Model 1747 Dual Range DC Power Supply INSTRUCTION MANUAL
1 Safety Summary The following safety precautions apply to both operating and maintenance personnel and must be observed during all phases of operation, service, and repair of this instrument. Before applying power, follow the installation instructions and become familiar with the operating instructions for this instrument. GROUND THE INSTRUMENT To minimize shock hazard, the instrument chassis and cabinet must be connected to an electrical ground.
WARNINGS AND CAUTIONS WARNING and CAUTION statements, such as the following examples, denote a hazard and appear throughout this manual. Follow all instructions contained in these statements. A WARNING statement calls attention to an operating procedure, practice, or condition, which, if not followed correctly, could result in injury or death to personnel.
Compliance Statements Disposal of Old Electrical & Electronic Equipment (Applicable in the European Union and other European countries with separate collection systems) This product is subject to Directive 2002/96/EC of the European Parliament and the Council of the European Union on waste electrical and electronic equipment (WEEE), and in jurisdictions adopting that Directive, is marked as being put on the market after August 13, 2005, and should not be disposed of as unsorted municipal waste.
Contents 1 Safety Summary .......................................................... 1 2 Introduction ................................................................ 5 3 Quick Reference .......................................................... 6 4 5 6 7 3.1 3.2 Front Panel ......................................................................................... 6 Rear Panel .......................................................................................... 7 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.
2 Introduction Description The B&K Precision model 1747 is a general purpose dual range DC power source. This power supply can output more voltage at a lower current or more current at a lower voltage. The 1747 provides 0-60 V DC output, adjustable with both coarse and fine voltage controls for precise setting. The current output for the 1747 is 0-10 A for the 0-35 V range, and 0-5 A for the 35-60 V range, adjustable with both coarse and fine current controls.
3 Quick Reference 3.1 Front Panel 9 10 3 4 5 8 1 2 6 11 12 13 7 Figure 1 - Front Panel INDICATORS Either the CC or CV LED indicators will be lit whenever the unit is operating. The unit automatically changes from CV to CC operation when the preset current limit is reached. 1) CV (Constant Voltage) Indicator. The green LED is lit in constant voltage mode. Unit regulates output voltage at the value set by voltage controls. 2) CC (Constant Current) Indicator.
CURRENT CONTROL 7) Current Coarse Control. Coarse adjustment of current limit. Read value on the red LED display. 8) Current Fine Control. Fine adjustment of current limit. Read value on the red LED display. POWER CONTROLS 9) Power ON-OFF Switch. 10) Output ON-OFF Switch. OUTPUT TERMINALS 11) “-” Terminal (Black). Negative polarity output terminal. 12) GND Terminal. Earth and chassis ground. 13) “+” Terminal (Red). Positive polarity output terminal. 3.
4 Operating Instructions Safety Precautions Use only a polarized 3-wire AC outlet. This assures that the power supply chassis, case, and ground terminal are connected to a good earth ground and reduces danger from electrical shock. There is little danger of electrical shock from the power supply output, which produces a maximum of 60 volts dc. However, there may be great danger of electrical shock if the power supply output is connected to an external high voltage.
4.1 Instrument Hook-Up 1. 2. 3. 4. Turn off the power supply and the equipment to be powered during hookup. Connect the positive polarity of the device being powered to the red (+) terminal of the power supply. Connect the negative polarity of the device being powered to the black (-) terminal of the power supply. Figure 3 illustrates the grounding possibilities. a.
Figure 3 (A and B) - Grounding Possibilities Figure 3 (C and D) - Grounding Possibilities 10
4.2 Typical Constant Voltage Operation 1. 2. 3. 4. 5. 6. 7. Before connecting the device to be powered to the power supply, determine the maximum safe load current for the device to be powered and set the current limit value (see Setting Current Limit procedure in this section). The output voltage can be set using the voltage coarse knob (with a 1 V resolution) and voltage fine knob (with a 10 mV resolution). After the last adjustment you must wait 3 seconds until the state is saved.
