© 2004, ‘07 STI
05/07
POWER
SWITCH
RF
TX BURST
RF
TX/RX
RANGE
DETECTION
SIGNAL
PROCESSOR
VOICE
PROCESSOR
AUDIO
AMPLIFIER
SOUND
SELECTION
SPEAKER
This device may not cause interference. This device must accept any interference, including interference that may cause un-
desired operation of the device. Changes or modifications not expressly approved by the manufacturer could void the user’s
authority to operate the equipment. 1. “Watch-Dog” is a structure of “RF TX/RX” device that transmits an RF signal, then de-
tects the reflecting RF signal and senses the range. It then converts the signal to an audio alarm voice. The carrier frequency
is generated by an LC resonant circuit “TR8”, “L3”, “C34”. Center frequency is 2.4G Hz, ASK/100% modulated, 4K modulation
signal, 1/10 duty. 2. The power switch is used to control the “Watch-Dog” system power. 3. Within the signal processing
module, there is a “RF TX burst” section. It will generate a burst pulse to control the RF module and then turn the RF trans-
mission on. 4. When an object comes within detection range, it will reflect the RF energy back to the RF receiver. 5. The RF
receiving module will demodulate the RF signal to the “signal-processing” module. 6. The range detection section will process
an incoming signal and then send it to the “voice processor”. 7. The “voice processor” will send a different sound based on
the “sound selection switch”. It will transmit from the “audio amp” to the speaker.
Made in Taiwan.
FCC Approval
2306 Airport Rd.
Waterford, MI 48327
POSTAGE
REQUIRED