3. Approach To establish the necessity for an animal deterrent device designed for high-voltage applications, a clear illustration of the problems animals cause must be discussed. A general working model also needs to be used to explain the basic operations of the device. Once a straightforward representation has been demonstrated to the reader, each one of the theoretical sections of the device will be discussed in further detail. 3.1. General Background Information Animal deterrent devices are designed to discourage animals from getting close to or nesting in a specific area. Animals cause multiple problems when nesting, feeding, or traveling near high-voltage areas. In this environment there are many open-air contact connections. These connections can be ‘shorted’ by the animal, animal waste, or nesting material deposited by animals. Animal related power outages account for a large percentage of the annual power outages experienced by electric utility companies nationwide [1]. These power outages reduce the reliability of the electrical power distribution system, while elevating the utility company's cost of providing electric power. 3.1.1. Types of Deterrents Currently, there are many types of animal deterrents on the market. Common deterring methods include audible warnings, visual warnings, physical barriers and even olfactory type devices. Audible deterrents are the most popular deterrents used by the electric utility industry. Current audio deterrents constantly emit a sound at one or several ultrasonic frequencies. The problem with this approach is that animals become accustom to the constantly emitted noise rendering the device ineffective. Another type of animal deterrent is a physical animal barrier. Physical barriers are commonly used by utility companies. Physical barriers have been created for poles, conductor lines, and substation perimeter fences. A major limitation of this type of deterrent is that it is only effect against climbing animals such as squirrels. A large percentage of animal related outages are caused by birds, which these animal deterrents cannot control. Physical deterrents mainly use barrier devices, but in high-voltage areas it is impossible to barricade every possible entrance to the high-voltage device. The two remaining types are olfactory and visual deterrents. Olfactory deterrents use predator smells and other deterring odors to repel the targeted animal away from high-voltage areas. This method also has been found to be ineffective due to the amount of odor causing substance needed to be effective. 3.2. General Working Model The Mitigator design will incorporate two main deterrent methods, audio and visual. To create an effective animal deterrent using audio and visual deterrent methods requires a fairly complex system of hardware and software. Figure 1 shows the general circuit board layout of the design. The audio circuit will require a sound input at a specific voltage level modulated to a desired frequency. The input must be feed into an audio amplifier circuit to reach the desired signal amplitude to drive the speaker. The most effective lighting system consists of a variable rate high intensity flash known as a strobe light. Strobe lights normally operate in the 3000 to 4000 volt range. Voltages of this magnitude require special design considerations when it comes to circuit board layout to insure isolation of the high-voltages. The signal to turn the strobe light on must be generated by a motion detector, so the light flashes only when an animal is in the target area.Both the lighting and audio components have power requirements and size restrictions, because the enclosure that houses the components must be built on a small scale to be mobile and cost efficient to produce. This presents a problem as can be seen in the following sections. After adding both deterrent methods, plus extra features it still must be approximately half the size of the nearest competitor. A proposed image of the design is shown in Figure 2. Figure 1: General Circuit Board Layout Figure 2: Proposed Image of Design3.3. Motion Sensors 3.3.1. Alternatives There are many types of sensors that can be used to detect physical movement. Some commonly used types of passive-infrared (PIR), active-infrared, ultrasonic, capacitive, inductive, video, and microwave motion sensors. A problem shared by many of these sensor types is the sensor cost and complexity. Many of the mentioned motion sensor configurations have high hardware costs. A more important problem with many of these sensor types are the limitations on the types of objects that these devices can detect. The methods used by many of these motion sensors prevent them from being useful or even operating correctly in the environment in which the Mitigator will be used. The Mitigator will be used in areas of high electromagnetic interference (EMI), rendering many sensors unusable. Sensors that measure surrounding capacitance and inductance have limitations on the types of objects that it can detect. A common problem with the capacitive sensor is that it uses an electromagnetic field which is emitted from the sensor and detects changes in the electric field by measuring capacitance. The major flaw with this sensor is that the high EMI environment around the sensor will render it useless. This sensor also is dependant on the dielectric properties of the objects around the sensor, as it reacts differently to materials with different dielectric constants [2]. A fairly more common sensor is an ultrasonic sensor. This type of motion sensor uses an ultrasonic transducer to emit an ultrasonic sound wave which reflects off of objects and the signal is received back through the transducer. Ultrasonic motion sensors have been in existence before other motion sensing technologies. However, it is difficult to calibrate an ultrasonic motion sensor to achieve normal operation. This type of sensor would have frequent false triggers and would result in the device turning on and off frequently throughout the day. Most false triggers from ultrasonic sensors would come from ambient sounds, especially when the device is located near homes or urban areas where noise is high during the day. The Mitigator uses ultrasonic sound as one method of deterring animals. The output of the ultrasonic speaker would interfere with the motion sensor sensing, making this sensor
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