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FEC VF40CM Diode Tester - Page 2


A programmable constant current power supply/pulse generator provides the forcing current pulses for all of the tests including the IM current for the Thermal tests.

A 14-bit Analog-to-Digital converter with a dual scale differential input amplifier reads the VF of the device under test.

The tester is controlled by a micro-controller with our VF40CM firmware. It can remember your test setup if you wish in its non-volatile EEPROM. The VF40CM firmware is contained in a plug-in EPROM that can easily be changed if we add or change features in the future.

The VF40CM contains an interface that can communicate with diode handlers for production testing. In this case it is usually used with an optional external orienter to accommodate diodes presented with random orientation.



The forcing current scales are 0- 40.00mA, 400.0mA, 4.000A, and 40.00A.

The voltage readout scales are 0-1.6383V and 0-24.574V


The tester supplies 5A for any pulse width

At 8A the maximum TH is 50ms

At 20A the maximum TH is 25ms

At 40A the maximum TH is 10ms


The VFS2 and STATS software provided, for use with an optional user-supplied PC, are DOS programs. They can be used with DOS, FreeDOs or with WINDOWS any version up to WIN98. They are not recommended for WINDOWS XP, 2000 or VISTA.

FEC can supply a suitable PC at extra cost that runs a version of DOS called FreeDOS, which is distributed free under GPL licensing.


Frothingham Electronics Corporation
44 Crystal Lane
PO Box 629
Wakefield, NH 03872-0629
FAX: (603) 522-9710
Phone: (603) 522-6620

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