DMS-EB www.murata-ps.com Multi-Purpose Application Board for DMS-30 & DMS-40 Series Meters FEATURES „„ Accommodates 3½ and 4½ digit meters „„ Gain (span) and offset (zero) adjustments for PRODUCT OVERVIEW DMS-30 meters The DMS-EB Application Board covers many common panel meter applications while providing „„ Input divider network for high voltages simple signal and power I/O terminations (via a standard MOLEX connector) for Murata Power Solutions' „„ Operate meter and board from +5V supply or DMS-30 and DMS-40 Series, LED/LCD Display, Digital Panel Voltmeters. The unique plug-and-play design 9/12V battery of the DMS-EB makes changing from application to application and meter to meter quick, easy and inexpensive. „„ Solder gaps for decimal placement The highly versatile DMS-EB has provisions for such common applications as attenuation of high „„ Same size as DMS-30/40 Series meters input voltages, gain (span) and offset (zero) adjustments, 9/12V battery operation, and direct decimal „„ 2.02" (51.31mm)L x 0.83" (21.08mm)W point placement. The DMS-EB is compatible with all four versions of the DMS-30 and DMS-40 Series (±200mV, ±2V, ±20V and ±200V) making it interchangeable from meter to meter and application to application. Solder gaps conveniently placed on the board are easily bridged or cut configuring the board to meet each application's specific requirements. This low-cost addition to Murata Power Solutions' expanding line of miniature meters is evidence of our continuing commitment to offer the most versatile, easy-to-use, panel meter products. SIMPLIFIED SCHEMATIC            NOTES:  Components are user-supplied and not part of the standard product.  For DMS-40 meters only. Figure 1. DMS-EB Schematic Diagram for DMS-30 Meters For full details go to www.murata-ps.com/rohs www.murata-ps.com/support MPM_DMS-EB.C02 Page 1 of 4 DMS-EB Multi-Purpose Application Board for DMS-30 & DMS-40 Series Meters Close SG6 when measuring floating inputs with a 9V-powered meter Ordering Information (floating inputs are described in Technical Note 7). SG6 provides a bias reference for the input signal by tying LO to the meter's Analog Com- DMS-EB-C Application board with mating connector mon terminal (pin 10). and terminals DMS-BZL1-C DMS-30/40 bezel assembly 3. Input Resistor Dividers: Use 1%, or better, metal film resistors for DMS-BZL2-C DMS-30/40 bezel assembly with R1 and R2 in DMS-30 applications, and 0.5%, or better, in DMS-40 sealing gasket applications. Using tight-tolerance resistors in input divider networks allows most final calibration adjustments to be made with the meter's See www.murata-ps.com/dpm-availability for model-specific availability. rear calibration pots through the access holes provided. Make sure Functional Specifications the resistor power and voltage ratings are adequate for the given (Ta = +25°C) application. Input Supply Range See applicable meter's data sheet 4. Using U1 (LM7805CT): The power supply voltage range listed in the Input Supply Range U1 (LM7805CT) Installed: Battery Operation section is rated for a 150mA LED meter or a 35mA DMS-30/40PC-X-XS +7.5 to +12.6V backlit LCD meter. A 10μF/35V tantalum capacitor (C2) should be DMS-30/40PC-X-XL +7.5 to +18.0V DMS-30/40LCD-X-5 +7.5 to +32.0V installed with the polarized end next to the + symbol on the DMS-EB. DMS-30/40LCD-X-5B +7.5 to +12.6V This is especially important if the power supply is located far from U1. Operating and Storage Temperature See applicable meter's data sheet 5. DMS-40 Meters: When the DMS-EB is used with DMS-40PC or DMS- Humidity 0 to 95%, non-condensing 40LCD meters, be sure to open SG13. The RN-DMS resistor acces- Dimensions 2.02" (51.31mm)L x 0.83" (21.08mm)W sory kit comprised of resistor R3 and potentiometers R4 (Gain/Span) J1 Connector & Wire Information and R5 (Offset/Zero), cannot be used with DMS-40 series meters. To Terminal Type MPS P/N 4400-01032-0 change the input range on DMS-40LCD meters from the low range to Crimp Tool MPS P/N 39-2099000 Wire Size 22 to 26 AWG the high range, close SG16. Insulation Diameter 0.062" (1.57mm) max. 