Getting Started With Your PLS
Testers frequently get severely shaken during shipment. For this reason we urge you to examine your tester closely for damage or for modules that have moved or become disconnected or similar effects of severe vibration.
Please examine the tester from the back first since you can examine much of the interior through the back door. This drawing shows the proper cable and power cord connections on the back of the tester.
Next remove the black screws holding the three front panels. The top two chassis are on slides and can be pulled out for examination. The bottom panel gives you access to the front side of the raw bias and 2KV supply section.
The middle front panel is hinged and secured by two thumbscrews on the panel. It is probably not necessary to lower the panel unless you can see something in the lower part that needs to be checked. If you do need to lower the panel, you will have to disconnect four large wires terminated in lugs. These wires are short and would prevent the panel from swinging down.
Please be sure that everything is secure before plugging in the tester.
SAFETY
There are dangerous voltages and current sources, present inside the cabinet, and servicing should be done only by trained technicians using suitable precautions to avoid contact with these sources.
In addition to the AC line power, there are both high voltage and high current test power sources. The high voltage supply is normally off when not testing but if out of control by the microcontroller it could produce as much as 2500V. There are limiting resistors between this supply and the front panel terminals that limit the short circuit current to about 10mA.
The low voltage "Forward Current" supplies have a maximum voltage of about 28V but the maximum current is VERY high. The energy available is sufficient to melt or weld such metallic objects as rings, watch bands, bracelets, etc.
THIS HIGH CURRENT COULD BE AVAILABLE ON THE FRONT PANEL TERMINALS.The red "STOP" button unlatches the relays energizing the test power supplies and discharges the storage capacitors within a few seconds. You should check this button on a regular basis to be sure that it works.
AC LINE POWER
The PLS1000CM tester uses about 5A of line current from a nominal 120VAC power line at 50-60 Hertz. This 5A is the typical line current when running tests such as 4066 or TR at maximum rated power. There is a much larger surge of current for a few cycles when the "ON" button is first pressed. For this reason it is wise to use a power line that is otherwise lightly loaded.
STARTUP
Turn on the small power toggle switch on the lower right of the top chassis, but do NOT press the "ON" button yet. Press the release button on the fold down control panel and view the LCD display. You should see a message with the model, release date, and instructions to "Press any key". If you do not see this message, there is something wrong and you must NOT press the "ON" button.
If you see the above message, it is ok to press "ON". When you do this, you should hear the fans begin to operate and a red LED indicator on the middle panel will indicate that test power is on.
CAUTION
The PLS1000CM can produce a large amount of power on the diode terminals. There could be high "Reverse" voltage there. Although the reverse current is limited to about 10mA, this could give you a very unpleasant shock. The "Forward" voltage is fairly low (about 28VDC maximum). But the peak current can be VERY HIGH. It is best to check a new tester first with a wirewound power resistor and a relatively low current in order to be sure that the control circuits are working. Before doing any actual diode tests, please carefully connect (with the test power "OFF") a 100 Ohm 10 W resistor from the Anode force post to the Cathode "TF" post. The TF post bypasses the internal SCR, so any power supply output would be on this post. With the test power "ON", there should be only a few mV at most across this resistor or from any terminal to the chassis.
We suggest that your first real test should be something similar to a VF test at 10A, 1mS width, with a 0.1 Ohm resistor. Please read the programming sections of this manual first for instructions. Please see the drawing that shows the proper hookup of the test socket. This hookup is different for Thermal tests and all other types of tests.
If this VF test produces the expected 1V reading, it is reasonable to assume (tentatively) that the controls and power supplies are in working order.
Please read the information in the manual carefully before testing any valuable diodes, since this tester can produce enough power to destroy even fairly large diodes. If you have questions please feel free to call us for assistance.
Suggestions
The software program, VFS2, that is included with the tester makes programming and diagnostic testing very easy. If you can attach a PC running this software (using the serial port and the cable supplied) we think you will find this a very valuable addition.
For example: The VF vs IF function can plot voltage vs current for a diode or a test resistor over a fairly wide range of currents. This allows a quick check of current programming and voltage readout capabilities.
There are many other logging and plotting functions available also.
Programming of the tester is easier with the software, although you can do it with the control panel also.
If you program the tester with the front panel control, this setup will be saved in a nonvolatile memory. If you turn the tester off and later on, the setup last used will be still present. Programming the tester with the remote computer does NOT overwrite the program stored in the tester's long term memory.
Various test setups can be saved in files using the <F2> key (save) and then recalled using <F8> (load). This allows frequently used setups to be easily restored without manual re-entry.