There are two US Patents protecting the Pest-A-Cator's technology, and to satisfy your curiosity here is their text. To see the asociated illustrations and view the original patents go to the official US Patent and Trademark Office Website and enter the patent numbers 4,802,057 and 6,400,995.

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United States Patent 4,802,057
Patterson ,   et al. January 31, 1989

Rodent control device

Abstract

An improved rodent control device for generating a pulsating and interrupted magnetic field offensive to rodents in buildings includes a housing, an electrical circuit for generating the pulsating magnetic field and an electrical supply member for electrically connecting the electrical circuit with an AC power source. The electrical circuit includes a low voltage circuit for generating a pulsed and interrupted frequency gating signal, a signal amplifying device, and a high voltage circuit that produces a pulsed and interrupted high voltage output signal in response to the gating signal of the low voltage circuit and includes a magnetic field generator for receiving the output signal from the high voltage circuit and generating a pulsating and interrupted magnetic field in response to the output signal.


Inventors: Patterson; Charles R. (Ames, IA); Lutz; Gary E. (Ames, IA)
Appl. No.: 142438
Filed: January 11, 1988

Current U.S. Class: 361/232 ; 116/22A
Field of Search: 367/139 340/384E 43/124 116/22A 361/232


References Cited [Referenced By]

U.S. Patent Documents
4215429 July 1980 Riach
4338593 July 1982 Mills
4414653 November 1983 Pettinger
Primary Examiner: Tarcza; Thomas H.
Assistant Examiner: Lobo; Ian J.
Attorney, Agent or Firm: Pingel; G. Brian Herink; Kent A.

Claims



I claim:

1. A rodent control device for generating a pulsating magnetic field offensive to rodents in buildings, said device comprising:

(a) a housing;

(b) an electrical supply means having hot and neutral lines for connection to a source of high voltage AC electrical power and associated with said housing to supply said power to the interior thereof;

(c) low voltage circuit means for generating a pulsed frequency gating signal;

(d) rectifying and voltage regulating circuit means connected in series to said hot and neutral lines for reducing and rectifying said high voltage AC power to a regulated low voltage DC electrical power that serves as a supply voltage to said low voltage circuit means;

(e) high voltage circuit means connected to said hot and neutral lines for providing a pulsed high voltage output signal in response to the gating signal of said low voltage circuit means;

(f) amplifying means for amplifying the frequency gating signal from said low voltage circuit means;

(g) circuit isolating means that is physically connected to said amplifying means and said high voltage circuit means and is actuated by the amplified gating signal from said amplifying means to provide a corresponding pulsed gating signal to said high voltage circuit means, said isolating means serving to electrically isolate said low voltage circuit from said high voltage circuit;

(h) said high voltage circuit means includes a magnetic field generating means that is connected to the hot line of said electrical supply means and receives said pulsed gating signal and generates a pulsating magnetic field in response thereto;

(i) conductive means connected to the neutral line of said electrical supply means and associated with said magnetic field generating means in such fashion that an electrical current is established in said conductive means in response to said pulsating magnetic field, which current produces lines of pulsating magnetic flux about said conductive means and said neutral line of said electrical supply means.

2. A rodent control device as recited in claim 1 wherein said high voltage circuit means includes a gating means that is actuated in response to actuation of the circuit isolating means and is connected with a voltage and current limiting means that protects the gating means from electrical spikes produced by said magnetic field generating means.

3. A rodent control device as recited in claim 1 wherein said magnetic field generating means is connected to the input of said gating means and produces said pulsating magnetic field upon actuation of said gating means.

4. A rodent control device as recited in claim 3 wherein a light emitting diode is connected to said amplifying means and is actuated upon the actuation of said amplifying means to indicate the device is in an operational mode.
Description



BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to devices for controlling the population of rodents in buildings and more specifically relates to an improved rodent control device that produces a pulsating and interrupted frequency resulting in an offensive magnetic field generation that acts as an irritant to rodents.

2. Description of the Prior Art

A wide variety of rodent control devices are known in the art. Many such devices operate on the basis of producing a low frequency of approximately 60 cycles per minute which is known in the art to be offensive to rodents such as rats and mice. For purposes of efficiency and long life operation, it has been found that the frequency generated does not have to be continuous, but instead, these devices operate effectively in spite of an interruption of the frequency at predetermined intervals. To provide the required frequency and the predetermined interruptions, the majority of prior art devices have employed a wide array of mechanical switching type devices requiring relatively frequent maintenance or replacement.

