DMS-EB2 www.murata-ps.com Multi-Purpose Application Board for DMS-20PC/LCD Meters The DMS-EB2 Application Board was designed for quick and easy application/evalu- FEATURES ation of Murata Power Solutions’ subminiature DMS-20PC/LCD Series, 3½ Digit, LED/LCD „„ Display, Digital Panel Voltmeters. The DMS-EB2's versatility, low cost and direct DMS- Gain (span) adjustment 20PC/LCD plug-in compatibility makes interfacing a breeze. The DMS-EB2 covers many „„ Input divider network for attenuating voltages common panel-meter applications while providing easy signal and power I/O terminations up to 250Vdc (via a standard MOLEX connector) and plug-in versatility when changing from one applica- „„ Operate meter and board from +5V supply or tion to another. 9/12V battery The DMS-EB2 has provisions for such common applications as input dividers for „„ high input voltages, gain (span) adjustment, 9/12Vdc battery operation, and decimal On-board solder gaps for decimal point placement point placement. The board permits direct signal I/O wiring via the interface connector or „„ On-board I/O connector for easy power and signal input soldering directly to the board. The DMS-EB2 is fully compatible with all four versions of the DMS-20PC/LCD (±200mV, ±2V, ±20V, ±200V) making it interchangeable from 12 1 R1 SG10 meter to meter and application to application. R2 Solder gaps are conveniently placed on the SG14 SG6 SG5 SG4 board and may be quickly bridged or cut as required. R5 C1 +C2 U1 This low-cost addition to Murata Power J1 Solutions’ expanding line of subminiature SG15 meters demonstrates our continuing commit- 12 34 56 J2 SG1 ment to offer the most versatile, easy-to-use panel-meter products.         For full details go to www.murata-ps.com/rohs Figure 1. DMS-EB2 Schematic Diagram www.murata-ps.com/support MPM_DMS-EB2.F02 Page 1 of 4 SG2 SG3 DMS-EB2 Multi-Purpose Application Board for DMS-20PC/LCD Meters age range can be extended up to 32Vdc. Functional Specifications (TA = 25°C) A 10µF/35V tantalum capacitor (C2 on schematic) should be installed Input Supply Range with the polarized end next to the + symbol on the DMS-EB2. This is See applicable meter's data sheet especially important if the power source is located far from U1. Input Supply Range U1 (LM7805CT) Installed: 5. Soldering: Murata Power Solutions recommends the use of "no-clean" DMS-20PC-X-XS +7.5 to +12.6V DMS-20PC-X-XL +7.5 to +32.0V DMS-20LCD-X-5 +7.5 to +32.0V APPLICATIONS DMS-20LCD-X-5B +7.5 to +12.6V Operating and Storage Temperature As shipped, the DMS-EB2 is configured for single-ended operation. See applicable meter's data sheet T his c onfigur a tion is pr ef er r ed f or simple v oltage measur emen ts and will generally cover most standard applications. Figure 1 indicates which Humidity 0 to 95%, non-condensing solder gaps are shipped closed from the factory. Dimensions 1.25" (31.8mm)L x 0.75" (19.1mm)H Simply solder the board onto the meter (pin 1 to pin 1), connect J1 Connector & Wire Information the power supply to J1, pin 5 (+V) and the power return to J1, pin 6 Terminal Type MPS P/N 39-2099090 (GROUND). Crimp Tool MPS P/N 39-2099000 Wire Size 22 to 26 AWG Insulation Diameter 0.062" (1.57mm) max. Pin Function Stripping Length 0.100" to 0.125" 1 (+) INPUT HI (2.54 to 3.17mm) J1 2 (–) INPUT LO 1 2 3 4 5 6 3 TEST/HOLD IN Ordering Information 4 TEST/HOLD OUT DMS-EB2-C Application board with mating connector and terminals 5 +V (Positive power connection) DMS-BZL3-C DMS-20 bezel assembly 6 –V (Ground, negative power return) DMS-BZL4-C DMS-20 bezel assembly with sealing gasket Figure 2. J1 Connector Pinout 4320-01074-0 6-position pc-board socket See www.murata-ps.com/dpm-availability for model-specific 1. Decimal Point Placement: Murata Power Solutions ships the availability. DMS-EB2 with all decimal point solder gaps (SG1, SG2 and SG3) open. To enable a specific decimal point, close its respec- TECHNICAL NOTES tive solder gap with solder. When re-assigning decimal places for subsequent applications, remember to unsolder previously 1. LCD Backlighting: To backlight a DMS-20LCD meter, connect J1, closed solder gaps. pin 3 (TEST/HOLD IN) to J1, pin 6 (GND). This allows for external Close SG1 for 1.999 (DP1) control, via a switch, of the backlight feature. The switch should Close SG2 for 19.99 (DP2) be rated for low voltage operation at 35mA. Close SG3 for 199.9 (DP3) 2. 