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gw_instek_gpc-3030dq_power_supply

Instek GPC-3030DQ Power Supply

The GPC-3030DQ is a triple output 195W linear DC power supply. Channel 1 and 2 are fully adjustable and Channel 3 is fixed at 5V/3A with ripple and noise at less than 2mVrms. Overload and reverse polarity protection keep the unit and its loads safe from unexpected conditions.The GPC-3030DQ contains a temperature controlled cooling fan for thermal protection.The GPC features continuous or dynamic internal load selection and serial or parallel tracking for application flexibility.


The instrument consist of two identical, independently adjustable DC power supplies. A front panel switch selects one of three modes of operation: independent, series and parallel. In the independent mode, the output voltage and current of each supply are controlled separately, and each supply is isolated up to 300V from output to chassis or output to output. In the tracking mode, both outputs are automatically connected in series or parallel, and the controls of the left supply adjust the magnitudes of both the positive and negative output voltages. Because the outputs are connected in a tracking configuration, any internal disturbance in the master supply (such as drift or ripple) will cause an equal percentage change in the outputs of both the supplies.

Each power supply (except fixed 5V) is a completely transistorized, well-regulated, constant voltage/constant current supply that will furnish full rated output voltage at the maximum output current or can be continuously adjusted throughout the output range. The front panel current controls can be to establish the output current limit (overload or short circuit) when the supply is used as a constant voltage source (independent or tracking modes) and the voltage controls can be used to establish the voltage limit (ceiling) when the supply is used as a constant current source (independent mode only). The supply will automatically cross over from constant voltage to constant current operation (current limited operation in the tracking mode) and vice versa if the output current or voltage exceeds these preset limits. Each supply had its own front panel meter that can measure output voltage or current. When operated with the front panel mode switch in the tracking position, the instrument is automatically internally connected in autotracking configuration.

General Info

Usage

1. Setting Current Limit


(1) Determine the maximum safe current for the device to be powered.
(2) Temporarily short the(+) and(-) terminals of the power supply together with a test lead.
(3) Rotate the VOLTAGE control away from zero sufficiently for the CC indicator to light.
(4) Set the meter selection switch to the A position to select the current metering mode.
( 5) Adjust the CURRENT control for the desired current limit. Read the current value on the Ammeter.
(6) The current limit (overload protection) has now been preset. Do not change the CURRENT control setting after this step.
(7) Remove the short between the(+) and(-) terminals and hook up for constant voltage operation.

2. Constant Voltage/Constant Current Characteristics


The working characteristic of these Power Supplies is called a constant voltage/constant current automatic cross­ over 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. Fig. xx shows the relationship between this crossover point and the load.
For example, if the load is such that the power supply is operating in the constant voltage mode, a regulated output voltage is provided. The output voltage remains constant as the load increases, up until the point where the present current limit is reached. At that point, the output current becomes constant and the output voltage drops in proportion to further increases in load. The 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.

Similarly, crossover from the constant current to the constant voltage mode automatically occurs from a decrease in load. A good example of this would be seen when charging a 12-volt battery. lnitially, the open circuit voltage of the power supply may be preset tor 13.8 volts. A low battery will place a heavy load on the supply and it will operate in the constant current mode, which may be adjusted for a 1 amp charging rate. As the battery becomes charged, and its voltage approaches 13.8 volts, its load decreases to the point where it no longer·demands the full 1 amp charging rate. This is the crossover point where the power supply goes into the constant voltage mode.

3. Operation Mode

(1) Independent Operation

The “MASTER” and “SLAVE” supplies each provide a Oto rating volts output at up to rating amps. This procedure covers the use of the MASTER and SLAVE supplies only when they are used independently from one another. When used in the INDEPendent operating mode·, the operating controls of the two power supplies are completely indepen­dent and either supply can be used individually or both can be used simultaneously.
A. Disengage both TRACKING mode switches (both switches out) so that the power supply is in the INDEPendent operating mode.
B. Adjust “Voltage” control and “Current” control to the desired output voltage and current.
C. Turn off the power supply and the equipment to be powered during hook-up.
D. Connect the positive polarity of the device being powered to the red(+) terminal of the power supply.
E. Connect the negative polarity of the device being powered to the black (-) terminal of the power supply.
F. Fig. yyy illustrates the connection procedure.

(2) Series Tracking Operation

When the series tracking mode of operation is selected, the position (red) terminal of the SLAVE supply output is
internally connected to the negative (black) terminal of the MASTER supply.
In the series tracking mode, the maximum output voltage of both the MASTER and SLAVE supplies can be simultaneously varied with one control. The maximun SLAVE supply voltage is automatically set to the same as the
MASTER supply by using the MASTER VOLTAGE controls.

A. Set the power supply to the TRACKING SERIES mode by engaging the left TRACKING switch and release the right TRACKING switch.
B. Set the MASTER A/V switch to the V (voltage metering) position, and the SLAVE A/V switch to the A (current metering) position.

NOTE:
Simultaneous metering of both current and voltage i::an be Obtained in this mode of operation by setting one of the displays for current metering and one for voltage metering. In this case, the output voltage {across the two supplies ) is actura!ly
double the displayed value. For example. if the MASTER display is set for voltage metering and the SLAVE display for
current metering, the output voltage across the MASTER positive (red) terminal and the SLAVE negative (black) terminal would be double the reading on the MASTER LED Display (since both supplies are putting out the same voltage). The
actual output current would be the value read from the SLAVE LEO Display (since the two supplies are wired in in series,
current flowing through.each supply must be equal).