One improvement to the above devices is a unit that utilizes electronic switching components as disclosed in U.S. Pat. No. 4,414,653 issued Nov. 8, 1983. As described in the "653" Patent, the disclosed unit is designed to be utilized with a three wire electrical wiring system whereby the electrical wiring ground line serves as the path of conductive flow for the frequency generated by the unit.

A second improvement to the above devices is disclosed in U.S. patent application Ser. No. 06/787,490 which provides a control device adapted to be employed with common two wire electrical wiring systems found in most buildings and utilizes circuitry including an isolating means to electrically separate low and high voltage portions of the circuit to provide a more efficient and safety oriented type of circuitry.

The present invention is an improvement over the invention disclosed in the "490" Application. It is adapted to provide a simplified and more efficient circuit than that disclosed in such application.

SUMMARY OF THE INVENTION

The present invention provides a rodent control device for generating a pulsed and interrupted magnetic field offensive to rodents in buildings. The device includes a housing, electrical supply means having hot and neutral lines, electronic circuitry for producing a pulsating and interrupted magnetic field that is supplied to a conductive means associated with said neutral line to conduct such magnetic field about the building in which the rodent population is desired to be controlled.

The electronic circuitry of the invention includes a low voltage circuit means for generating a pulsed and interrupted frequency gating signal, a current amplifying means for amplifying the gating signal, high voltage circuit means to provide a pulsed and interrupted high voltage output signal in response to the gating signal of the low voltage circuit means, circuit isolating means physically connected to the amplifying means and the high voltage circuit means and actuated by the amplified low voltage gating signal to provide a corresponding gating signal to the high voltage circuit means, and a magnetic field generating means that receives the output signal from the high voltage circuit means and generates a pulsed and interrupted magnetic field in response to such output signal.

The high voltage circuit means includes a gating means that is actuated in response to actuation of the circuit isolating means and is connected with a voltage and current limiting means that protects the gating means from electrical spikes produced by said magnetic field generating means.

The invention is adapted to provide a simplified and more effective and efficient rodent control device that is useable in connection with any type of 115 volt AC outlet and yet is of a sufficiently small size that it takes up little room and attracts little attention.

The invention will appear more clearly from the following detailed description when taken in conjunction with the accompanying drawings, showing by way of example, a preferred embodiment of the inventive idea wherein like numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a reduced perspective view of a rodent control device of the present invention showing a housing and an electrical supply member associated with the housing for supplying electrical power to the interior components thereof; and

FIG. 2 is a circuit diagram of the electronic circuitry of the device of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, a preferred embodiment of an improved rodent control device of the present invention is shown generally at 10 in FIG. 1. The control device 10 is adapted to be used in residential and commercial buildings to provide a safe, efficient and effective means for controlling the rodent population therein. The device 10 operates not on the basis of killing rodents, but rather creates a pulsed and interrupted magnetic field offensive to them. The device 10, therefore, drives away any existing rodents in the buildings and thereafter provides an operative rodent shield for them by supplying the offensive pulsed and interrupted magnetic field generated throughout the buildings.

As shown in FIG. 1, the device 10 includes a generally rectangular housing 11 that is preferrably formed from a high strength plastic but may as well be formed from wood or metal, as desired. In comparison to prior arts devices, the present invention is relatively small as the housing 10 is 2 7/16 inches wide by 4 7/16 inches long by 1 1/16 inches deep.

Housing 11 includes a front wall 12, rear wall 13, side walls 14 and top and bottom walls 15 and 16 respectively. The top wall 15 includes an opening for a light emitting diode 17, and protruding through the rear wall 13 are standard type power supply prongs 18 as customarily used for connection to a normal two prong electrical outlet found in homes and offices for supplying electrical power to electronic circuitry located within the housing 11.

Referring now to FIG. 2, a schematic diagram of a solid state electronic circuit for the device 10 is shown generally at 19. The circuit 19 includes hot and neutral lines 20a and 20b which receive approximately 115 volts AC electrical power via the power supply prongs 17 when plugged into the normal electrical distribution system of a building. Although the lines 20a and 20b are denoted as hot and neutral lines, such denotation is solely for purposes of illustration due to the fact that the electrical power provided to such lines is an alternating current and the lines 20a and 20b will alternate between being hot and neutral.

Connected in series fashion in the line 20a is a resistor 21 and a capacitor 22 which serve as current and voltage limiting devices. Connected across the lines 20a and 20b at its terminals 7 and 1 is an integrated circuit voltage regulator 25 that rectifies the supply voltage and provides approximately a regulated output voltage of 5 volts DC across output terminals 5 and 6. The regulator 25 is an I.C. Max 610 regulator, and also has a terminal 8 connected through a capacitor 26 to ground. Terminals 4 and 2 of the regulator are also connected to ground. A current limiting resistor 27 is connected to the output terminal 6 of the regulator 25 to an output lead 28. The output lead 28 is also connected to the terminal 5 of the regulator 25 and is connected to ground through a capacitor 29.