9V LCD Meters: DMS-20LCD-X-9 meters cannot be used in a 2. Display Test (Not Available on LCD Models): Tie pin 4 (TEST/ single-ended configuration, i.e., with (–) IN LO tied to GND. On HOLD OUT) to pin 3 (TEST/HOLD IN) to test the display of the these models, both (–) IN LO and (+) IN HI have to be a minimum DMS-20PC. Do not leave the meter in the test mode for more of 1.5V above and 1.5V below J1 pins 6 and 5, respectively. To than 10 seconds. On LED meters with the HOLD option, tying operate from a 9V or 12V battery with (–) IN LO tied to GND, use pins 3 and 4 together freezes the display reading. a 5V-powered meter (DMS-20LCD-X-5), install U1 (LM7805CT) and open SG4. 3. Battery Operation: Open SG4 and install U1 (LM7805CT) with its metal tab facing to the left as shown in Figure 3. Allowable 3. Input Resistor Dividers: Always use 1%, or better, metal-film input power ranges (J1, pins 5 and 6) are as follows: resistors for R1 and R2, and also make sure their power and volt- age ratings are adequate for the given application. DMS-20PC-X-XS +7.5 to +12.6Vdc DMS-20PC-X-XL +7.5 to +32Vdc 4. Using U1 (LM7805CT): The input power range specified in the Battery Operation section is rated conservatively assuming a C2 (10µF/35V) can be added to reduce noise. Observe correct 100mA LED meter or a 35mA backlit LCD meter. If a non-backlit polarity. Refer to Technical Note 4 for more information. LCD model or the low-power LED model is used, the input volt- www.murata-ps.com/support MPM_DMS-EB2.F02 Page 2 of 4 DMS-EB2 Multi-Purpose Application Board for DMS-20PC/LCD Meters R1 12 SG10 1 R3 U1 TO-3-style tab points to left To measure input voltages greater than ±100Vdc, open SG10 and also cut these two etch paths. SG1 Figure 4. Installing R1 4. Calibrate the meter using a known voltage source. Adjust the internal Figure 3. Installing U1 gain potentiometer to compensate for variations in R1 and R2. Example 4. Calibration Adjustment: The DMS-EB2 has provisions for adjusting the calibration of the DMS-20 meter . Calibration adjustment is useful when VIN is 199.9Vdc, and the display reading must be "199.9". an input divider (using R1 and R2) is necessary to scale the input voltage. 1. Assume R1 = 1.0MΩ. The calibration potentiometer allows "tweaking" of the display reading. 2. R2 = (FSI x R1) / ( |VIN| - FSI) Using the calibration potentiometer R2 = (1.999 x 1,000,000) / (199.9 - 1.999) Adjust the calibration pot on the back of the meter as desired. The R2 = 10101.01Ω or 10kΩ adjustment range is only 3/4 of a turn. Do not force the pot past its end 7. Current Measurements (Use 200mV Model, DMS-20PC/LCD-0): The stops. following instructions are for measuring current derived from the DMS- 5. Differential Input Signals (Signal Referenced to Power Source): Open 20PC/L CD's power source. When measuring current that is floating with SG5. Apply the input signal to pin 1, (+) IN HI, and pin 2, (–) IN LO, of J1. respect to J1, pin 6 (GROUND), leave SG5 closed. NOTE: Common mode voltage must not exceed ±2Vdc. CAUTION: Do not exceed 1 Ampere input current. 6. Measuring Input Voltages Greater than 1.999Vdc (Use DMS-20PC/ 1. Install R2 (R2 = FSR / (IMAX x 10000)) where FSR is the LCD-1 Only): desired reading (0 -1999) and IMAX is between 0 -1 Ampere. CAUTION: Do not exceed 250Vdc input signal. 2. Open SG5. 1. Open SG10. F or applications in which input voltages exceed ±100V dc, 3. Apply input signal (current) to (+)IN HI and (–) IN LO. also cut the 2 adjoining traces. 4. Adjust internal gain pot for desired full scale readings. 2. Calculate values for R1 and R2 as follows: 5. Enable decimal points using either SG1, SG2 or SG3. R2 = (FSI x R1) / ( |VIN| - FSI) Example Where: A 1.0 Ampere input must read "1.000" on the display. FSI = The attenuated voltage, between the meter's (–) IN LO and (+) IN R2 = 1000 / (1 x 10000) HI pins, needed to achieve the desired display readings R2 = 0.1 Ohm VIN = Input voltage at J1 (beween pins 1 and 2) Enable DP1 via SG1 for reading of 1.000 A typical value for R1 is 1MΩ. The sum of R1 + R2 should be 8. Displaying DMS-20PC/LCD's Power Source between 50kΩ and 10MΩ. (Use DMS-20PC/LCD-2, 5V-Powered Models Only): 3. Enable DP3 by soldering SG3. 1. If the power source is higher than 5Vdc, be sure to install U1 and cut SG4. See Battery Operation section and Technical Note 4. 2. Solder a short piece of jumper wire across the two holes labeled J2. 3. Close SG2 to enable DP2. www.murata-ps.com/support MPM_DMS-EB2.F02 Page 3 of 4 SG2 SG3 DMS-EB2 Multi-Purpose Application Board for DMS-20PC/LCD Meters This product is subject to the following operating requirements Murata Power Solutions, Inc. and the Life and Safety Critical Application Sales Policy: ISO 9001 and 14001 REGISTERED Refer to: http://www.murata-ps.com/requirements/ Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. © 2018 Murata Power Solutions, Inc. www.murata-ps.com/support MPM_DMS-EB2.F02 Page 4 of 4