1. Detailed Block Diagram “Stretching” the Signal…
Senior Project – Electrical Engineering The Baby Protector: Baby Monitor to protect against dogs Ermin Arias Advisors – Prof. Hassib & Prof. Hedrick
My Idea
Motivation
To modify a commercially available baby monitor by combining it with an invisible dog fence. This will train the pets to remain within a specified distance from the infant’s crib.
My sister recently had a baby
In the United States thirty-nine percent1 of the households own a dog.
Detailed Block Diagram
Transmitter next to monitor continuously sends RF signal
Signal goes into microprocessor
Receiver in dog collar receives signal and generates shock IF necessary
555 Timer
Signal received by receiver, goes thru third comparator = add hysterisis to get rid of instability
Transmitter sends a signal to the receiver in the parents unit
Shock triggers the comparator
Transistor Inverter
Voice signal produced and injected into monitor’s microphone
“Stretching” the Signal…
Conclusion
The device has been tested and it meets the performance criteria.
Detects receiver in collar up to 12ft away
Sends a wireless notification to the parent unit up to 650ft away.
Figure 4: Signal after going thru timer.
Note: Signal has expanded to last 8 milliseconds
Figure 3: Signal as received from the comparator into the timer. Each pulse has an ON time of 15 microseconds