Synchronized primary winding current shunting technique for controlling electro-stimulus level

#The present invention relates generally to electronic remote training collars and the like and also to collar-mounted electronic “bark limiter” or dog bark training devices, and more particularly to improvements therein which reduce the size, weight and power consumption thereof without reducing the open circuit stimulus voltage, allow convenient manual adjusting of stimulus levels, provide improved sensing of what constitutes valid barking, provide low-power standby operation when the dog is not barking, and allow monitoring of the amount of valid barking that actually occurs.

#A variety of electronic dog training collars have been utilized for applying electrical shock and/or audible stimulus to a dog when it barks. In many situations it is highly desirable to prevent individual dogs or groups of dogs from barking excessively. For example, one dog's barking in a kennel is likely to stimulate other dogs to bark. This is undesirable with respect to the welfare of the dogs themselves and nearby people. Similar problems occur in neighborhoods in which there are dogs that are kept outside at night: if one dog starts barking others are likely to join in, causing a general disturbance.

#The closest prior art is believed to include the present assignee's Bark Limiter product and commonly assigned U.S. Pat. No. 4,947,795 by G. Farkas entitled “Barking Control Device and Method”, issued Aug. 14, 1990 and incorporated herein by reference. U.S. Pat. No. 4,947,795 discloses a bark training device which allows a dog to control the level of electrical stimulus in response to its own barking behavior. This patent discloses circuitry in a collar-mounted electrical device that detects the onset of barking and initially produces only a single low level electrical stimulus pulse that gets the dog's attention, but does not initially produce a highly unpleasant level of stimulation. If the dog continues barking, the stimulation levels of the electrical shock pulses are increased at the onset of each barking episode in a stepwise fashion until the stimulus becomes so unpleasant that the dog stops barking for at least a predetermined time, e.g., one minute. After that minute elapses, the circuitry resets itself to its lowest initial stimultion level and remains inactive until barking begins again, and then repeats the process, beginning with the lowest level of stimulation and increasing the stimulus level if barking continues. In one embodiment, a certain duration, e.g., 30 seconds, of “watchdog barking” is permitted before the initial stimulus pulse is applied to get the dog's attention, after which continued “nuisance barking” results in gradual increasing in the intensity of the aversive stimulus up to a maximum level until the barking stops for at least one minute. However, the assignee's above mentioned Bark Limiter product does not use the algorithm described in U.S. Pat. No. 4,947,795 for producing increased stimulation in response to increased levels of barking, and instead provides a fixed duration stimulation with detection of an initial onset of barking, and provides a half second duration of stimulation with two seconds of pause, which is easily implemented and has been proven to be very effective.

#FIG. 1 is a perspective view of a collar-mounted bark limiter unit of the present invention with the collar removed.

#FIG. 2 shows the a partially-exploded view of the bark limiter unit of FIG. 1.

#FIG. 3A is a perspective exploded view of the bark limiter unit of FIGS. 1 and 2.

#To summarize, a preferred embodiment of a dog bark limiter of the present invention provides convenient manual adjustability of the applied stimulus level to be applied to the neck of the dog by means of a switch. The bark limiter also includes low power circuitry that improves the electrical stimulation scheme to provide adequately high open circuit voltage between the stimulus electrodes in a small, lightweight collar-mounted animal training product at both high and low selected stimulus levels. The described bark limiter includes a motion detector that detects characteristic motion of the dog's neck produced as a result of barking and in response automatically powers up the circuitry from a very low power stand by operating condition.

#A technique of “valid” bark detection using software wherein a capture and compare routine is executed in software executed by a microcontroller to accomplish the function of, in effect, generating a frequency spectrum of the received sound and comparing it with a predetermined frequency spectrum to determine if the sound constitutes a “valid” bark. A “bark counter” function is provided that counts the number of valid barking episodes by the dog. A self-test mode is provided to self-test or verify operability of the neck motion sensor and the sound vibration sensor. Whenever an electrical stimulus is applied to the dog's neck, then a 4 second “relaxation” delay is allowed to elapse before any further stimulus can be applied, in order to prevent a stimulus-caused barking cycle from being established.

#Referring to FIGS. 1, 2, 3A and 3B, bark limiter 1 includes a housing 2 having a lower section 2A and an upper section 2B. The top surface 9 of upper housing section 2B is slightly concave, to better accommodate the curvature of a dog's neck. A pair of collar-retaining loops 3 are attached to opposite ends of upper housing section 2B, as shown. A typical dog collar (not shown) is passed through loops 3 around the bottom surface of housing 2 to fasten bark limiter 1 to the dog's neck. Two stimulus electrodes 5 are threaded into receiving holes 8 (FIG. 2) in the upper surface 9, and their conductive tips are pressed against the dog's neck to make electrical contact therewith when the collar is tightened. As indicated in FIG. 2, stimulus electrodes 5 are removable. In accordance with one aspect of the present invention, a preferably non-conductive stabilizing post of the same height as stimulus electrodes 5 is rigidly attached to upper surface 9, and is offset from a straight line between stimulus electrodes 5 so the stabilizing post 7 and the two stimulus electrodes 5 define a triangle. This prevents the conductive electrode tips of stimulus electrodes 5 from “rocking” against the dog's neck and avoids or at least reduces the occurrence and severity of sores on the dog's neck that are sometimes caused by the pressure of the stimulus electrodes against the dog's skin. The stabilizing post 7 in conjunction with the stimulus electrodes 5B and 5C provides stable contact of all three with the dog's neck and allows the direction of the collar to be reversed so that stabilizing post 7 and stimulus electrodes 5B and 5C make contact with different areas on the dog's neck, which reduces the occurrence and of and severity of neck sores.