SAFETY SYSTEM FOR
SPECIAL SHORT-RANGE WIRELESS EQUIPMENT
NOTE: THE MANUFACTURER IS NOT RESPONSIBLE FOR ANY RADIO OR TV
INTERFERENCE CAUSED BY UNAUTHORIZED MODIFICATIONS TO THIS EQUIPMENT.
SUCH MODIFICATIONS COULD VOID THE USER’S AUTHORITY TO OPERATE THE
EQUIPMENT.
CONTENTS
1. GENERAL DESCRIPTION
1-1 INTRODUCTION
1-2 TECHNICAL FEATURES
1-3 COMPOSITION
2. SPECIFICATION
3. FUNCTIONAL DESCRIPTION
4. ADJUSTMENT
5. MAINTENANCE AND TROUBLE SHOOTING
1. GENERAL DESCRIPTION
1-1 INTRODUCTION
This device is a safety system for short-range wireless equipment named as
"DK-SEVA-01" which uses UHF 447.725 MHz frequency.
This device is remote controller to be used for an emergency when weapon detector
system is being operated.
1-2 TECHNICAL FEATURES
1-2-1 This device is designed to use semiconductor and integrated circuit system for
the high credibility.
1-2-2 This device is designed to meet the need of legal frequency tolerances and
frequency range by adopting the crystal oscillating circuit system.
1-2-3 Voltage is applied by 3 VDC button cell battery
1-3 COMPOSITION
This device is composed of as follows
- Transmission unit
* RF section
* CPU section
- Antenna
- Battery
- Mechanical parts
2. SPECIFICATION
2-1 Radio Frequency : 447.7250 MHz
2-2 Channel Spacing : 12.5 KHz
2-3 Frequency Stability : +/- 7 ppm
2-4 Max. Frequency Deviation : +/- 2.5 KHz
2-5 Modulation : FSK
2-6 Emission Mode : F1D
2-7 Transmission Power : 10 mW
2-8 Transmission : One Way
2-9 Code Format : 24 bit Address, 4 bit Data
2-10 Code Memory : CPU ROM
2-11 Power Supply : One 3.0 VDC Button Cell Battery
2-12 Operating Temperature : -10 to +60
2-13 Dimension : Approx. 53 mm x 32 mm x 13 mm
2-14 Weight : Max. 100g
3. FUNCTIONAL DESCRIPTION
3-1 Operation Switches and indicator
3-1-1 LED : It is lighted when remote control button is pressed
3-1-2 Switch 1 : It activates remote controller
3-1-3 Switch 2 : It deactivates Switch 1 and cancels the phone calls from the system
controller
3-2 Front View of System
1) Key holder
2) LED1
3) SW1
4) SW2
4. ADJUSTMENT
4-1 Measuring Equipment
- Frequency Counter
- DC Power Supply
- Modulation Meter
- RF Transmission Zig
- RF Amplifier
4-2 Measuring Method
4-2-1 Equipment Connection
< Measuring Equipment Connection Diagram >
4-2-2 Adjustment Method
NO. Items Method Points* Limits
1 RF Out Power DC 3V Supply VC1 10mW
2 Frequency DC 3V Supply VC2 447.3500MHz
447.4250 MHz
+/- 7 ppm
3 Modulation dev. DC 3V Supply C6 = 8pF +/- 2.5 KHz
* reference : parts layout
5. MAINTENANCE AND TROUBLE SHOOTING
5-1 Checking
5-1-1 Are all buttons operating ?
5-1-2 Is LED operating ?
5-1-3 Is batter voltage correct ?
5-1-4 Check if trouble is from RF or Control section
5-2 The cause of the trouble
5-2-1 Remote controller does not operate at all
- Dead battery or bad wire connection
- Bad connection at switch
- Bad CPU
5-2-2 LED does not light
- Bad LED
- Bad R20 resister
- Bad CPU
5-2-3 Week Transmission Power
- Battery change
- Mis-tuning ( power or frequency re-tuning )
- Bad Q4, Q5, Q6 at high power
- Bad pin 3 of CPU at high power
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