The five volt DC regulated voltage at the lead 28 is applied across leads 30 and 31 of a duel timing network shown generally at 32. The duel timing network 32 includes an intersil ICM 7556 integrated circuit 33. This type of duel timing network is well known in the art and is described in U.S. Pat. No. 4,414,653 issued Nov. 8, 1983. The integrated circuit 33 includes two different timing circuits to provide an output signal on lead 34 that is pulsed at a desired frequency of approximately one pulse per second and is interrupted at predetermined intervals. Accordingly, an approximately 60 pulse per minute output is present on the lead 34 and exists for a first predetermined period of time and is then interrupted for a second predetermined period of time. Interruption of the output on the lead 34 is not essential to the rodent control operation of the device 10, but for purposes of economy and lifetime of operation of the circuit 19, such interruption is highly preferable.

The timing circuits of the integrated circuit 33 include and are controlled by voltage dividing circuits 37 and 38. The voltage dividing circuit 37 includes resistors 39 and 40 and a capacitor 41 which are chosen appropriately to provide the desired voltage across input terminals 1, 2, and 6 of the integrated circuit 33 to establish a first desired timing sequence for the network 32 to control the frequency of the pulse rate appearing on the output lead 34 (preferably, this pulse rate is approximately one pulse per second with the component values listed in Table I below).

The voltage dividing circuit 38 is formed of resistors 45 and 46 connected to terminal 13 of circuit 33, and a capacitor 47 connected to terminals 8 and 12 of circuit 33, which control the time period during which the pulses on the output line 34 are interrupted (preferably pulses will be conducted on the line 34 for approximately 3 and one half to 4 minutes and then will be absent for a period of 1 and one half to 2 minutes with the component values listed in Table I below). Terminals 3 and 11 of the integrated circuit 33 are connected to ground via capacitors 48 and 49, respectively, and terminal 9 is connected directly to ground.

The output line 34 is connected to resistors 50 and 51, with the resistor 50 together with the light emitting diode 17 forming a circuit branch 52 that is connected to the regulated 5 volt supply voltage lead 28. The resistor 51 is connected to the base 53 of a current amplifying transistor 54. The transistor 54 has an emitter 55 connected by a line 56 to ground, and a collector 57 connected to a resistor 58.

The purpose of the current amplifying transistor 54 is to insure that the low voltage signal from the integrated circuit 33 is sufficiently strong to actuate an opto-coupler 62 (a Motorola MOC3030) through the signal provided by the transistor 54 (an MPS-A13) to terminal 2 of the opto-coupler 62 via the resistor 58. If the signal on line 34 is not of sufficient strength, the opto-coupler will not be actuated as desired and inefficient or ineffective operation will result. Thus, the signal from the integrated circuit 33 actuates the transistor 54 and the amplified signal from the transistor 54 in turn actuates the opto-coupler 62. Also, when the transistor 54 is actuated, current flows through the circuit branch 52 to actuate the light emitting diode 17 to indicate the device 10 is in operation.

The 5 volt regulated supply voltage is supplied to terminal 1 of the opto-coupler 62 by a line 63. The opto-coupler 62 is a well known device in the art and is used for providing electrical isolation of the low voltage integrated circuit 33, the timing networks 37 and 38 and the transistor 54 from the remaining high voltage circuit means portion of the circuit 19.

When the opto-coupler 62 receives a pulsed and interrupted input at its terminal 2 from transistor 54, it is actuated to optically provide an output on a line 65 that is connected to the coupler's terminal 6. The output on the line 65 is fed to a voltage dividing network formed of resistors 66 and 67 to apply a gating signal via a line 68 to a gate 69 of a triac 70, which is a General Electric SC104V.

An input terminal 71 of the triac 70 is connected through lines 72, 73 and a coil 74 to the electrical hotline 20a. An output terminal 78 of the triac 70 is connected by lines 79 and 80 to the electrical supply neutral line 20b. Also, the line 80 is connected to terminal 4 of the opto-coupler 62. Consequently, when the opto-coupler 62 is actuated, a complete circuit is provided for the operation. of the triac 70 and current will flow through the coil 74 in correspondence to the pulsed and interrupted signal received by the opto-coupler 62. As a result, the coil 74 will provide a pulsing and interrupted magnetic field that is offensive to rodents.

A core 81 of the coil 74 is connected to the neutral line 20b so that the pulsing and interrupted magnetic field will be induced onto the line 20b. Thus, electrical current flows in the line 20b and from there to the entire electrical wiring of the building in which the device 10 is located via the neutral line 20b to produce pulsing and interrupted lines of magnetic flux.

