A simple electronic device called the 555 Timer Based Animal Repeller Circuit has been cleverly designed to keep animals away from certain areas.
This device works by producing a high pitched sound that many animals find uncomfortable but humans usually can not hear it.
The main part of this device is the IC 555 timer chip, which is set up to create these high frequency sounds.
It generates noises in the ultrasonic range around 15 kHz to 120 kHz
This circuit is easy to put together and runs well on a 9V battery making it a great choice for home use.
Circuit Working:
Parts List:
| Component | Specification | Quantity |
|---|---|---|
| Resistors (1/4W) | 1.2k, 4.7k | 1 each |
| Preset | 4.7k | 1 |
| Capacitor | Ceramic 10nF | 1 |
| IC | NE555 | 1 |
| Piezo Buzzer | 82dB | 1 |
| Switch | SPST | 1 |
| Battery | 9V | 1 |
The design of the circuit is based on the IC 555 timer chip working in its astable mode.
The frequency of the oscillation is determined by the combination of resistors R1 the adjustable resistor VR1 preset and R2 along with capacitor C1.
The output from the 555 IC is used to power a piezo buzzer, which makes an ultrasonic sound when it gets electricity.
You can change the sounds frequency by tweaking the preset VR1.
Since animals can hear high frequency sounds really well, this noise can be very uncomfortable for them causing them to leave the area.
Important Note:
This device is made to keep the unwanted animals away without hurting them.
It makes a high pitched sound that is just uncomfortable enough to make them want to go somewhere else, but it wont hurt them.
Make sure to keep it at least 1 meter (or 3 feet) away from where our pet sleeps or eats so they do not get stressed out.
Formulas with Calculations:
The below mentioned are the formulas with calculations for Simple 555 Timer Based Animal Repeller Circuit:
The frequency of the astable multivibrator using the 555 timer IC is given by the formula:
f = 1.44 / [(R1 + 2VR1) * C1]
where,
- f is the frequency of oscillation in Hz
- R1 is the fixed resistor 1.2k
- VR1 is the variable resistor 4.7k preset
- C1 is the capacitor 10nF
To calculate the frequency range:
When VR1 is at minimum 0Ω the total resistance is R1 + 2(VR1) = 1.2kΩ f_max = 1.44 / [(1.2kΩ) * 10nF] = 120 kHz
When VR1 is at maximum 4.7kΩ the total resistance is 1.2kΩ + 2(4.7kΩ) = 10.6kΩ f_min = 1.44 / [(10.6kΩ) * 10nF] = 13.6 kHz
Thus, the frequency can be varied from approximately 13.6 kHz to 120 kHz covering the ultrasonic range.
How to Build:
To build a Simple 555 Timer Based Animal Repeller Circuit follow the below mentioned steps:
- Gather all the components as mentioned in the above circuit diagram.
- Connect pin 1 of IC1 to GND of the circuit.
- Connect pin 2 and pin 6 of IC1
- Connect capacitor C1 from pin 2 of IC1.
- Connect pin 3 of IC1 to one end of piezo buzzer and other end of piezo buzzer connect to GND of the circuit.
- Connect resistor R1 and VR1 from pin 2 and pin 7 of IC1.
- Connect resistor R3 from pin 7 of IC1 to positive supply of the circuit
- Connect pin 4 and pin 8 of IC1 to positive supply of circuit.
- Connect a SPST switch from positive supply of the circuit to +9V battery and the negative of 9V battery connect to GND of the circuit.
Conclusion:
This Simple 555 Timer Based Animal Repeller Circuit works by producing an ultrasonic sound that animals dislike.
It uses a 555 timer IC set up in astable mode, which makes it simple to create and use.
The circuit is small and can run on a 9V battery, making it an affordable and portable way to keep other small animals away.