6. Calibration Potentiometer Adjustment Holes: Two overlapping Stripping Length 0.100" to 0.125" (2.54 to 3.17mm) holes on the DMS-EB provide access to the ¾-turn calibration poten- tiometer on DMS-30 meters and the 3-turn potentiometer on DMS-40 Introduction meters. The adjustment range of both pots is very narrow. See the applicable product data sheet for more information on each meter’s As shipped, the DMS-EB is configured for 5V-powered DMS-30 3½ calibration potentiometers. digit meters operating in the single-ended mode (SG5 closed) using the meter's internal reference (SG13 closed). This configuration is the most 7. Input Configurations: The DMS-EB is supplied with SG5 closed. SG5 common and works well for most simple voltage measurements. connects J1, pin 2 (LO) to power return J1, pin 6 (GND) and configures Many of the applications described below apply to both DMS-30 the meter for single-ended operation, that is, the low side of the input and DMS-40 meters. However, Application 5, installing the span (R4) and is at system ground or zero Volts. SG5 must also be closed when offset (R5) adjust potentiometers, can only be used with DMS-30 meters. measuring floating inputs. Floating inputs are signals which have no Also note that some of the other applications require the installation of electrical connection, or reference to, the power supply which powers R4 and R5. See Technical Note 5 when using the DMS-EB with DMS-40 the meter. meters. In applications in which input LO is connected to ground elsewhere in Please read all of the following technical notes and perform any the system, and SG5 is closed, unwanted ground-loop induced display required modifications before soldering the DMS-EB onto the meter errors may develop. Ground loops, a condition in which display drive (aligning pin 1 to pin 1). After soldering, carefully connect +5Vdc to +V currents also flow through the input signal wiring, can cause unstable (J1, pin 5) and power return to –V (J1, pin 6). display readings. If this occurs, try opening SG5 to see if the display stabilizes. TECHNICAL NOTES SG5 must be open when measuring differential inputs that are refer- 1. LCD Backlighting: For DMS-30LCD backlit models, close SG15. For enced to the same supply which powers the meter. DMS Application DMS-40LCD backlit models close SG18. See the DMS-30LCD or the Note 2 (Input Configurations, Power Supplies and Ground Loops) DMS-40LCD data sheets for limitations on backlighting 9V-powered provides a detailed discussion of input configurations. meters. 8. Soldering: Murata Power Solutions recommends the use of "no- 2. 9V-Powered, LCD Display Models: DMS-30LCD-X-9 and DMS- clean" solders when installing or making modifications to the DMS-EB. 40LCD-X/X-9 meters cannot be used in single-ended input configura- tions, i.e., LO (J1, pin 2) cannot be connected to GND (J1, pin 6). When operating from a 7.5 to 14Vdc power source with a single-ended input, use a +5V-powered meter and install U1 (see Battery Operation section and Technical Note 4). www.murata-ps.com/support MPM_DMS-EB.C02 Page 2 of 4 DMS-EB Multi-Purpose Application Board for DMS-30 & DMS-40 Series Meters APPLICATIONS 1. Decimal Point Placement: Murata Power Solutions ships the DMS- Using Full Range Span Adjustment (DMS-30 Only) EB with all decimal point solder gaps (SG1, SG2, SG3 and SG17) open. 5.1. For DMS-30-1 and -2 models: Configuring the DMS-EB for span To enable a specific decimal point, close its respective solder gap with adjustment is simply a matter of installing resistor R3 and potenti- solder. When reassigning decimal places for subsequent applications, ometer R4, opening SG13 and then closing SG8, SG11 and SG12. remember to open previously closed solder gaps. 5.2. For DMS-30-0 models: Span adjustment requires that you open Close SG1 for 1.999 (DP1) SG8, SG11 (if closed) and SG13 and then close SG7, SG9 and Close SG2 for 19.99 (DP2) SG12. Then install R3 and R4. Close SG3 for 199.9 (DP3) Adjust span as desired. DMS-30-1 and -2 span adjustment range Close SG17 for 1999.9 (DP4 on DMS-40) is typically +10% and –5%. The DMS-30-0 has a much wider span 2. Display Test: Tie J1, pin 4 (TEST OUT) to pin 3 (TEST IN) to test the adjust, however, it should be limited to ±10% for optimum accuracy. display of the DMS-30. Do not leave the meter in the test mode for 6. Measuring Input Voltages Greater than 1.999Vdc (Use DMS-30-1 more than 10 seconds. Display test is not available on backlit models. Only): If possible, the resistors used for R1 and R2 should be ±1% 3. Battery Operation: Open SG4 and install U1 (LM7805CT) with its metal-film types with TCR's less than 100ppm/°C. More information metal tab facing down as shown Figure 2. Allowable input power on selecting 1% resistors can be found in Application Note 14. ranges (J1, pins 5 and 6) are as follows: CAUTION: Do not exceed 250Vdc input signals. DMS-30/40PC-X-XS +7.5 to +12.6V 6.1. Open SG10. For applications in which input voltages exceed DMS-30/40PC-X-XL +7.5 to +18.0V ±100Vdc, also cut the 2 adjoining traces. DMS-30/40LCD-X-5 +7.5 to +32.0V DMS-30/40LCD-X-5B +7.5 to +12.6V 6.2. Configure the DMS-EB for span adjust using the procedure revi- ously outlined for the DMS-30-1 version. 6.3. Calculate values for R1 and R2 as follows: U1 Metal tab R1 points down SG10 SG3 SG2 SG1 xx.xx xxx.x x.xxx To measure input voltages greater than ±100Vdc, Figure 2. Installing U1 open SG10 and also cut these two etch paths. 4. Differential Input Signals (Signal Referenced to Power Source): Figure 3. Installing R1 Open SG5. Apply the input signal to pin 1, (+) IN HI, and pin 2, (–) IN LO, of J1. A typical value for R1 is 1MΩ. The sum of R1 + R2 should be between 50kΩ and 10MΩ. Note: Common mode voltage must not exceed ±2Vdc. Differential signals are defined as inputs whose two terminals are both above and R2 = (FSI x R1) / ( |Vin| - FSI) below J1, pin 6 (GROUND). Where: 5. Span (Gain) and Zero (Offset) Adjustments: Locations are included FSI = The attenuated voltage, between the meter's (–) IN LO and on the DMS-EB to add user-supplied potentiometers R4 and R5, and (+) IN HI pins, needed to achieve the desired display readings resistor R3. Recommended values for these components are as fol- lows: R3: 10.5KΩ, 1%, 1/8W metal film; R4: 2KΩ, 10-20-turns; R5: Vin = Input voltage at J1 (between pins 1 and 2) 50KΩ, 10-20 turns. Vishay's T93YA series potentiometers are suitable for this application. Make sure to use only RoHS-compliant compo- nents and solders when making modifications to DMS-EB. Once installed, these components permit the span and zero adjust- ments described in the following sections. R3 and R4 provide span adjust, while R5 applies and offset voltage to (-) IN LO (J1, pin 2). www.murata-ps.com/support MPM_DMS-EB.C02 Page 3 of 4 DMS-EB Multi-Purpose Application Board for DMS-30 & DMS-40 Series Meters APPLICATIONS 7.1. Install R2: R2 = FSR / (Imax. x 10000) where FSR is the desired Example meter reading (0 -1999) and Imax is between 0 -1 Ampere. Vin is 0-5Vdc, and the display reading must be "000" to "1500." 7.2. Open SG5. 1. Assume R1 = 1.0MΩ. 7.3. Configure the DMS-EB for span adjust using the procedure previ- 2. R2 = (FSI x R1) / ( |Vin| - FSI) ously outlined for the DMS-30-0 version. R2 = (1.500 x 1,000,000) / (5.0 - 1.500) 7.4. Apply input signal (current) to (+) IN HI and (–) IN LO. R2 = 428,571Ω or 432kΩ 7.5. Adjust R4 for desired full scale readings. 3. Calibrate the meter using a known voltage source. Adjust R4 to compensate for variations in R1 and R2. 7.6. Enable the appropriate decimal point using either SG1, SG2, SG3 or SG-17. 7. Current Measurements (Use 200mV Model, DMS-30-0): The follow- ing instructions are for measuring current derived from the DMS- Example 30/40's power source. When measuring current that is floating with respect to J1, pin 6 (POWER RETURN), leave SG5 closed. A 0.100 Ampere input must read "100.0" on the display. CAUTION: Do not exceed 1 Ampere input current R2 = 1000 / (0.1 x 10000) R2 = 1 Ohm Enable DP3 via SG3 for a reading of "100.0." HI LO TST TST +V –V (+) (–) IN OUT GND Figure 4. DMS-EB Board 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-EB.C02 Page 4 of 4