Automate Your R+D Testing With Free Software. Scale up your DC Current Capacity When You Need To
Each DC1000A can provide 0-25 Amps DC bias to check the saturation performance of the core material. This can be further extended by using multiple units in parallel with your unit under test.
This technique can be used manually or over RS232 commands. In both use-cases the operator (or software) controls the stacked units as if they were one unit.
This works if you are an AT customer and wish to control multiple units via the AT test program, or if you wish to use multiple DC1000A's with your own LCR meter manually or with the DC Sweep Software.
Stacking the units is simple – by connecting the comms on each unit, one becomes the master and controls the other slave units. Connecting 2 units together would give you the ability to generate 50 Amps, 3 units to give 75 amps and so on.
The DC1000A precision DC bias source features unique patented technology that permits its use with any LCR meter, decreases error currents by a factor of 10, and allows you to interconnect up to 20 units to achieve bias currents of up to 500A.
This guide explains how to set up your environment to use multiple DC1000s with an LCR meter.
As an example configuration, we will connect three DC1000As together to provide up to 75A, while measuring using an LCR meter.
1 CONNECT RS232 AND INTERLOCKS
Using the 77-046 straight through 9w-9w M-F leads provided with the unit:
1 Connect RS232 OUT from the first DC1000 to the RS232 IN on the second DC1000
2 Connect RS232 OUT from the second unit to the RS232 IN on the third DC1000. The first unit will automatically become the “MASTER” unit and will control the other units in the chain. This is needed even if you are still controlling the DC1000s manually
3 Insert your interlock system or interlock override plug into the Interlock IN on the first unit
4 Connect Interlock OUT on the first unit to Interlock IN on the second unit
5 Connect Interlock OUT on the second unit to Interlock IN on the third unit
2 OPEN CIRCUIT COMPENSATION
1 Remove any UUT (unit under test)
2 Connect the DC1000 outputs in parallel using the test leads provided. Ensure the leads common together at the point of contact with the UUT. Try to keep all test leads in the same position as when the UUT is present
3 Turn the DC1000s and LCR meter ON and allow to warm up for 30 minutes
4 Set bias current to 0.00A, using rotary knob on the MASTER DC1000, if needed
5 On the MASTER unit, set DC1000 output to ON by pressing “output” button. The green OUTPUT LEDs on all three units will light. The two slave units’ orange REMOTE LEDs will also light, showing that they are being controlled by the Master unit
6 Perform open circuit compensation on your LCR meter (sometimes called “Open Correction”)
7 Remember to compensate at all frequencies at which you want to measure
8 When complete, press the Master OUTPUT button to turn all the DC1000s OFF
3 SHORT CIRCUIT COMPENSATION
1 Fit a short between all leads. A bus bar or thick copper wire is ideal for this, as it will give good contact to all four clips. Try to keep all test leads in the same position as when the UUT is present
2 Set the DC1000A to 0.00A, using the rotary knob if needed
3 On the MASTER unit, set the DC1000 output to ON, by pressing the “output” button. All three green OUTPUT LEDs will light. The two slave units’ orange REMOTE LEDs will also light, showing they are being controlled by the Master unit
4 Perform short circuit compensation on your LCR meter (sometimes called “Short Correction”)
5 Remember to compensate at all frequencies at which you want to measure
6 When complete, press the Master OUTPUT button to turn all the DC1000s OFF
4 MAKING MEASUREMENTS
Once you have compensated the LCR for the leads and DC1000s you can make measurements under load.
1 Turn the DC1000 output OFF
2 Add your UUT back into the circuit, attempting to keep the test leads in the same position as when compensating
3 Select the DC bias current you require using the rotary knob on the MASTER unit
4 The Slave units will adjust automatically. In the example shown each unit is providing 15A to give a total DC bias current of MAKING MEASUREMENTS
5 Enable the DC bias current by pressing OUTPUT on the MASTER unit
6 Perform measurements using the LCR
7 Adjustments can be made to the DC bias level while the output is enabled (and the LCR is measuring) using the rotary knob on the master unit
5 BEST PRACTICE / WARNINGS
• DO NOT disconnect the UUT or LCR while the DC1000 is operating
• Always remove the DC bias current by disabling the OUTPUT button before disconnecting either the UUT or the LCR meter
• Always try to keep all leads in the same position to improve the accuracy of the compensation, and hence the accuracy of your measurements
• NEVER daisy-chain the leads from unit to unit. Each cable can carry only 25 AMPS. Hence the leads must be joined at the UUT using a bus-bar or similar that can carry the maximum current you wish to apply.
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