DPM 750S-BL 3½ Digit Backlit LCD Voltmeter Module

The DPM 750S-BL features a 200mV d.c. measurement range with auto-zero and auto-polarity. Decimal points are user selectable. The meter features a negative rail generator which enables the meter to measure a signal referenced to its own power supply GND. A low drift bandgap reference circuit ensures accurate readings over a wide temperature range. LED backlighting ensures excellent readability under low light conditions. The module's low cost means it will suit high and low volume applications. This module is supplied with a plastic mounting bezel. A waterproof seal to IP67 / NEMA 4X is achievable, using the optional BEZ 700-IP bezel.

FEATURES • 12.7mm (0.5") Digit Height • 200mV d.c. Full Scale Reading • 3.0 to 7.5V or 6.0 to 15V d.c. Operation °°CF • Auto-zero and Auto-polarity A mV • Programmable Decimal Points kΩ • LED Backlighting (30mA @ 5V typ.) MHz • Low Battery Warning • Bandgap Reference

TYPICAL APPLICATIONS ORDERING INFORMATION • Precision Instrumentation Systems Stock Number • Power Supply Monitoring Standard Meter DPM 750S-BL • Test Boxes IP67 / NEMA 4X Bezel BEZ 700-IP • Panel-Mount Indication • Low Power Voltage Measurement

ELECTRICAL SPECIFICATIONS Specification Min. Typ. Max. Unit Accuracy (overall error) * 0.1 % (±1 count) Linearity ±1 count Sample rate 2.5 samples/sec Operating temperature range 0 50 °C Temperature stability 50 ppm/°C Supply voltage V+ to GND configuration 3 5 7.5 V d.c. V+ to V- configuration 6 9 15 V d.c. Supply current V+ to GND configuration 500 A V+ to V- configuration 350 A Backlight supply voltage 4.75 5.0 ** V d.c. Backlight supply current @ 5V d.c. 3050 *** mA Input leakage current (Vin = 0V) 1 10 pA * To ensure maximum accuracy, re-calibrate periodically. ** An external series resistor is required above 5V, see Applications. *** This specification linearly derates to 30mA @ 50°C. SAFETY Tocomply with the Low VoltageDirective (LVD 93/68/EEC), input voltages to the module’s pins must not exceed 60Vdc. The user must ensure that the incorporation of the panel meter into the user’s equipment conforms to the relevant sections of BS EN 61010 (Safety Requirements for Electrical Equipment for Measuring, Control and Laboratory Use).

LASCAR ELECTRONICS LTD. LASCAR ELECTRONICS INC. LASCAR ELECTRONICS (HK) LIMITED MODULE HOUSE 3750 West 26th Street FLAT C, 5/FL., LUCKY FTY. BLDG. WHITEPARISH Erie 63-65 HUNG TO ROAD WILTSHIRE SP5 2SJ PA 16506 KWUN TONG KOWLOON UK USA HONG KONG TEL: +44 (1794) 884567 TEL: +1 (814) 835 0621 TEL: +852 2797 3219 FAX: +44 (1794) 884616 FAX: +1 (814) 838 8141 FAX: +852 2343 6187 E-mail: [email protected] E-mail: [email protected] E-mail: [email protected]

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DIMENSIONS All dimensions in mm (inches)

53.0 (2.17) 1.6 (0.06) Panel thickness: 1.0 - 3.0 2.8 (0.11) dia (0.04 - 0.12) 46.7 (1.84) 6.1 (0.24)

6.5 (0.26) 30 (1.18) 17.7 (0.7) 25.0 (0.98) 34.5 (1.36)

6.1 9.5 60 (2.36) (0.24) (0.37)

64.5 (2.54) 1.6 (0.06) Panel cut-out: 62.0 - 32.0 (2.44 - 1.26)

PANEL FITTING

Insulating Shake-proof Washer Washer

1 2 3

FUNCTIONAL BLOCK DIAGRAM PIN CONFIGURATION (rear view)

V+ V m A °F °C M k Ohm Hz : ~ Vref

CAL LCOM COM Rb Ra La BL- CAL 1 10 6.3

V+ GND BL- INHI INLO DP1 DP2 DP3 V- COM (0.25) INHI + A/D _ 1 8 2.54 18.6 (0.73) INLO (0.1)