4.3 Setting Current Limit 1. 2. 3. Determine the maximum safe current for the device to be powered. Adjust the coarse and fine current control for the desired current limit. Read the current value on the current LED display. Wait 3 seconds. The current limit (overload protection) has now been preset. Do not change the current controls settings after this step. Figure 5 - Setting Current Limit 4.4 Typical Constant Current Operation 1. 2. 3. 4. 5.
6. 7. Increase the coarse and fine current control setting until the desired constant current value is read on the display, or set the current limit in advance (before connecting the load) as described earlier in the Setting Current Limit procedure. If the load current drops below the constant current value, the CC indicator will go off and the CV indicator will light.
constant as the load current increases, up until the point where the preset current limit is reached. At that point, the output current becomes constant and the output voltage drops in proportion to further increases in load current. The crossover point is indicated by the front panel LED indicators. The crossover point is reached when the CV indicator goes off and the CC indicator comes on.
4.7 Connecting Two Power Supplies in Series Two power supplies may be connected in series to provide a variable 0-120 V output. In this configuration, the two power supplies can supply up to 60 V-10 A or 120 V-5 A. See Figure 8 for the connection scheme. When connected in series, the voltage controls of each power supply exercise control over a 0-60 V range. Add the LED display readings together or connect an external voltmeter across the load to determine the total output voltage.
Current equalizing resistors must be used as shown in Figure 9. However, the protective current limiting feature will prevent damage if current is temporarily unbalanced during set-up. When connected in parallel and operating in the constant voltage mode, determine the total load current limit and preset the current limiting for each power supply to half the total load current value. Then when the load is connected, set the voltage controls on the two power supplies for equal voltage readings.
5 Remote Operation The power supply can be connected to the RS232 interface using the 9-pin (DB-9) serial connector on the rear panel. The 1747 uses a null modem RS232 cable. The cable pin diagram for the DB-9 connector is shown in the picture below: Instrument RX PC 2 3 RX TX 2 3 GND 5 5 GND DB-9 connector TX DB-9 connector Figure 10 - RS232 Cable Pin Diagram For all communications over the RS232 interface, the power supply uses Xon/Xoff protocol.
5.1 RS232 Configuration Overview Baud Rate 9600 bps Parity Bits none Data Bits 8 Start Bits 1 Stop Bits 1 Flow Control Xon / Xoff Termination Character \r Table 1 - RS232 Configuration 5.2 RS232 Commands NOTE: All commands are case sensitive and must be capitalized. 1.VOLT xx.xx This command sets the output voltage value. The output voltage takes the programmed value only if the power supply is in Constant Voltage mode. Example: The output voltage is set at 5 V. VOLT 05.00 2. CURR x.
Example: The output current is set at 300 mA. CURR 0.300 3. SAVE The programmed values of the output current and voltage are saved. If the power supply is restarted, the values of the output current and voltage will be those previously saved. If the Output On-Off button is pressed at power on, then the power supply will start with Output Off state regardless of the previously saved state.
6. STAT? The power supply responds to this command with one of the following messages: CV if the power supply is in Constant Voltage mode CC if the power supply is in Constant Current mode 7. OUT ON Turn on the output. 8. OUT OFF Turn off the output. 9. IDN? The power supply responds to this command with the following message: B+K PRECISION 1747 Revision x.x 5.
6 Maintenance WARNING The following instructions are for use by qualified personnel only. To avoid electrical shock, do not perform any servicing other than contained in the operating instructions unless you are qualified to do so. 6.1 Fuse Replacement If the fuse blows, the CV or CC indicators will not light and the power supply will not operate. The fuse should not normally open unless a problem has developed in the unit.