To provide protection for the triac 70 from high voltage transcient voltage spikes due to the pulsing of the magnetic field produced by the coil 74, an RC network 82 is connected across lines 73 and 80. The network 82 has a resistor (100 Ohm) and capacitor (0.1 Microfared) connected in series and is a Rifa PMR 205AB.

Thus, the device 10 provides a safe, efficient and effective economical means for controlling the population of rodents in buildings and is relatively small in size and can easily be enabled simply by plugging into a standard electrical outlet. It will be obvious to those skilled in the art that various modifications can be made as to the details described above. For example, a wide variety of voltage rectifying and regulating circuits can be employed for providing a low supply voltage as well as numerous pulsing circuits for providing a gating signal. Hence, the invention is not to be considered as limited to the particular details given, but should be considered as extending to emcompass all such revisions and modifications as would be obvious to a workman of ordinary skill in the art.

Component values and identification for a preferred embodiment of the rodent control device 10 as described above are as follows:

TABLE 1 ______________________________________ Resistors Component No. Value ______________________________________ 21 1 Watt - 100 Ohms 26 1/4 Watt - 20 Ohms 39 1/4 Watt - 1.0 Mohms 40 1/4 Watt - 1.5 Mohms 45 & 46 1/4 Watt - 470 Kohms 50 1/4 Watt - 510 Ohms 51 1/2 Watt - 51 Kohms 58 1/4 Watt - 220 Ohms 66 1/4 Watt - 1 Kohms 67 1/4 Watt - 2.2 Kohms Capacitors 22 250 Volt - 47 Microfared 26, 29 & 41 25 Volt - 100 Microfared 48 & 49 25 Volt - .01 Microfared 47 50 Volt - 1 Microfared ______________________________________

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United States Patent 6,400,995
Patterson ,   et al. June 4, 2002

Rodent control device

Abstract

A rodent control device generates a pulsating, interrupted electromagnetic field via one or more coil(s) and induces it onto the power line wiring in a building via core(s) linked to the coil(s). The rodent control device circuit is microprocessor controlled which allows automatic sensing of line voltage cycle rates and precise control of coil switching circuitry. The coil(s) are connected to the microprocessor to provide a coil monitoring signal via which the microprocessor detects abnormalities in the coil(s) such as shorts or open circuits. Upon detection of such an abnormality, the microprocessor shuts off control signals to the coil and to an LED indicator until a normal coil condition is sensed. The microprocessor also provides a timed rest signal for shutting down the device for, for example, 2 minutes out of every 6 minute period as a power saving feature.


Inventors: Patterson; Charles R. (Trenton, MO); Cline, Jr.; Thomas D. (Dallas Center, IA)
Assignee: Global Instruments Ltd. (Trenton, MO)
Appl. No.: 309116
Filed: May 10, 1999

Current U.S. Class: 700/79 ; 119/720; 361/143; 43/124
Field of Search: 700/73,79,80 367/139 340/384.2,573.2 361/143 116/22A 119/720,721 43/124


References Cited [Referenced By]

U.S. Patent Documents
4215429 July 1980 Riach
4338593 July 1982 Mills
4414653 November 1983 Pettinger
4802057 January 1989 Patterson
5473836 December 1995 Liu
6111514 August 2000 Cossins et al.
6208100 March 2001 Griesemer et al.
6249417 June 2001 Pippen
Primary Examiner: Grant; William
Assistant Examiner: Frank; Elliot
Attorney, Agent or Firm: Shughart Thomson & Kilroy P.C.

Claims



We claim:

1. A rodent control device, comprising:

a) an AC line voltage input with first and second power terminals being respectively connectable to corresponding first and second leads of an AC line voltage source;

b) a programmed microprocessor;

c) a power supply connected between said line voltage input and said microprocessor to provide rectified DC power to a power input of said microprocessor;

d) one of said first and second power terminals being connected to an interrupt input of said microprocessor to generate an interrupt with each cycle of said line voltage source;

e) a coil; and

f) a switch controlled by a gate connected to a control output of said microprocessor, said switch being operative, in response to a gate control signal from said microprocessor, to selectively close a circuit between one side of said coil and one of said first and second power terminals, an opposite side of said coil being connected to the other of said first and second power terminals, said microprocessor being programmed to periodically send said gate control signal to said gate based upon a predetermined timing cycle controlled by the frequency of line cycle signals received by said microprocessor interrupt input.

