The Larkin Power Components, Inc. M5500 is a portable power semiconductor tester designed for evaluating various power semiconductors, including SCRs/Thyristors, Diodes, IGBTs, Transistors, and most MOS FETs. The device is housed in a rugged yellow case, making it suitable for field use. It operates at voltages as high as 6400V, emphasizing the need for strict adherence to safety precautions and operating instructions.
Function Description:
The M5500 performs three primary tests:
- PFV (Peak Forward Voltage) Test: Measures the peak forward voltage and resulting peak leakage current when a half-wave 50-60 Hz forward voltage is applied to the device.
- PRV (Peak Reverse Voltage) Test: Measures the peak reverse voltage and resulting peak leakage current when a half-wave 50-60 Hz reverse voltage is applied to the device.
- Gate Voltage and Current Test: Measures the DC gate voltage and current required to trigger the device into its On-state. For transistors, this measures the Base Current. The Anode (Collector) supply uses a half-wave 50/60 Hz waveform.
The tester's circuits conform to JEDEC test standards RS397 for SCRs and Diodes, which is crucial for accurate and reliable semiconductor evaluation. It provides a Gate Voltage high enough to test for turn-on of IGBTs and MOS FETs, and can test both NPN and PNP bipolar transistors. The E/I (Voltage/Current) curve of the device can be displayed on an external X-Y oscilloscope, offering a visual representation of the device's characteristics.
Important Technical Specifications:
- Input Voltage:
- M3K-120V Test Set: 100-125V, 50-60Hz, 2A
- M3K-240V Test Set: 220-245V, 50-60Hz, 2A
- High Voltage Mode (PRV/PFV):
- Peak Reverse and Forward Voltage: 0 - 5800 VPK
- Peak Leakage Current @ 3 Mohm: 1.83 mA
- Short Circuit Current: 10 mA
- Test Duration: max. 15 seconds
- Gate Mode:
- Gate Voltage: 0 - 20 VDC, 10 ohm source impedance
- Anode Voltage: 14 - 18 V, 10 ohm, 1/2 sine wave
- Panel Meters (PRV/PFV Mode):
- Peak Anode Voltage: 6400 VPK
- Peak Leakage Current: 19.99 mA
- Panel Meters (Gate Mode):
- Gate Voltage: 19.99VDC
- Gate Current: 1999 mA
- Oscilloscope Input (PRV/PFV Mode):
- X-axis (voltage) sensitivity: 1.0 V/div=1000 V/div
- Y-axis (current) sensitivity: 1.0 V/div=10 mA/div
- Oscilloscope Input (Gate Mode - Anode Voltage/Current Curve):
- X-axis (voltage) sensitivity: 2.0 V/div=10 V/div (Anode Voltage)
- Y-axis (current) sensitivity: 2.0 V/div=1 A/div (Anode Current)
- Case Dimensions (L x W x D): 19" x 14" x 7" / 49cm x 36cm x 18cm
- Weight: 20 Lbs. / 9.072 kg
- Operating Temperature Range: 15°F to 120°F (-10°C to 50°C)
- Relative Humidity: up to 80%
- Test Standard: JEDEC JC22, RS397
Usage Features:
The M5500 is designed for ease of use while prioritizing safety.
- Voltage Control: A "Voltage Control" knob allows the operator to slowly increase the test voltage. It must always be at the zero position (fully counter-clockwise) before turning the unit on or connecting/disconnecting a device under test.
- Function Switch: A "Function Switch" allows selection between PRV, PFV, and GATE test modes.
- TEST Button: A "TEST" button initiates the test. It should never be pressed for more than 15 seconds.
- Panel Meters: Digital meters display Peak Voltage (V) and Peak Leakage Current (mA) in PRV/PFV modes, and Gate Voltage (V) and Gate Current (mA) in Gate mode.
- TRIGGER INDICATION Light: This light illuminates during the Gate test to indicate when the device triggers.
- Oscilloscope Option: The device includes connectors for an external X-Y oscilloscope, enabling visual analysis of E/I curves. This is particularly useful for observing "break-over points" and understanding device characteristics.
- Clamping Device: A simple clamping device is recommended for testing pressure pack (hockey puck) devices, requiring approximately 200-300 lbs of compression.
- Lead Connections: Specific instructions are provided for connecting Anode, Gate, and Cathode leads for various device types (SCRs, Diodes, GTOs, Power Modules, Transistor Modules). Crucially, the Anode and Cathode leads must not be mixed up to prevent high voltage application to the gate, which could damage the tester.
- Grounding: The tester must be plugged into a properly grounded three-wire receptacle. It is also recommended to connect the instrument to ground via the "GROUND" terminal on the front panel. For IGBTs or Darlington Transistor modules, the base plate of the module under test MUST be connected to the "GROUND" terminal.
- Testing Procedures: Detailed step-by-step procedures are provided for testing different types of power semiconductors, including:
- Pressure Pack SCRs (Thyristors)
- Pressure Pack Diodes
- Stud-mounted diodes
- GTOs (Gate Turn-off Thyristor)
- Power Modules (e.g., Dual Thyristor Bridge, Thyristor/Diode, Diode/Diode, single Diode or Thyristor Modules)
- Transistor Modules (IGBTs and DARLINGTONs)
- Diode Modules for Rotating Rectifiers
- Transistor Testing: For transistor modules, a 100k ohm, 1/4 watt or larger resistor should be connected between the BASE and EMITTER terminals. The connection order for leads is critical: Ground, Emitter, Base, Collector, and disconnection in reverse order to prevent shorting. Typical turn-on voltage for transistors is 5-6V.
Maintenance Features:
The manual emphasizes proper handling and safety to ensure the longevity and safe operation of the M5500.
- Safety First: The most critical aspect of maintenance is adhering to safety guidelines. The device operates at high voltages, and misuse can be extremely dangerous. Only authorized and trained personnel should operate the equipment.
- Grounding: Always ensure the tester is properly grounded using the 3-wire line cord and, if applicable, the front panel GROUND terminal.
- Device Isolation: The part to be tested MUST be isolated and de-energized before connecting to the tester. Connecting to live equipment will damage the tester.
- Voltage Control: Always return the Voltage Control to zero before connecting or disconnecting devices.
- Test Duration: Do not keep the TEST button pressed for more than 15 seconds.
- Physical Contact: Never touch the test leads or the device under test while the TEST button is depressed.
- Rated Voltage/Current: NEVER exceed the manufacturer's blocking voltage or leakage current ratings. If the maximum leakage current is reached before the rated blocking voltage, or vice versa, STOP the test. Exceeding these ratings can lead to instant failure or degradation of the device.
- Troubleshooting: If the "TRIGGER INDICATION" light does not turn on during a Gate test, or if the oscilloscope graph does not transition as expected, it indicates a faulty Gate (or Base for transistors), and the device should be replaced.
- Environmental Conditions: The device is designed for specific operating temperature and humidity ranges, which should be respected to ensure optimal performance and prevent damage.
The M5500 is a specialized tool for professionals involved in the testing and maintenance of power semiconductors, providing a robust and standardized approach to device evaluation.
Need help?
General
To Next Page