® ® NEW DESIGN! Wider Operating Range 1500V Isolation, Easier To Modify DMS-EB-AC/DC 100-264Vac Power Supply Accessory Board for DMS-30PC/LCD Panel Meters Order on-line at www.datel.com This low-cost accessory board provides an easy way of powering all DMS30PC-X-RL (red low-power models only), as well as all DMS-30LCD and DMS40LCD (non-backlit, +5V-powered models only) panel meters from 100-264Vac (50/60Hz). The on-board AC/DC converter provides an isolated +5Vdc to power the meter’s electronics, while providing 1500Vac isolation between the AC supply and the input signal being measured. Line power and input signals connect to two rugged, screw-style terminal blocks (TB1 & TB2) permanently mounted on the DMS-EB-AC/DC. This type of terminal block provides reliable mechanical connections and eliminates the need for any extra wiring harness connectors. Features ? Allows meters to operate from 100 to 240Vac (50/60Hz) ? Screw-type terminal block connections ? Provides 1500V isolation between AC supply and input signal ? Has prototyping features of the standard DMS-EB board ? On-board solder gaps for decimal point placement ? Same size as DMS-30/40 meters 2.02" (51.3mm)L x 0.82" (20.8mm)W ? Low cost (–) INPUT LO 12 +VIN SG14 (+) INPUT HI The DMS-EB-AC/DC board includes provisions for installing several usersupplied components that are required when the meter must be scaled to display non-standard input ranges. The DMS-EB-AC/DC has provisions for such common applications as attenuation of high input voltages, gain (span) and offset (zero) adjustments, and direct decimal point placement. The DMS-EB-AC/DC is compatible with all four input versions of the DMS-30 Series meters (±200mV, ±2V, ±20V and ±200V). Solder gaps, conveniently placed on the board, are easily bridged or cut to configure the board to meet each application’s specific requirements. SG10 R2 ➁ 1 +VOUT DC/DC CONVERTER 11 –VIN +5V SUPPLY 2 –VOUT R1➁ ANALOG COMMON 10 SG9 R3 10.5k R4 2k ➂ 3 SG7 + +1.23V REF. OUT 9 8 SG13 SG8 SG3 4 SG6 SG11 R5 ➂ 5V RETURN DP 3 SG2 5 REF. OUT/DP4 50k DP 2 SG1 SG4 REF. IN 6 DP 1 7 SG12 ➀ Refer to Mechanical Layout drawing for components and solder gap location. ➁ Components are user-supplied and not part of the standard product. ➂ R4 and R5 are part of the resistor accessory kit RN-DMS (see ordering information) ➃ SG5 is not used Open solder gap TB1 TB2 1 HI (+) 2 LO (–) 1 AC LO Closed solder gap 2 AC HI Figure 1. DMS-EB-AC/DC Simplified Schematic Diagram DATEL, Inc., Mansfield, MA02048 (USA) ? Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 ??? Email:[email protected] ?? Internet: www.datel.com DMS-EB-AC/DC 100-264Vac POWER SUPPLY BOARD FOR DMS-30 METERS ensure that modifications, if any, have been correctly made and that all cut solder-gaps are fully open. Align pin 1 of the meter with pin 1 of the DMS-EB-AC/DC, slide the board down flush to the meter’s housing and solder all 12 pins. Lastly, carefully cut the meter’s 12 pins as close as possible to the pc-board surface. Functional Specifications (TA = +25°C) AC Supply Voltage: 100 to 264Vac @ 47-68Hz AC Supply Current @ 264Vac/60Hz 60mA, maximum Making absolutely sure that the AC supply is de-energized (OFF), connect the AC supply to TB2 terminals 1 (AC LO) and 2 (AC HI). Connect the input signal being measured to TB1 terminals 1 (+HI) and 2 (-LO). Isolation 1500Vac, minimum Operating Temperature Range 0 to +60° C 2. Grounding/Isolation: Because DMS-30 and DMS-40 meters are housed in a plastic case, a connection to AC earth ground is not required. When wired per the instructions above, the DMS-EB-AC/DC board provides a minimum of 1500V isolation between its AC supply input (TB2) and its input signal (TB1). However, please keep in mind that in many applications the LO side of the input signal may be connected to AC ground (i.e., earth ground) elsewhere in the system. Any Issues pertaining to grounding and/or isolation of the DMS-EB-AC/DC power supply board must be referred to qualified technical personnel. Storage Temperature range –25 to +75° C Humidity 0 to 95%, non-condensing Dimensions 2.02" (51.31mm)L x 0.82" (20.8mm)W x 0.60" (15.3mm)D TB1 and TB2 Wire Size and Strip Length Wire Size 16 to 22 AWG (solid or stranded) Strip Length 0.25" (6.35mm) Screw Torque 3.6 pound-inches (0.4Nm) Rated Voltage 310Vac 3. Input Resistor Dividers (See Figure 4): Use 1%, or better, metal film resistors for R1 and R2 in DMS-30 applications, and 0.5%, or better, in DMS-40LCD applications. Make sure the resistor’s power and voltage ratings are adequate for the given application. Using tight-tolerance resistors in input scaling circuits allows most calibration adjustments to be made with the meter’s