Cat repeller circuit

With this cool cat repeller circuit you could chase the cats off from any where you want.In fact, I designed this circuit to chase my cat from my computer table.Most of the animals like cats respond violently to ultrasonic sound and in fact it’s the best way to chase them off.This principle is employed in this circuit.
The circuit here is nothing but an astable multi vibrator wired around NE555 (IC1).The produces an ultrasonic sound in the range 15-20Khz.The NE 555 is enough to drive a small piezo buzzer and no amplification stages are needed.The POT R2 can be used to adjust the frequency of sound.

Notes.

* The circuit can be powered from a 9V battery or the power can be tapped from your computer SMPS.
* The circuit can be assembled on a general purpose PCB.

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Park Aid Modification

This modification was designed on request: some people prefer an audible alert instead of looking at the LED display, making easier the parking operation.
 Parts:

R15_____________3K3 1/4W Resistor
R16___________330K 1/4W Resistor
R17___________470K 1/4W Resistor
R18___________150K 1/4W Resistor

C6______________1µF 63V Electrolytic or Polyester Capacitor

D8,D9,D10____1N4148 75V 150mA Diodes

IC4_____________555 Timer IC

BZ1___________Piezo sounder (incorporating 3KHz oscillator)





The original Park-aid circuit was retained, but please note that the input pins of IC2B, IC2C and IC2D are reversed. LEDs D5, D6 and D7, as also resistors R12, R13 and R14 are omitted. IC2B, IC2C and IC2D outputs drive resistors R15, R16 and R17 through D8, D9 and D10 respectively, in order to change the time constant of a low frequency oscillator based on the 555 timer IC4.

This allows the Piezo sounder to start beeping at about 2 times per second when bumper-wall distance is about 20 cm., then to increase the beeps to about 3 per second when bumper-wall distance is about 10 cm. and finally to increase further the beeps frequency to more than 4 beeps per second when the distance is about 6 cm. or less.

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Safety Guard

Protect your home appliances from voltage spikes with this simple time delay circuit. Whenever power to the appliances is switched on or resumes after mains failure, the oscillator starts oscillating and D5 blinks. This continues for three minutes. After that, Q14 output of IC CD4060 goes high to trigger the gate of the SCR through D4. At this moment, the voltage is available at the cathode of the SCR, which energizes the relay coil to activate the appliance and D6 glows. Switch SW1 is used for quick start without waiting for delay. 

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Solar Powered Animal Scarer

Here is a solar powered Flasher to scare away the nocturnal animals like bats and cats from the farm yard or premises of the house. The brilliant multicolored flashes confuse these animals and they avoid the hostile situation. It is fully automatic, turns on in the evening and turns off in the morning.

The circuit has an LDR controlled oscillator built around the Binary counter IC CD 4060.The functioning of the IC is controlled through its reset pin 12. During day time, LDR conducts and keeps the reset pin of IC high so that it remains dormant. During night, LDR cease to conduct and the reset pin will be grounded through VR1. This triggers the IC and it stats oscillating using the components C1 and VR2. Output pins 7, 5 and 4 are used to power the LEDs strings.

VR1 adjusts the sensitivity of LDR and VR2, the flashing rate of LEDs. High bright Red, Blue and White LEDs are used in the circuit to give brilliant flashes. Red LEDs flash very fast, followed by blue and then White. White LEDs remains on for few seconds and provide light to a confined area. More LEDs can be added in the strings if desired. The circuit can also function with 12 volt DC.

Animal Repellent Circuit Diagram

The circuit uses a solar powered battery power supply. During daytime, battery charges through R1 and D1.Green LED indicates the charging mode. During night time current from the solar cell decreases and D1 reverse biases. At the same time D2 forward biases to provide power to the circuit. Resistor R1 restricts the charging current and the high value capacitor C1 is a buffer for current.

Animal Scarer Solar Power Supply

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