When your dog barks constantly at night, surely crossed your mind that there is something you do not know. Dogs have the ability to adapt situations to maximize the sensitivity of night vision in low light. Warnings from the barking dog are an early warning of a Barking dog alarm, by utilizing the ability of dogs to see the object
moving than at rest in the dark.
Barking dog alarm is going to use the voice captured through a condenser microphone and ultimately will turn on the lights in a certain time interval where as if the occupants had been notified. Alarm circuit is very useful and can be placed in a dog cage. The alarm is quite easy to build and is something pretty good idea.
How Barking Dog Alarm Works
Condenser microphone (the alarm) mounted in the dog’s cage will perceive the sound bark and produces an AC signal, which pass through the DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 with T2 will strengthen the voice signal and provide current pulses from the collector of T2. Trigger input pulses applied to the collector of transistor T3 and combined with capacitor C3 to the base of the transistor T4, which causes the T4 Cutt-off. The collector voltage of transistor T4 forward biases transistor T3 through resistor R8.
Barking Dog Alarm Circuit
Transistor T1 conducts and capacitor C3 discharges to keep transistor T4 cut-off. Transistor T4 remains cut-off until capacitor C3 charges enough to enable it to conduct. When transistor T4 conducts, its collector voltage goes low to drive transistor T3 into cut-off state. Resistor R9 and capacitor C3 are timing components. When fully charged, capacitor C3 takes about two minutes to discharge. So when sound is produced in front of the condenser mic, TRiAC1 (BT136) fires and the bulb (B1) glows for about two minutes.
Assembly Instruction
Assemble the barking dog alarm circuit on a general-purpose PCB and enclose in a plastic cabinet. Power supply to the circuit can be derived from a 12V, 500mA step-down transformer with rectifier and smoothing capacitor. Solder the triac ensuring sufficient spacing between the pins to avoid short circuit. Fix the unit in the dog’s cage, with the lamp inside or outside as desired. Connect the microphone to the circuit using a short length of shielded wire. Enclose the microphone in a tube to increase its sensitivity.
Warning
Since the circuit uses 220V AC, many of its points are at AC mains voltage. it could give you lethal shock if you are not careful. So if you don’t know much about working with line voltages, do not attempt to construct this circuit. Any kind of resulting loss or damage will be your responsible. (Taken from Night Alert by D. Mohan Kumar)
Barking dog alarm is going to use the voice captured through a condenser microphone and ultimately will turn on the lights in a certain time interval where as if the occupants had been notified. Alarm circuit is very useful and can be placed in a dog cage. The alarm is quite easy to build and is something pretty good idea.
How Barking Dog Alarm Works
Condenser microphone (the alarm) mounted in the dog’s cage will perceive the sound bark and produces an AC signal, which pass through the DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 with T2 will strengthen the voice signal and provide current pulses from the collector of T2. Trigger input pulses applied to the collector of transistor T3 and combined with capacitor C3 to the base of the transistor T4, which causes the T4 Cutt-off. The collector voltage of transistor T4 forward biases transistor T3 through resistor R8.
Barking Dog Alarm CircuitAssembly Instruction
Assemble the barking dog alarm circuit on a general-purpose PCB and enclose in a plastic cabinet. Power supply to the circuit can be derived from a 12V, 500mA step-down transformer with rectifier and smoothing capacitor. Solder the triac ensuring sufficient spacing between the pins to avoid short circuit. Fix the unit in the dog’s cage, with the lamp inside or outside as desired. Connect the microphone to the circuit using a short length of shielded wire. Enclose the microphone in a tube to increase its sensitivity.
Warning
Since the circuit uses 220V AC, many of its points are at AC mains voltage. it could give you lethal shock if you are not careful. So if you don’t know much about working with line voltages, do not attempt to construct this circuit. Any kind of resulting loss or damage will be your responsible. (Taken from Night Alert by D. Mohan Kumar)