internal rear-mounted potentiometers, through the access holes provided (see Technical Note 5 below). Ordering Information DMS-EB-AC/DC RN-DMS AC power supply board Resistor accessory kit for DMS-30 meters 4. DMS-40LCD Meters: The RN-DMS resistor accessory kit, comprised of potentiometers R4 (Gain/Span) and R5 (Offset/Zero), cannot be used with DMS-40LCD Series meters. However, to change the input range on DMS-40LCD meters from the default low-range (i.e., with pin 2 of the meter open) to the high range, short pin 2 to pin 1 (+5V) on the top right side of DMS-EB-AC/DC board (refer to Figure 2 and the DMS-40LCD data sheet for more information). Introduction As shipped, the DMS-EB-AC/DC is configured for use with +5V-powered DMS-30PC or DMS-30LCD 3½ digit meters using the meter’s internal reference (SG13 is closed). This configuration is the most common and works well for most simple voltage measurements. Please read all of the following technical notes and perform any required modifications before soldering the DMS-EB-AC/DC onto the host meter. 5. Calibration Potentiometer Adjustment Holes: Two overlapping holes on the DMS-EB-AC/DC provide access to the built-in ¾-turn calibration potentiometer on DMS-30 meters or the 3-turn potentiometer on DMS40LCD meters. The adjustment range of both pots is very narrow. See the applicable product data sheet for more information on each meter’s calibration potentiometers. Many of the applications described below apply to both DMS-30 (3½ digit resolution) and DMS-40 (4½ digit resolution) meters. However, Application 5, installing the span (R4) and offset (R5) adjust potentiometers, can only be used with DMS-30PC/LCD meters. Also note that some of the other applications require the installation of R4 and R5. See Technical Note 4 when using the DMS-EB-AC/DC with DMS-40LCD meters. 6. Solder Gap Identification (See Figure 2): Each solder gap’s respective number is printed directly on the pc-board surface in copper etch. Be sure to double check all solder gap modifications before applying ac power and the input signal to the DMS-EB-AC/DC. !IMPORTANT! AC power must be disconnected from TB2 terminals 1 and 2 before making modifications or installing user-supplied components on the DMS-EB-AC/DC board! In many applications, the DMS-EB-AC/DC installation is subject to electrical-code requirements (for example, the NEC in the USA). Fusing, grounding, wire gauges, and leakage currents may be regulated items. Since the DMS-EB-AC/DC is a lineoperated device, it presents a shock hazard and should be installed only by qualified personnel. Do not hesitate to contact DATEL if you have any questions. Technical Notes 7. AC Supply Transients: The DMS-EB-AC/DC can withstand transients typically found in instrumentation environments. Installations which contain ac-powered equipment capable of generating large voltage and/or current surges should use external energy-clamping devices. A 1500 Watt bi-directional transzorb with a minimum stand-off voltage rating that matches the highest line-voltage peaks will provide additional protection under severe fault conditions. If a transzorb or other energy limiting device is used, the ac supply feeding the DMS-EB-AC/DC should have its own fuse. Refer to the fusing section for more information. 1. Soldering and Wiring: DATEL recommends the use of “no-clean” solders when installing components or making modifications to the DMSEB-AC/DC. Before mating the DMS-EB-AC/DC to the host meter, 8. AC Supply Fusing: The DMS-EB-AC/DC board does not have an internal fusing device. If required, a 0.2A slow-acting fuse is recommended. Be sure the fuse is rated for the applied line voltage. 2 DMS-EB-AC/DC 100-264Vac POWER SUPPLY BOARD FOR DMS-30 METERS SG10 12 1 SG14 SG7 SG8 DP4 SG6 TB2 TB1 SG4 SG13 SG12 SG3 (DP3) SG11 SG2 (DP2) R3 SG1 (DP1) SG9 1 HI(+) 2 1 2 LO(–) AC LO AC HI Figure 2. DMS-EB-AC/DC Board Applications Potentiometer R5 applies a stable, positive dc-offset voltage to the meter’s IN LO terminal. This offset voltage has a range of 0 to +1.2Vdc, measured with respect to TB1 terminal 2 (LO). It can be used to null (or cancel) the effects of an input whose zero level is not exactly zero volts. For example, adjusting R5 allows the display to read “000” with an input whose lowest level is slightly above zero volts. Please note, R5 can not compensate for inputs whose zero level is negative (i.e., if TB1 HI is more negative than TB1 LO). 