6.2 Adjustments This unit was accurately adjusted at the factory before shipment. Readjustment is recommended only if repairs have been made in a circuit affecting adjustment accuracy, or if you have a reason to believe the unit is out of adjustment. However, adjustments should be attempted only if a multimeter with an accuracy of ±0.02% DCV or better is available (B&K Precision Model 5491B or equivalent). 6.
c) The power supply will enter in calibration mode and will display: Voltage display: C A L Current display: U 0 You can browse the calibration menu by turning the current coarse knob. Using the voltage coarse knob you can select one of the following calibration procedures: U U I I 0 F 0 F Zero voltage calibration Full voltage calibration Low current calibration Full current calibration The voltage fine and current fine knobs are not used.
c) Use the current coarse and fine knobs to adjust the value displayed by the power supply until the voltmeter indicates the closest value to 0V. d) Press the Output On-Off button to finish the calibration. While performing the zero voltage calibration, the current display will show Adc. After the zero voltage calibration, the message Done is shown on the current display for 1 sec. Then the power supply returns to the Calibration menu. 3.
4. Low current calibration a) Select “I 0” for low current calibration and press the Output On-Off button. When you initiate the low current calibration, the CV LED lights up and the power supply will display: Voltage display: I 0 Current display: ConA b) Connect a digital ammeter (B&K Precision 5491B or similar instrument) to the output terminals of the power supply to initiate the low current calibration procedure.
5. Full current calibration To finish the current calibration procedure, you must select the full current calibration option after the low current calibration. a) Select “I F” for full current calibration and press the Output On-Off button.
6. Leaving the calibration menu a) Turn off the power supply. b) When turned on, the power supply will have the same parameters programmed and saved before the calibration procedure. 6.4 Instrument Repair Service Because of the specialized skills and test equipment required for instrument repair and calibration, many customers prefer to rely upon B&K Precision for this service. We maintain a network of B&K Precision authorized service agencies for this purpose.
Er 07: Er 08: Er 09: Er 10: Er 11: Er 12: ADC not ready No reference voltage ADC conversion error ADC AVdd< 3.0V ADC AVdd> 3.6V Calibration constants checksum failed 7.
Full current calibration errors: Er 50: CC not low Er 51: CV not high Er 52: DAC out of range Er 53: ADC out of range Er 54: ADC system calibration failed Er 55: DAC full current constant checksum failed Er 56: ADC full current constant checksum failed 7.
8 Specifications 1747 Output Ratings ( 0 °C~40 °C) 0-60 V 0-10 A (0-35 V), 0-5 A (35-60 V) Voltage Current Load Regulation ±(% of output+offset) Voltage Current Line Regulation ±(% of output+offset) 0.01% + 5 mV 0.2% + 3 mA Voltage Current Ripple & Noise (20 Hz ~ 20 MHz) 0.01% + 3 mV 0.2% + 3 mA 1 mVrms ≤ 3 mArms ≤ 100 μs Voltage Current Recovery Time Meter Resolution 10 mV 1 mA (0-5 A) 10 mA (5-10 A) Voltage Current Meter Accuracy 0.5% + 5 digits 0.
Storage Temperature Storage Humidity Mechanical Specifications 5 °F to 158 °F (-15° to +70° C) 85% R.H. 30.2 lbs (13.7 kg) 10.75” x 6” x 14” (273 x 153 x 356 mm) Power cord, instruction manual, RS-232 cable, shorting bar Weight Dimensions (WxHxD) Supplied Accessories NOTE: All specifications apply to the unit after a temperature stabilization time of 30 minutes. Specifications and information are subject to change without notice.
9 Service Information Warranty Service: Please go to the support and service section on our website at www.bkprecision.com to obtain an RMA #. Return the product in the original packaging with proof of purchase to the address below. Clearly state on the RMA the performance problem and return any leads, probes, connectors, and accessories that you are using with the device. Non-Warranty Service: Please go to the support and service section on our website at www.bkprecision.com to obtain an RMA #.
10 Limited Two-Year Warranty B&K Precision Corp. warrants to the original purchaser that its products and the component parts thereof will be free from defects in workmanship and materials, for a period of two years from date of purchase. B&K Precision Corp. will, without charge, repair or replace, at its option, defective product or component parts. Returned product must be accompanied by proof of the purchase date in the form of a sales receipt. To obtain warranty coverage in the U.S.A.
(Page intentionally left blank) 34
22820 Savi Ranch Parkway Yorba Linda, CA 92887 www.bkprecision.com © 2011 B&K Precision Corp.