C. Set the SLAVE CURRENT control to the fully clockwise position. The maximum current is set using the MASTER CURRENT control. Follow the instructions for “Setting Current Limit” (INDEPENDENT USE OF “MASTER” OR “SLAVE” SUPPLY section, using the MASTER CURRENT control.


NOTE:
Because the supplies are being used in series, either CURRENT control can be used to set maximum current. If desired, the MASTER CURRENT control can be rotated fully clockwise and the SLAVE CURRENT control can be used to adjust the maximum current value. Because current through the two supplies must be equal when they are being used in series, the lowest CURRENT control setting will set the maximum output current.

D. Adjust the output voltage to the desired level using the MASTER VOLTAGE controls.
E. Turn off the power supply and the equipment to be powered during hook-up.
F. If “single supply” operation is desired, this allows the power supply to be used as twice the voltage and rating current simply by using the negative (black) terminal of the SLAVE supply and the positive (red) terminal of the MASTER supply, the configuration as shown in Fig. zzzz.
G. If the chassis or common of the equipment being powered is separate from both the positive and negative polarity power inputs. The output of the SLAVE (negative) supply tracking the output of the MASTER (positive) supply, the configuration as shown in Fig. aaaa.


(3) Parallel Tracking Operation


In the parallel tracking mode of operation, both supplies are strapped together (in parallel). This allows for a rating voltage supply with a double rating current capability. Only the MASTER output terminals are used for parallel track· ing operation. In the parallel tracking mode, the SLAVE supply output voltage and current track the MASTER supply output voltage and current.

A. Set the power supplies to the TRACKING PARALLEL mode by engaging both TRACKING switches.
B. Set the MASTER A/V switch to the V (voltage metering) position, and the SLAVE A/V SWitch to the A (current metering) position. Output voltage will now be read from the MASTER LED Display. Output current is exactly double the value read from the SLAVE LED Display (because each supply is providing the same amount of current).
C. Because both voltage and current of the SLAVE supply track the MASTER supply, the maximum current and voltage are set using the MASTER controls. Using the MASTER supply output jacks, follow the instructions for “Setting Current Limit''. Remember that the actual current output at the MASTER supply output jacks is double the reading on the SLAVE indicator meter.
D. Adjust the output voltage to the desired level using the MASTER VOLTAGE controls.
E. Turn off the power supply and the equipment to be powered during hook-up.
F. Connect the positive polarity of the device being powered to the red (+) terminal of the MASTER power supply.
G. Connect the negative polarity of the device being powered to the black(–) terminal of the MASTER power supply. The configuration as shown in Fig. bb.

(4) 5V Fixed Power Supply Operation


The fixed 5V supply provices a 5V DC output with a 3 amp current capacity. The supply is ideal for use with TTL circuits.

A. Turn off the power supply and the equipment to be powered during hook-up.
B. Connect the positive polarity of the device being powered to the red{+) terminal of the 5V supply.
C. Connect the negative polarity of the device being powered to the black(􀂗) terminal of the 5V supply.
D. If the red OVERLOAD indicator lights, too much load has been placed on the supply. This will cause voltage and current' to drop and prevent proper operation of the 5V supply. To correct this situation, the load on the supply must be decreased so that no more than 3 amps of current are required.

(5) Dynamic Load Operation & Application

A. When select to dynamic load position, the max peak current is 1.7 times rating current. The features are only applied for audio circuit of amplifier and audio production lines. Change jump wire (DL1 master, DL2 slave) to J109 master, J309 slave at “ON” position.
Ref. to Fig. ccc. Adjustment Location.
B. For other application and testing (Safety or CE .. etc.), must set the jump wire at “OFF” position.

Maintenance

Cleaning
To clean the power supply, use a soft cloth dampened in a solution of mild detergent and water. Do not spray cleaner directly onto the instrument, since it may leak into the cabinet and cause damage. Do not use chemicals containing benzine, benzene, toluene, xylene, acetone, or similar solvents. Do not use abrasive cleaners on any portion of the instrument.

Fuse
If the fuse blows, the CV or CC indicators will not light and the power supply will the not operate. The fuse should not normally open unless a problem has developed in the unit. Try to determine and correct the cause of the blown fuse. The fuse is located on the rear panel. Disconnect power cord before replacing fuse. For continued fire protection, only replace with T6.3A 250V fuse.

Calibration
See manual for Independent Adjustment.

More Learning

Supporting Equipment

Tool Type Make / Model / Link
Test Leads GW Instek GTL-104A Test Lead, U-type to Alligator Test Lead, Max. Current 10A, 1000mm
GW Instek GTL-105A Test Lead, Alligator to Banana Test Lead, Max. Current 3A


Equipment Status

For availability and current status of this equipment, please see Tools Inventory, or the parent area under which this tool is maintained.

Primary Consumables

Consumable Part NumberProduct Link
ConsumableN/AN/A


gw_instek_gpc-3030dq_power_supply.txt · Last modified: 2018/02/18 13:01 by leisa_fearing