V- GND DP321

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CIRCUIT DIAGRAM

XDP

LCOM

2 LCD 600

BC847

V+

3 XDP 9

6 7 BC847 8

PIN FUNCTIONS 1. V+ Positivepower supply to the meter and LED backlighting. 2. GND 0V power supply to the meter. 3. BL- Negative power supply connection to the LED backlighting. 4. INHI Positivemeasuring input. 5. INLO Negative measuring input. 6. DP1 Connect to V+ to display DP1 (199.9). 7. DP2 Connect to V+ to display DP2 (19.99). 8. DP3 Connect to V+ to display DP3 (1.999). 9. V- Negative power supply to the meter. 10. COM Ground for analogue section of A/D converter. It is actively held at 3.05V (nom.) below V+ and must not be allowed to sink excessive current (>100 A) by,for instance, connecting to a higher voltage.

Note: A negative supply is generated internally and mirrors the positive supply. For example: if V+ is +5V, then the internally generated V- is -5V. When measuring with the input referenced to the same supply rail as that of the panel meter,then the limitations on the input range are (V- + 1.5V) to (V+ - 1.5V).

SOLDER LINKS LCOM Normally Open. When soldered, connects COM to INLO. La Normally Closed. Short circuits the scaling resistor Ra.

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SCALING Two resistors Ra and Rb FSR Ra Rb may be used to alter the 2V 910k 100k Ra 4 full scale reading (FSR) of Voltage 20V 1M 10k + INHI the meter - see table. The Vin 200V 1M 1k meter will have to be re- 2000V* 1M 100R Vin orI in Rb 200 A 0R 1k calibrated by adjusting the 5 calibration potentiometer Current 2mA 0R 100R - INLO Iin 20mA 0R 10R on the rear of the module. 200mA 0R 1R *Ensure that Ra is rated for high voltage use.

APPLICATIONS Do not connect more than one meter to the same power supply if the meters cannot use the same signal ground. Takingany input beyond the power supply rails will damage the meter.

3.0 to 7.5V Meter Power Supply

+3.0 to +7.5V +3.0 to +7.5V +3.0 to +7.5V 11 1 V+ V+ V+ 4 44 + INHI + INHI I+ INHI 3 33 BL- ±200mV BL- Rb BL- ±200mV SBL - 5 SBL 5 SBL 5 INLO I- INLO - INLO

R=BL V+-5V R=BL V+-5V R=BL V+-5V GND 30mA GND 30mA GND 30mA 22 2 0V 0V 0V

Measuring a single ended input voltage Measuring an input voltage referenced to a Measuring a current from a circuit which is referenced to supply, i.e. the input floating supply, i.e. the input voltage and the floating with respect to the DPM's supply, voltage and the meter's power supply meter's power supply are isolated from each i.e. the current and the meter's power share the same 0V rail. Ensure solder other. Ensure solder link LCOM is closed. supply are isolated from each other. Ensure link LCOM is open. solder link LCOM is closed.

6.0 to 15.0V Meter Power +3.0 to +7.5V +6.0 to +15.0V +6.0 to +15.0V 1 1 1 V+ V+ V+ + 4 + 4 4 INHI INHI I+ INHI R=BL V+-5V 3 3 3 30mA BL- ±200mV BL- Rb BL- ±200mV S 5 S 5 S BL - INLO BL I- INLO BL - 5 INLO

R=V+-V--5V R=V+-5V BL BL RBL V- 30mA V- 30mA V- 9 9 9 -3.0 to -7.5V 0V 0V

Measuring a single ended input voltage Measuring an input voltage referenced to a Measuring a current from a circuit which is referenced to a split supply, i.e. the input floating supply, i.e. the input voltage and floating with respect to the DPM's supply, voltage and the meter's power supply the meter's power supply are isolated from i.e. the current and the meter's power share the same 0V rail. Ensure solder link each other. Ensure solder link LCOM is supply are isolated from each other. Ensure LCOM is open. closed. solder link LCOM is closed.

Specifications liable to change without prior warning DPM 750S-BL Issue 1 August/2002 M.C. Applies to DPM 750S-BL/2

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