2. A rodent control device as in claim 1, and further comprising a ferrous metal core positioned proximate said coil and being attached to one of said first and second power terminals such that an electromagnetic pulse is impressed onto said AC line voltage source with each gate control signal applied to said switch gate by said microprocessor.

3. A rodent control device, comprising:

a) an AC line voltage input with first and second power terminals being respectively connectable to corresponding first and second leads of an AC line voltage source;

b) a programmed microprocessor;

c) a power supply connected between said line voltage input and said microprocessor to provide rectified DC power to a power input of said microprocessor;

d) one of said first and second power terminals being connected to an interrupt input of said microprocessor to generate an interrupt with each cycle of said line voltage source;

e) a coil;

f) a switch controlled by a gate connected to a control output of said microprocessor, said switch being operative, in response to a gate control signal from said microprocessor, to selectively close a circuit between one side of said coil and one of said first and second power terminals, an opposite side of said coil being connected to the other of said first and second power terminals, said microprocessor being programmed to periodically send said gate control signal to said gate based upon a predetermined timing cycle controlled by the frequency of line cycle signals received by said microprocessor interrupt input;

g) a coil monitoring input to said microprocessor;

h) a coil condition monitoring circuit connected between said one side of said coil and said one of said first and second power terminals; and

i) a lead connecting said coil condition monitoring circuit to said coil condition input, said microprocessor being programmed to cease sending said gate control signals to said switch gate as long as an abnormal coil condition is sensed by said coil condition monitoring circuit.

4. A rodent control device as in claim 3, wherein said coil condition monitoring circuit comprises a resistor and a diode connected in series between said one side of said coil and said one of said first and second power terminals one coil, said coil monitoring lead connecting between a junction between said resistor and diode and said coil monitoring input of said microprocessor.

5. A rodent control device as in claim 3, and further comprising:

a) an LED indicator connected between an output pin of said microprocessor and one of said first and second power terminals; wherein

b) said microprocessor is programmed to send control signals to light said LED indicator at the same rate as the gating pulses are applied to said gate and to stop sending control signals to light said LED when abnormal coil conditions are sensed by said microprocessor light said LED at the same rate as the gating pulses are applied to said gate.

6. A rodent control device as in claim 1, wherein there are a pair of coils connected in parallel between said switch and said other of said first and second power terminals.

7. A rodent control device as in claim 1, wherein:

a) said microprocessor is programmed to periodically stop production of said gate control signals for a predetermined time period and then to resume production of said gate control signals after said predetermined time period is over.

8. A rodent control device, comprising:

a) an AC line voltage input with first and second power terminals being respectively connectable to corresponding first and second leads of an AC line voltage source;

b) a programmed microprocessor;

c) a power supply connected between said line voltage input and said microprocessor to provide rectified DC power to a power input of said microprocessor;

d) a coil;

e) a switch controlled by a gate connected to a control output of said microprocessor, said switch being operative, in response to a gate control signal from said microprocessor, to selectively close a circuit between one side of said coil and one of said first and second power terminals, an opposite side of said coil being connected to the other of said first and second power terminals;

f) a ferrous metal core positioned proximate said coil and being attached to one of said first and second power terminals;

g) a coil monitoring input to said microprocessor;

h) a coil condition monitoring circuit connected between said one side of said coil and said one of said first and second power terminals; and

i) a lead connecting said coil condition monitoring circuit to said coil condition input, said microprocessor being programmed to cease sending said gate control signals to said switch gate as long as an abnormal coil condition is sensed by said coil condition monitoring circuit.

9. A rodent control device as in claim 8, wherein:

a) one of said first and second power terminals is connected to an interrupt input of said microprocessor to generate an interrupt with each cycle of said line voltage source; and

b) said microprocessor is programmed to periodically send said gate control signal to said gate based upon a predetermined timing cycle controlled by the frequency of line cycle signals received by said microprocessor interrupt input.

10. A rodent control device as in claim 8, wherein said coil condition monitoring circuit comprises a resistor and a diode connected in series between said one side of said coil and said one of said first and second power terminals one coil, said coil monitoring lead connecting between a junction between said resistor and diode and said coil monitoring input of said microprocessor.

11. A rodent control device as in claim 8, wherein there are a pair of coils connected in parallel between said switch and said other of said first and second power terminals and a pair of cores with each one being positioned proximate a respective one of said coils and with each said core being connected to one of said first and second power terminals.

12. A rodent control device as in claim 8, and further comprising:

a) an LED indicator connected between an output pin of said microprocessor and one of said first and second power terminals; wherein

b) said microprocessor is programmed to send control signals to light said LED indicator at the same rate as the gating pulses are applied to said gate and to stop sending control signals to light said LED when abnormal coil conditions are sensed by said microprocessor.

