Model 1739 DC Power Supply with 0.
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 ............................................................. 7 3.1 3.2 4 Operating Instructions .................................................. 9 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 5 RS232 Configuration Overview ...................................................... 19 RS232 Commands ............................
2 Introduction Description The B&K Precision model 1739 is a high quality, low current DC power source. This power supply provides 0-30 volts dc output, adjustable with both coarse and fine voltage controls for precise settability. The current output is 0-1 amps, adjustable with both coarse and fine current controls. Two large LED meters continuously monitor the output voltage and current. The VOLTAGE meter is green, while the CURRENT meter is red.
Reverse polarity protection prevents accidental damage to the power supply from improper connection to an external device, and current limiting protects the equipment being powered, as well as the power supply. The output is isolated from chassis and earth ground, which permits full flexibility of connections. When needed, the (+) or (-) polarity may be strapped to ground, or either polarity may be floated to an external voltage.
3 Quick Reference 13 3.1 Front Panel 5 3 1 6 7 4 8 2 9 10 11 12 Figure 1 - Front Panel INDICATORS Either the CV or CC 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. Adjusts current limit in constant voltage mode. Adjusts constant current value in constant current mode. Current can be read from the red LED display. 8) Current Fine Control. Adjusts current limit in constant voltage mode. Adjusts constant current value in constant current mode. Current can be read from the red LED display. POWER CONTROLS 9) Power ON-OFF Switch. OUTPUT TERMINALS & CONTROL 10) “-” Terminal (Black). Negative polarity output terminal.
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 30 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 11
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 1V 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. 4. 5. Determine the maximum safe current for the device to be powered. Temporarily short the (+) and (-) terminals of the power supply together with a test lead. Adjust the coarse and fine current control for the desired current limit. Read the current value on the current LED display. The current limit (overload protection) has now been preset. Do not change the current controls settings after this step.
4.4 Typical Constant Current Operation 1. 2. 3. 4. 5. 6. 7. Before connecting the device to be powered to the power supply, determine the maximum safe voltage to be applied, and set the voltage controls to obtain that voltage reading on the voltage LED display. Determine the desired constant current value. Set the coarse and fine current control to minimum (1mA). Wait 3 seconds. Turn off the power supplies output and connect it to the device to be powered. Turn on the power supplies output.
4.5 Constant Voltage/Constant Current Characteristic The working characteristic of this power supply is called a constant voltage/constant current automatic crossover type. This permits continuous transition from constant current to constant voltage modes in response to the load change. The intersection of constant voltage and constant current modes is called the crossover point. Figure 7 shows the relationship between this crossover point and the load.
4.6 Saving the Power Supply’s Current State The current state of the power supply is saved after 2 seconds from the last adjustment or after the “SAVE” command is received through the RS232 interface. 4.7 Connecting Two Power Supplies in Series Two power supplies may be connected in series to provide a variable 0-60 volt output. In this configuration, the two power supplies can supply up to 60V-1A. See Figure 8 for the connection scheme.
4.8 Connecting Two Power Supplies in Parallel Two power supplies may be connected in parallel to double the maximum load current. In this configuration, the two power supplies will provide 0-30 volt output at up to 2 amps. 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.
If the current equalizing resistors are not well matched, it is preferable that the voltages be slightly unbalanced to achieve current balance. Be sure that the supplies are adequately balanced so that both remain in the CV mode. When connected in parallel and operating in the constant current mode, the voltage controls of both supplies should be preset to the same value.
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 CR (0x13) Table 1 - RS232 Configuration 5.2 RS232 Commands Note : All commands are case sensitive, therefore be sure all letters are CAPITALIZED before sending it to the instrument. 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.
CURR 3000.0 3. VOLT? This command returns the voltage measured to the output terminals of the power supply: xx.xxV The voltage value returned is the same as the one displayed on the voltage display. 4. CURR? This command returns the current measured to the output terminals of the power supply: xxx.xmA The current value returned is the same as the one displayed on the current display. 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.
6.3 Calibration Calibration is a procedure that ensures that the power supply will work properly, with parameters specified within the Specifications section.
I I 0 Low current calibration F Full current calibration The voltage coarse and fine and current fine knobs are not used. Important note! In order to perform a correct calibration procedure, you must select the full voltage calibration option just after the zero voltage calibration option, and the full current calibration option just after the low current calibration option. 2.
3. Full voltage calibration To finish the voltage calibration procedure, the full voltage calibration must be done after the zero voltage calibration. a) Select “U F” for full voltage calibration and turn the voltage coarse knob. The power supply will display: Voltage display: U F Current display: hex number A hexadecimal number between 0 and FFFFh will be shown on the current display. During the zero voltage calibration, the CV LED is lit.
b) Connect a digital ammeter (B&K Precision 5491B or similar instrument) to the output terminals of the power supply to initiate the zero current calibration procedure. If a digital ammeter is not connected within 30 seconds, the power supply will abandon the current calibration procedure and return to the Calibration menu. The CV LED indicator will go off and the CC LED indicator will light on.
b) Connect a digital ammeter (BK Precision 5491B or similar instrument) to the output terminals of the power supply to initiate the full current calibration procedure. If a digital ammeter is not connected within 30 seconds, the power supply will abandon the current calibration procedure and will return to the Calibration menu. The CV LED indicator will turn off and the CC LED indicator will light on.
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. To use this service, even if the instrument is no longer under warranty, follow the instructions given in the Warranty Service Instructions section of this manual. There is a nominal charge for instruments out of warranty.
Er 20: CC not high Er 21: CV not low Er 22: DAC out of range Er 23: ADC out of range Er 24: ADC system calibration failed Er 25: DAC zero voltage constant checksum failed Er 26: ADC zero voltage constant checksum failed Full voltage calibration errors: Er 30: CC not high Er 31: CV not low Er 32: DAC out of range Er 33: ADC out of range Er 34: ADC system calibration failed Er 35: DAC full voltage constant checksum failed Er 36: ADC full voltage constant checksum failed Zero current calibration errors: Er 40:
7.3 Command Errors ”Communication Error” “Syntax Error” “Out of range” 8 : RS232 framing, parity, or overrun error : invalid syntax was found in the command string : a numeric parameter value is outside the valid range for the command Specifications 1739 Output Ratings ( 0 °C~40 °C) Voltage Current Load Regulation ±(% of output+offset) 0-30 V 0-999.9 mA Voltage Current Line Regulation ±(% of output+offset) 0.04% + 1 mV 0.4% + 0.1 mA Voltage Current Ripple & Noise (20 Hz ~ 20 MHz) 0.
Temperature Humidity Temperature coefficient (0 °C~35 °C) ±(％of output+offset) 32 °F to 104 °F (0 °C to 40 °C) 75% R.H. Storage Temperature Storage Humidity Mechanical Specifications 5 °F to 158 °F (-15° to +70° C) 85% R.H. 300 ppm/°C 9 lbs (4 kg) 5.5” x 6.2” x 12.5" (140 x 158 x 318 mm) Weight Dimensions (W x H x D) 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 Three-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 three 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.
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