POL/AC V+ V- V/ COM mA/ A mA H -DC/ V/ /A L-~ mA HOLD BEEP LED- LED+ Vp+ Vp- mA/ A K/m /A BAT/V DMM 939 3� Digit LCD Autoranging Multimeter This module is a complete multimeter in a panel instrument. It is especially useful in portable equipment and has 12 ranges: D.C. - 400mV, 4V, 40V and 400V (Maximum IP –375V) D.C. - 4000mA, 40mA, 400mA, 4A, Resistance - 4kWW , 40k , 400kWandW4M . 15mm (0.6�)Digit Height M - + Digital Hold k Autoranging uA mAV Low Battery Indication LED Backlighting D.C. Supply Isolator Continuity Beeper Output Stock Number Standard Meter DMM 939 METER PROTECTION Specification Min. Typ. Max. Unit The meter should be protected against accidental application Accuracy D.C. volts 400V –2 % Rd g–1 count of high voltages on ohms and current ranges by a fast-blow D.C. volts all other –0.3 % Rdg–1 count 5A fuse. Ohms 4 kilohms, 400 kilohms –0.75 % Rd g–8 counts Ohms 40 kilohms, 4 megohms –1 % Rd g–9 counts D.C. current adjusted –0.5 % Rd g–2 counts RECALIBRATING THE METER Linearity (best straight line) -1 +1 count Power the meter with its typical working voltage and make Rollover error –4 counts connections as follows: Operating temperature range 0 50 �C - Connect Pin 8 to Pin 1. Supply voltage (Vp+ to Vp-) 5 9 18 V - Apply -3.700 volts D.C. between V/W(Pin 3) and COM (Pin 4). Supply current (excluding backlight) 5 7 13 mA - Adjust R4 until meter displays -3.700V. Continuity detect low ohm range 1.5 kilohms Converter isolation (D.C.) 40 V Backlight current (5V nom.) 50 90 mA LOW POWER OPERATION If ultra low power operation is required, then an isolated supply (battery) can be applied across V+ and V- to give this mode of operation. Note - Ensure that the supply does not exceed 11 volts. CONNECTOR SOURCING GUIDE Low Power Operation Min. Typ. Max. Unit METHOD Cable Mounting IDC Supplied With Product Supply voltage (V+ to V-) 7 9 11 V Supply current 1.5 2.4 mA Low battery threshold 6.5 7 7.5 V DIMENSIONS All dimensions in mm (inches) 61.5 (2.42) d e a. 1.0 (0.04) 51 (2.01) 51.0 (2.01) �5.7 b. 2.0 (0.08) (0.22) c. 6.5 (0.26) d. 11.5 (0.45) REAR VIEW e. 10.0 (0.39) W W OVERLOAD 19 1 When the meter displays 20W2WW"OL" this indicates that the mmeter inputs have been taken beyond their working range. �3.0 Display in "Overload" Panel cut-out 72 x 40 (2.83 x 1.57) (0.12) Maximum panel thickness 3mm (0.12). 76.0 (2.99) a 72.5 (2.85) W m ON BOARD SOLDER LINKS 1 REAR 19 1 VIEW 20 2 mA RES I 51.0 (2.01) b c 39.0 (1.54) 44.0 (1.73) 24.0 (0.94) 40.5 (1.59) 24.5 (0.96) 24.0 (0.94) 24 (0.94) LASCAR ELECTRONICS LTD. LASCAR ELECTRONICS INC. LASCAR ELECTRONICS (HK) LIMITED MODULE HOUSE, WHITEPARISH, 3750 West 26th Street, FLAT C, 5/FL., LUCKY FTY. bldg., 63-65 HUNG TO ROAD WILTSHIRE SP5 2SJ UK Erie, PA 16506 USA KWUN TONG, KOWLOON, HONG KONG TEL: +44 (0)1794 884567 FAX: +44 (0)1794 884616 TEL: +1 (814) 835 0621 FAX: +1 (814) 838 8141 TEL: +852 2797 3219 FAX: +852 2343 6187 E-mail: sales@lascar.co.uk E-mail: us-sales@lascarelectronics.com E-mail: b4lascar@samsongroup.com.hk PIN FUNCTIONS 1. V+ Positive power supply connection.Not isolated. Pins 1 and 2 are used for mode selection and low power operation. 2. V- Negative power supply connection. 3. V/WW Positive Volts measuring input. Connect to (Pin 10) to measure resistance. 4. COM Ground for analogue section of the A/D converter, it is held actively at 2.9V (typ.) below V+. COM must not be allowed to sink excessive current (>100mA) by connecting it directly to a higher voltage. 5. mA Positive milli-Amperes measuring input. Tri-State Input Connections 6. mA/mA Tri-state input, connect to V+ to display ’mA’ annunciator. Pin No. V+ OPEN or COM V- Connect to COM to display ’mm A’ annunciator. Note - mA/ A 6 mA mA Do not connect to V- annunciators will not be displayed unless Pin 7 is connected to V-. 