13. A rodent control device as in claim 8, wherein:

a) said microprocessor is programmed to periodically stop production of said gate control signals for a predetermined time period and then to resume production of said gate control signals after said predetermined time period is over.

14. A rodent control device, comprising:

a) an AC line voltage input with first and second power terminals being respectively connectable to corresponding first and second leads of an AC line voltage source;

b) a programmed microprocessor;

c) a power supply connected between said line voltage input and said microprocessor to provide rectified DC power to a power input of said microprocessor;

d) a coil;

e) a switch controlled by a gate connected to a control output of said microprocessor, said switch being operative, upon receipt of a gate control signal from said microprocessor to selectively close a circuit between one side of said coil and one of said first and second power terminals, an opposite side of said coil being connected to the other of said first and second power terminals;

f) a ferrous metal core positioned proximate said coil and being attached to one of said first and second power terminals;

g) a coil monitoring input to said microprocessor;

h) a coil condition monitoring circuit connected between said one side of said coil and said one of said first and second power terminals;

i) a lead connecting said coil condition monitoring circuit to said coil condition input, said microprocessor being programmed to cease sending said gate control signals to said switch gate as long as an abnormal coil condition is sensed by said coil condition monitoring circuit; wherein

j) one of said first and second power terminals is connected to an interrupt input of said microprocessor to generate an interrupt with each cycle of said line voltage source; and

k) said microprocessor is programmed to periodically send said gate control signal to said gate based upon a predetermined timing cycle controlled by the frequency of line cycle signals received by said microprocessor interrupt input.

15. A rodent control device as in claim 14, wherein said coil condition monitoring circuit comprises a resistor and a diode connected in series between said one side of said coil and said one of said first and second power terminals one coil, said coil monitoring lead connecting between a junction between said resistor and diode and said coil monitoring input of said microprocessor.

16. A rodent control device as in claim 14, wherein there are a pair of coils connected in parallel between said switch and said other of said first and second power terminals and a pair of cores with each one being positioned proximate a respective one of said coils and with each said core being connected to one of said first and second power terminals.

17. A rodent control device as in claim 14, and further comprising:

a) an LED indicator connected between an output pin of said microprocessor and one of said first and second power terminals; wherein

b) said microprocessor is programmed to send control signals to light said LED indicator at the same rate as the gating pulses are applied to said gate and to stop sending control signals to light said LED when abnormal coil conditions are sensed by said microprocessor.

18. A rodent control device as in claim 14, wherein:

a) said microprocessor is programmed to periodically stop production of said gate control signals for a predetermined time period and then to resume production of said gate control signals after said predetermined time period is over.
Description



FIELD OF THE INVENTION

The present invention relates to a rodent control device, and, more particularly, to such a rodent control device which generates a pulsating electromagnetic field within a building. The device is controlled by a programmed microprocessor which precisely cycles a coil on and off at a predetermined duty cycle rate while cycling the device itself on and off, detects and compensates for power line cycle rates by adjusting duty cycle rates of the pulsating field, and detects circuit abnormalities and shuts down or does not energize the coil or LED indicator in the event an abnormality is detected.

BACKGROUND OF THE INVENTION

A number of different electronic rodent control devices have been devised, which have been of varying degrees of effectiveness. U.S. Pat. No. 4,802,057, which is assigned to the present assignee, is an example of such a device. In the '057 patent, a rodent control device incorporates a low voltage integrated circuit timer to generate a pulsed output at an approximate frequency of one pulse per second, with the pulses being periodically stopped for an interim period. An opto-coupler receives the timed pulses from the timer circuit and, in turn, provides an output signal to a voltage dividing circuit which gates a triac switch. The triac is thus periodically switched on at the timed rate of about one pulse per second and, in response, completes a circuit from a first power lead through a coil to a second power lead via the triac. The coil has a core associated therewith which is connected to the second power lead and which induces a pulsed, interrupted electromagnetic field onto the power line such that the entire building wiring system becomes a radiator for the pulsed and interrupted electromagnetic field.

The rodent control device described in the '057 patent has proven to be a very successful consumer product. However, the circuit in the '057 patent is relatively expensive since it requires the use of discrete components, including the rather expensive opto-isolator. Furthermore, it would be desirable if the device could sense abnormal coil conditions, such as coil short and open circuits, and cease operation until normal coil conditions resume. Finally, due to varying line cycle conditions, it would be preferable if the device could automatically adapt its timing cycle for differing power line cycles.

The present invention is intended to be an improvement on the circuit described in the '057 patent.