1. Decimal Point Placement: DATEL ships the DMS-EB-AC/DC with all decimal point solder gaps (SG1, SG2, SG3 and SG4) open. To enable a specific decimal point, close its respective solder gap with solder. When reassigning decimal places for subsequent applications, remember to open any previously closed solder gaps. Close SG1 for 1.999 (DP1) Close SG2 for 19.99 (DP2) Close SG3 for 199.9 (DP3) Close SG4 for 1999.9 (DP4 on DMS-40LCD) 3. Measuring Input Voltages Greater than 1.999Vdc (Use DMS-30-0 or DMS-30-1 Only): If possible, the resistors used for R1 and R2 should be ±1% metal-film types with TCR’s less than or equal to 100ppm/°C. More information on selecting 1% resistors can be found in Application Note 14 of the DATEL Panel Meter Catalog. 2. Span (Gain) and Zero (Offset) Adjustments (See Figure 3): DATEL offers a resistor accessory kit, part number RN-DMS, consisting of 20turn potentiometers R4 (2K Ohms) and R5 (50K Ohms) and leaded resistor R3 (10.5K Ohms). However, the leaded resistor supplied with the RN-DMS accessory kit is not needed with the DMS-EB-AC/DC since it contains a factory-installed 10.5K Ohm chip resistor. Once installed, these potentiometers permit the span and/or zero adjustments described in the following sections. R4 provides span adjust, while R5 applies a positive offset to the meter’s (–) IN LO input. CAUTION: Do not apply inputs greater than +/-250Vdc. 1. Open SG10. For applications in which input voltages exceed ±100Vdc, also cut the 2 adjoining traces. 2. Configure the DMS-EB-AC/DC for span adjust using the procedure previously outlined. 3. Calculate values for R1 and R2 as follows: A typical value for R1 is 1M? . The sum of R1 + R2 should be between 50k? and 10M? . Using Potentiometer R4 for Span Adjustment (DMS-30PC and DMS30LCD Meters Only) R2 = (FSI x R1) / ( |Vin| - FSI) Where: FSI = The attenuated voltage between the meter’s (–) IN LO and (+) IN HI pins (pins 12 and 11, respectively) needed to achieve the desired display readings Vin = Input signal at TB1 terminals 1 and 2, disregarding polarity 1. For DMS-30-1, -2, and -3 models (+/-2V, +/-20V, +/-200V ranges): Configuring the DMS-EB-AC/DC for span adjustment is simply a matter of installing potentiometer R4, opening SG13, and then closing SG8, SG11, and SG12. 2. For DMS-30-0 models (+/-200mV ranges): Span adjustment requires that you open SG8, SG11 (if closed) and SG13 and then close SG7, SG9 and SG12. Then install R4. Example Using a DMS-30-1 meter (+/-2V range), Vin is 0-5Vdc and the display reading must be “000” to “1500” Adjust span as desired. DMS-30-1, -2, and -3 span adjustment range is typically +10% and –5%. The DMS-30-0 has a much wider span adjust, however, it should be limited to ±10% for optimum accuracy and stability. 1. Assume R1 = 1.0M? . Using Potentiometer R5 to Apply a Positive Offset to Pin 12 (-) IN LO 2. R2 = (FSI x R1) / ( |Vin| - FSI) R2 = (1.500 x 1,000,000) / (5.0 - 1.500) R2 = 428,571? or 432k? 1. Open SG14 and close SG6. 2. Install 50K potentiometer R5. 3. Calibrate the meter using a known voltage source. Adjust R4 to compensate for tolerances in R1 and R2. 3 DMS-EB-AC/DC 100-264Vac POWER SUPPLY BOARD FOR DMS-30 METERS Applications 4. DC Current Measurements (Use +/-200mV Range DMS-30-0 Meters): When using R2 location for a dc current-shunt, please note that the pcboard copper traces which short out R1 can only carry currents up to 0.2A (200mA). However, dc currents up to 2A can be accommodated if a 20AWG jumper wire is soldered in location R1. Be sure R2 has a sufficient power rating to safely carry the full load current. Refer to DMS Application Note 6 for more information on dc ammeters. 1. Install R2: R2 = FSR / (I MAX . x 10000) where FSR is the desired meter reading (0 up to 1999, disregarding any decimal points), and IMAX is current in Amperes. 3. Apply the input signal (current) to TB1 (+) HI and (–) LO. 4. Adjust R4 for desired full scale readings. 5. Enable the appropriate decimal point using SG1, SG2, or SG3. Example Using a DMS-30-0 meter, a 0.100 Ampere input must read “100.0” mA on the display. R2 = 1000 / (0.1 x 10000) R2 = 1 Ohm Enable DP3 via SG3 for a display reading of “100.0”. 2. Configure the DMS-EB for span adjust using the procedure previously outlined for the DMS-30-0 (+/-200mV range). R1 12 SG10 12 R2 R5 SG14 SG14 SG7 SG8 SG6 SG7 SG8 TB1 SG13 R4 SG11 TB1 SG11 SG13 R3 SG12 SG9 R3 SG12 1 SG9 1 2 HI(+) HI(+) LO(–) Figure 3. R4 and R5 Installation ® SG6 SG4 DP4 SG4 DP4 2 LO(–) Figure 4. R1 and R2 Installation ® ISO 9001 REGISTERED www.datel.com DS-0341B DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 Internet: www.datel.com Email: [email protected] 09/02 DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01 DATEL GmbH München, Germany Tel: 89-544334-0 DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025 DATEL 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. The DATEL logo is a registered DATEL, Inc. trademark.