7VWA 7. V/W/A Tri-state input, connect to COM to operate voltage range and to 8 HWW -DC L Do not connect to V- display ’V’ annunciator. Connect to V+ to operate Resistance range 11 HOLD AUTO Do not connect to V- and to display relevant ’W’ annunciator or connect to V- to display either mA ormA, selection between each of these annunicators is determined by Pin 6. 8. HW-DC/ Tri-state input, connect to V+ to select High Ohms and D.C. range input. Connect to COM for Low Ohms. LWAll the ranges will show the appropriate annunciator, MWW , k or ~ symbol. 9.mA Positive micro-Amperes measuring input. 10.WOhms measuring input. Connect to Pin 3 when measuring resistance. 11. HOLD Tri-state input, connect to V+ to hold display reading. 12. BEEP The continuity beeper output is designed to drive a piezo-electric transducer at approximately 2KHz with a voltage swing of V+ to V-. Note - The beeper output off state is at the V+ rail. 13. LED- Negative supply to LEDs for backlighting. LED+ to LED- supply voltage of 5V. 14. LED+ Positive supply to LEDs for backlighting. 15. Vp+ Positive isolated power supply connection. It is recommended that the meter is powered using these pins. 16. Vp- Negative isolated power supply connection. 17-20 No pins fitted. VARIOUS OPERATING MODES Piezo-electric 1 8 1 8 1 S2 N.C. Transducer 15 15 V+ 15 V+ 11 Vp+ V+ Vp+ Vp+ SUPPLY 8 HOLD HW-DC/ SUPPLY SUPPLY (5-18V) 16 16 LW(5-18V) Vp- 16 (5-18V) S2 Vp- S2 11 Vp- S3 N.C. + 11 9 HOLD HOLD 8mA HW-DC/ 3 V LWS5 A 5 3 mA S5 Resistance to be B Input Current V 7 6 10 placed acrossWV/W/A mA/mA to be measured Rs Input Voltage these terminals 12 V/W/A 7 0.1W* to be measured for measurement BEEP - 7 4 4 4 COM COM V/W/A COM 5A Quick V- 5A Quick Blow Fuse 2 Blow Fuse Autoranging Resistance Meter Autoranging D.C. Current Meter Autoranging Volt Meter Ranges: Low Ohm - 4kWW , 40k Ranges:mm A - 4000 A, 40mA High Ohm - 400kWW , 4M mA - 400mA, 4000mA *Note - Rs is the current sensing resistor and must be capable of handling as a minimum the full scale current of 4 amps. To allow for overload conditions, it is Piezoelectric 1 S1 Transducer S2 V+ 15 recommended that a 6W, 0.5% resistor is Vp+ 11 HOLD SUPPLY fitted. It must be fitted when EITHER of (5-18V) 16 S3 Vp- + 8 HW-D.C./ the current ranges are being used. V/WLW 3 V 12 10 S4 AWBEEP - CURRENT S4 B 7 9 V/W/AmA 5 SWITCHES S5 mA A *RS S5 B S1. Switch 1 is an on/off switch. COM 0.1W6 4 mA/mA COM V- S2. Switch 2 is used to hold the display reading. 5A Quick 2 Blow Fuse S3. In Voltage mode, switch 3 is used to select D.C. measurement and the ~ symbol. In Resistance mode, this switch is used to select either high or low ohms ranges. S4. Switch 4 selects either the Voltage, Current or Resistance ranges. Autoranging Voltage, Current and Resistance Meter S5. Switch 5 selects between Current ranges. *See note on Current Meter diagram. HEALTH AND SAFETY 1. When the DMM is used for current or resistance measurements, an external fuse MUST be fitted. 2. When measuring voltages in excess of 60V peak, the system within which the DMM is incorporated, should conform to relevant sections of IEC 1010 (Safety Requirements for Electrical Equipment for Measuring, Control and Laboratory Use). 3. If this product is to be used for measuring mains supply voltages, external transient protection should be adopted. 4. To comply with the Low Voltage Directive (LVD 93/68/EEC), input voltages to the module�s pins must not exceed 60Vdc, then fit scaling resistors externally to the module. The user must ensure that the incorporation of the DPM 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). Specifications liable to change without prior warning DMM 939 Issue 3 August/1997 M.C. Applies to DMM 939/5