SUMMARY OF THE INVENTION

The present invention is directed to a rodent control device which generates a pulsating, interrupted electromagnetic field via one or more coil(s) and induces it onto the power line wiring in a building via core(s) linked to the coil(s). The rodent control device uses a circuit controlled by a microprocessor which senses line voltage cycle rates and times the application of electromagnetic pulses to the power line based upon the line voltage cycle rate. The coil(s) are connected to the microprocessor to provide a coil monitoring function via which the microprocessor detects abnormalities in the coil(s) such as shorts or open circuits. Upon detection of such an abnormality, the microprocessor shuts off gate control signals to a coil switching triac and signals to an LED indicator until a normal coil condition is sensed. The microprocessor provides several precise timing cycles including a cycle for activating an LED indicator in synchronism with a time cycle for controlling the application of pulses to the coil(s). In addition, a device rest signal is generated by the microprocessor, for example, for 2 minutes out of every 6 minute period as a power saving feature.

OBJECTS AND ADVANTAGES OF THE INVENTION

The principal objects of the present invention include: providing an improved rodent control device; providing such a rodent control device which applies an accurately timed electromagnetic pulse to a power line to repel rodents; providing such a rodent control device which is controlled by a microprocessor; providing such a rodent control device which does not require an opto-isolator to isolate the logic circuitry from the line voltage; providing such a rodent control device which is self adapting based upon the particular cycle rate of the connected line voltage; providing such a rodent control device in which the microprocessor senses coil conditions and shuts off any gate control signals to a coil operating triac and to an LED indicator when abnormal coil conditions exist, such as short or open circuits; and providing such an rodent control device which is economical and which is particularly well adapted for its intended purpose.

Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.

The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an improved rodent control device in accordance with the present invention.

FIG. 2 is a schematic circuit diagram of the improved rodent control device of FIG. 1.

FIG. 3 is a flow chart diagram illustrating the start-up procedures for the microprocessor controlling the circuit of FIG. 2.

FIGS. 4A, 4B, and 4C are flow chart diagrams illustrating the programmed logic of the microprocessor controlling the circuit of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

Referring to FIG. 1, an inventive rodent control device is illustrated and generally indicated at 1. The rodent control device 1 is contained within a housing 2 with an opening 3 within which an LED indicator 4 is positioned. A standard male power plug 5 extends outward from the housing 2.

Referring to FIG. 2, a schematic diagram illustrates a circuit 11 of the rodent control device 1. In the circuit 1, ordinary 120 VAC household line voltage is applied between terminals 12 and 13. A resistor R1 and capacitor C1 provide a current limiting function. A power supply includes diodes D1 and D2, which form a full wave rectifier, capacitor C2, which provides a voltage spike elimination function, capacitor C3 is a filter while zener diode ZD1 limits voltage applied to VCC (pin 5) of microprocessor IC1 to 5 volts DC. Direct line voltage is applied from terminals 12, 13 to P32 (pin 9) and GND (pin 14) of the microprocessor IC1. P32 acts as an interrupt input for assessing line voltage frequency, as will be explained below.

Capacitor C4 and resistor R2 collectively provide a low cost clock connected to clock pins 6, 7 of the microprocessor IC1. P00 (pin 11) of the microprocessor IC1 is connected to LED1, which is the LED indicator 4 described above. P01 (pin 12) of the microprocessor IC1 provides an output gating signal to the triac Q1 via current limiting resistor R5. When the triac Q1 is gated ON by a high signal on pin P01, it closes a circuit from line voltage terminal 12, through coil CL1 and (optional) coil CL2, and back to line voltage terminal 13.

P33 (pin 18) of the microprocessor IC1, is a coil monitoring input connected via a coil monitoring lead to the junction between resistor R4 and diode D3. This coil monitoring input P33 senses coil conditions during periods when the triac Q1 is switched ON in order to detect abnormal conditions such as coil open or short circuits. In other words, when operation of the coil CL1 is normal, a high logical input will be impressed on pin P33, but abnormal conditions in the coil CL1 will result in a low logical input on pin P33.

Resistor R6 stabilizes the triac Q1 to insure that spurious signals on the pin P01 do not inadvertently trigger the triac Q1. Capacitor C5 and resistor R7 are a snubber circuit which prevents induction "kicks" from coils CL1 and C12 from latching up the triac Q1.

Referring to FIG. 3, an initial start-up loop for the microprocessor IC1 is illustrated. At block 21, the IC1, which can be a Z86 processor, is started up and, at block 22, the registers, ports and stacks are initialized, and, at block 23, the Seconds, Minutes, and Scratch Registers are initialized to their programmed initial values. Block 24 represents a "mumble mode" loop in which the microprocessor IC1 is waiting for a line voltage interrupt at pin P32.

