS1 is a LED, R5 is a 200 ohm resistor, CR3 is a HD04 bridge diode.

In the circuit 110, the hot wire of the plug 54 is connected to point 146 and the neutral wire of the plug 54 is connected to neutral, the wire 150 is connected to the hot wire of the power input plug 54, the hot wire of the vacuum motor 94 is connected to point 154, and the neutral wire of the vacuum motor is connected to neutral as indicated at 158.

The micro-controller 122, zero crossing circuit 134, and output driver circuit 138 correspond to the functions performed by the control module 90 as shown in the schematic diagram of FIG. 5. The current sensing circuit essentially contains a current transformer, a filter, and a rectifier. The output of the current sensing circuit is connected to an analog to digital converter on the micro-controller 122, and the micro-controller is capable of a cycle by cycle reading of the total current level through the system.

The zero output circuit 134 consists of a rectifier and opto-isolated transistor. The output of this circuit is a square wave with edges coincident with the zero crossings of the AC line voltage. The output of the zero crossing circuit 134 is connected to an internally pulled up input of the micro-controller 122. The software in the micro-controller 122 is dependant on the zero-crossing of the AC line voltage. The firing of the output driver circuit must be in sync with the line voltage. When the software senses the zero-crossing, the timings start for the phase angle firing of the output driver to thereby adjust the power output of the motor 94.

The basic operation of the micro-controller 122 is to sense the current through the system as provided by the current sensing circuit 118 and phase-angle fire both the positive and negative waveforms to the output triac 162 driving the vacuum motor such that the overall current of both the vacuum motor 94 and any power tool connected to the socket 58 stays below a pre-determined limit. The micro-controller 122 may also be programmed to include a minimum amount of current that the vacuum motor 94 requires to operate effectively. If the current to the vacuum motor 94 gets too low, the vacuum motor will turn off until the attached power tool is turned off.

The micro-controller 122 is preferably programmed to sense when current through the line (socket 58) starts (corresponding to a tool start when the vacuum switch 62 is in the auto position) and turn on the vacuum motor 94 in response. The micro-controller 122 also senses a drop in the current (a tool shutoff) and turns the vacuum motor off after about a 6 second delay to clear the vacuum hose. The current drop sensing logic has about a 2 second startup delay to allow for the transient effects of starting the power tool and vacuum motor 94 to decay. This means that if the current start logic sees a tool start, the vacuum will immediately turn on. If the tool is turned off within the 2 seconds, the current drop sensing logic will not see the tool current go away and the vacuum will stay on indefinitely. As discussed, this allows a user to remotely turn on the vacuum without keeping a tool running by operating the tool for less than two seconds. This feature works for both the socket 58, as sensed by the current sensing circuit 118 and the remote switch 70. In both cases the vacuum can be shut off by turning the power tool on, then back off again, whether quick or long, as the current drop sensing logic has been enabled.

The vacuum circuit 110 may include a power supply circuit 126 to provide a small amount of power to the remote switch 70 if such is necessary. Power may be provided to the remote switch 70 at point 170. The remote start power supply circuit 126 typically consists of a current limiter to prevent too much current being drawn through the remote switch 70 and provides a voltage for the remote sensing circuit. The output of the remote switch 70 is connected to the remote switch input circuit 130 at point 174, and drives a transistor 166 which is connected to an internally pulled-up input of the micro-controller 122. When the remote switch 70 passes current, the micro-controller 122 will turn on the vacuum motor 94. When the remote switch 70 ceases to pass current, or ceases to display a current through a power line, the vacuum motor 94 will turn off after the 6 second delay. Circuit points 170 and 174 are typically a two pin connector used to connect the cable 74 to the vacuum 50 and thereby connect the remote switch 70 to the controller circuitry 110.

It will be appreciated that if the remote switch 70 is used instead of connecting an electrical power tool directly to the socket 58, the remote switch may be connected to a wall outlet on a separate circuit breaker so that the vacuum 50 and power tool do not have to share power. Thus, the power tool may draw current and the vacuum motor 94 may draw full current without concerns of overloading the circuit. Even if the remote switch 70 is used, the internal logic of the microcontroller 122 may still operate to keep the overall current of the vacuum below the pre-determined level by phase angle firing the vacuum motor if needed. This may provide some protection if the vacuum motor 94 alone attempts to draw an unusually high current.

Turning now to FIG. 7, a circuit diagram for a remote switch 70 for use with electrical power tools is shown. The remote switch 70 would include a current sensing circuit 178 which consists of a current transformer 182 which drives a transistor network so as to provide a signal to the micro-controller 122 through point 190 as soon as current is sensed. Point 186 and 190 on the remote switch current sensing circuit 178 are connected to points 170 and 174, respectively, on the vacuum circuit 110 when the remote switch 70 is used. The current transformer 174 and transistor network are preferably selected such that the current sensing circuit 178 is activated with about 1 Amp of current and thereafter drives the circuit 178 to give a logic change to the micro-controller 122. The current limited voltage from the remote start power supply circuit 126 may be used to power the remote sensor circuit 178.

Turning now to FIG. 8, a functional parts diagram for a remote switch 70 for use with pneumatic tools is shown. As discussed, the use of a remote switch 70 allows for controlling the vacuum 50 based on the usage of pneumatic tools. In this case, the remote sensor may be a simple switch. There may be no electronics in the remote switch 70 other than a reed switch or simple switch that closes when air is passing through the switch and opens when the air stops flowing.

Thus, the pneumatic remote switch 70 may include a switch 198 that is closed so as to conduct electricity when air flows through an air passageway 202. As shown in FIG. 4, the passageway 202 is typically connected to an air hose 82a which is configured for connection to an air supply and an air hose 86a which is configured for connection to a pneumatic power tool. The switch 198 is connected via electrical leads to points 206, 210, which are connected to points 170, 174 on the circuit 110 when the remote switch 70 is connected to the vacuum via cable 74. Thus, point 206 provides an electrical voltage to the switch 198. When the switch 198 is closed due to air flow, the voltage is transmitted to point 210 and thereby to point 174 on circuit 110 to cause the micro-controller 122 to operate the vacuum motor in the manner discussed above. Alternatively, the switch 70 may use a wireless transmitter 66a as discussed.

There is thus disclosed an improved system for controlling the operation of a vacuum with an associated power tool. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.