Diablo Controls DSP-222 Operation Manual Download Page 10

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DSP222H_Manual_A

Page 10 of 17

R4, 13

27K 1/8 watt SMD 1206

generic

R6, 15

56K 1/8 watt SMD 1206

generic

Q3, 6-8, 10-12

2N3904 NPN SMD SOT-23 transistor

Motorola MMBT3904LT1

Q1, 2, 4, 5, 9

2N3906 SMD SOT-23 transistor

Motorola MMBT3906LT1

S1, 2

6 position right angle DIP switch

Switronic DA06BTS

T1, 2

Potcore isolation transformer

Diablo P/N XFM060

20 Mhz Xtal-parallel 20 pF HC-49UA

Fox 200-20-1

Summary of Contents for DSP-222

Page 1: ... Detector Sensor Unit This manual contains technical information for the DSP 222 detector sensor unit Included are general description general characteristics installation procedure adjustment instructions operational guide maintenance procedures and technical schematics and drawings ...

Page 2: ...between 50 and 750 microhenries with a loop system Q as low as 5 The unit will detect inductance changes as small as 0 01 L L 3 Installation and Adjustments The sensor unit is factory shipped with all switches set to off signifying both channels are disabled The MIN PRESENCE jumper J1 located on the printed circuit board is installed forcing all detection outputs to last a minimum of 100 ms in the...

Page 3: ...er the change in loop frequency is very small perhaps as little as one hertz It is easy to measure a change of one hertz simply by counting the number of cycles in one second Unfortunately the minimum response time using this method is easily greater than one second To improve the response time the measurement is done by gating a high speed stable oscillator with the loop frequency This scheme cal...

Page 4: ...lator The loop is connected to the oscillator circuit with the isolation transformer T1 T2 The reflected roadway loop inductance is resonated with the capacitor C5 C11 Frequency modification capacitors C3 C9 and C4 C10 are switched in via SW1 SW2 and are used to change the operating frequency of the loop circuit Neon surge arrestor I1 I2 provides high voltage spike protection When loops are connec...

Page 5: ...incorrectly In addition an input resistor R36 is provided to reduce inrush current when the unit is plugged into a hot card cage The input voltage is well filtered with C16 6 Preventive Maintenance Over the years the electronic components used in inductive loop detectors have become very reliable Generally most inductive loop sensor problems can be traced to the loop system The loop system is defi...

Page 6: ...oltages below this may result in the sensor unit entering a reset state In this case the unit will appear to be non functional b Reset line held low This fault is likely to affect all units in the rack since the external reset line is usually common to every card rack position Measure the voltage on the external reset line If it is below approximately 12 volts remove each unit one by one until the...

Page 7: ...tor R36 b Regulated 12 volt power supply Voltage at output of U3 across capacitors C17 should be 12 2 volts Possible component fault is the voltage regulator U3 c Regulated 5 volt logic power supply Voltage at output of U2 should be 5 2 volts Possible component fault is the voltage regulator U2 d Regulated 5 volt oscillator power supply Voltage at output of U4 should be 5 0 2 volts Possible compon...

Page 8: ...Observe the square wave to be the same frequency as the loop oscillator At this point a simulated call should be introduced at the test box Observe a slight frequency increase at this point If there is no square wave at this point a defective component in the oscillator circuit may exist Possible components at fault are Q1 Q4 Q2 Q5 Q3 Q6 D3 D4 or the potcore isolation transformer T1 T2 h Outputs a...

Page 9: ...D 123 Diodes Inc MMSZ5257B 2 D1 2 11V transorb SMD SMB Diodes Inc SMBJ11CA 2 LED3 4 Right angle green LED Bivar H101CSGC 2 LED1 2 Right angle red LED Bivar H101CSRC 2 I1 2 NE 2E neon indicator Xenell 2 4 3 8 Phil self tap screw generic 2 4 40 5 16 screw w washer generic 2 Right angle bracket Diablo P N HDW025 1 Handle Diablo P N HDW030 2 6 3 8 Phil self tapping screw generic 2 U2 4 5V regulator SM...

Page 10: ...eric 7 Q3 6 8 10 12 2N3904 NPN SMD SOT 23 transistor Motorola MMBT3904LT1 5 Q1 2 4 5 9 2N3906 SMD SOT 23 transistor Motorola MMBT3906LT1 2 S1 2 6 position right angle DIP switch Switronic DA06BTS 2 T1 2 Potcore isolation transformer Diablo P N XFM060 1 X1 20 Mhz Xtal parallel 20 pF HC 49UA Fox 200 20 1 ...

Page 11: ...DSP222H_Manual_A Page 11 of 17 10 Block Diagram 11 Schematic next page ...

Page 12: ...DSP222H_Manual_A Page 12 of 17 This page left intentionally blank Remove and insert B size schematic ...

Page 13: ... channels Loop Input The loop inputs incorporate lightning and transient protection devices and the loop oscillator circuitry is transformer isolated The lightning protection will withstand the discharge of a 10 microfarad capacitor charged to 2 000V across the loop inputs or between any loop input and earth ground ...

Page 14: ...sates for environmental changes and effects throughout the entire tuning range and operating temperature range Fault Monitoring Internal monitoring of the loop system is accomplished with the microcontroller The system is able to detect shorted or open loop systems as well as a sudden change of inductance exceeding 25 of the nominal value If a fault is detected on a channel the Fail LED will flash...

Page 15: ...he pulse mode a vehicle remaining over a loop will inhibit further pulse outputs from being issued for a period of 2 seconds after which time vehicles passing over the loop will again be detected Sensitivity One of seven settings may be selected to optimize detection on varying loop and lead in configurations Sensitivity is defined as the minimum percentage change in L L of the total inductance lo...

Page 16: ...a ground true logic level to the reset input pin C for a period exceeding 15 microseconds Electrical Interconnection Edge Connector mates with connector types Cinch 50 44A 30 Pins Function A Power and logic common B Input power 24 volts DC C Reset D Loop 1 E Loop 1 F Output 1 collector H Output 1 emitter J Loop 2 K Loop 2 L Chassis ground M N C N N C ...

Page 17: ...ersions the output transistor is rated for a maximum collector voltage of 30 VDC Maximum collector current is 50 mA Mechanical Dimensions 1 12 W x 4 5H x 7 0 Excluding handle Environmental Temperature Range Storage 55C to 85C Operating 37 C to 74 C Humidity 0 to 95 relative ...

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Diablo Controls DSP-222, Operation Manual

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