Referring to FIGS. 4A, 4B, and 4C, collectively form a logical flow chart of the program for the microprocessor IC1 after an initial line voltage interrupt (block 25) is sensed on pin P32. At block 28, a decision is made as to whether this is the first interrupt, and, if so, at block 29, the line cycle rate is checked. This is done by timing the interval between the first and second interrupts and setting a line cycle register to 1 if the cycle rate is 60 Hz and to 0 if the cycle rate is 50 Hz. This check is performed only on the first "Pass" or first two interrupt signals. At block 30, the line cycle register value is compared to 1, and, if 1, at block 31, the FSEC register comparison (block 34 described below) is set to 29, but if it is 0, at block 32, then the FSEC register comparison is set to 27.

As would be understood by a person skilled in assembler language programming, a compare block such as block 30, shown in FIG. 4A, represents a subtraction operation and the Z result indicates that the quantities compared were the same (i.e. that the difference was equal to zero). Conversely, the NZ result indicates that the quantities compared were not the same (i.e. that the difference was not zero).

After the first interrupt, at block 33, the FSEC register is incremented by 1. The FSEC register thus counts interrupts, which occur every half voltage cycle. At block 34, the FSEC register value is compared to 29 or 27, depending upon the line voltage cycle, and the cycle repeated until a count of 29 or 27 interrupts (approx. 1/2 second) is reached. Then, at block 35, the FSEC register is cleared, and, at block 41, the LED register is incremented. Only the least significant digit of the LED register is used, and, at block 42, this least significant bit is compared to 1. If it equals 1, then, at block 43, the LED indicator 4 (LED1) is turned On. By contrast, if the least significant bit of the LED register is 0, then, at block 44, the LED indicator 4 is turned Off and, at block 45, the LED register is cleared. The loop encompassed by the blocks 41-45 cycles the LED indicator 4 On for 1/2 second and then Off for the next 1/2 second.

At block 51, the least significant bit of the Coil Register is compared to 1, and, if it equals 1, then the coil operation loop of FIG. 4C is entered. If the least significant bit of the coil register is 0, then the time loop of FIG. 4B is entered.

Referring to FIG. 4C, at block 52, the LED register is again compared to 1 and, if equal to 1, then the coil CL1, and, optionally, the coil CL2 are turned Off, at block 53, by switching Off the triac Q1 via the pin P01 of the microprocessor IC1. If the LED register is not equal to 1, then, at block 54, the Pass One Register is compared to 1, and, if it does not equal 1, then, at block 55, the coil(s) CL1 and CL2 are turned On via the triac Q1. Conversely, if the Pass One register is not equal to 1, then, at block 61, the Pass One register is cleared and, at block 62, a 0.1 Second delay is instituted to allow time to check coil status. At block 63, the Coil Present register is compared to 1, and, if equal to 1, then at block 64, the coil(s) CL1 and CL2 are turned Off by switching Off the triac Q1 and the LED indicator 4 and the loop is returned to the top of FIG. 4A. Conversely, if the Coil Present register is not equal to 1, then the timing loop of FIG. 4B is entered, just as it is from blocks 53 and 55. The loop represented by FIG. 4C thus turns the coil off and on at the same rate as the LED indicator 4, if the coil present register is normal.

Referring to FIG. 4B, at block 71, the Seconds register is incremented, and, at block 72, the Seconds register is compared to the number 119. The loop of FIG. 4A is thus repeated until the Seconds register is equal to 119. When the Seconds register is equal to 119, indicating the lapse of 1 minute, then, at block 73, the Seconds register is cleared and, at block 74, the Minutes register is incremented. At block 75, the Minutes register is compared to 4, and, if equal to 4, then the coil register is cleared at block 81 and the loop returns to the top of FIG. 4A. Conversely, if the Minutes register is not equal to 4, then the Minutes register is compared to 6 at block 82. If it is equal to 6, then, at block 83, the Minutes register is cleared and, at block 84, the Coil register is turned back On (i.e. reset to 1) and the loop is returned to the top of FIG. 4A. If the Minutes register is not equal to 6, then the loop is also returned to the top of FIG. 4A. The loop represented in FIG. 4B, encompassing blocks 71-84, serves to cycle the rodent control device 1 such that it is activated for 4 minutes and then deactivated for 2 minutes. Clearly, any other On/Off cycle time can be set by varying the comparison steps 75 and 82.

While the rodent control device 1 has been described and illustrated in a particular embodiment, changes could be made to the circuitry or the digital logic without affecting the viability of the invention. For example, many different platforms and pin configurations can be used for the microprocessor IC1. Accordingly, it is thus to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.

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