I put in some test leads to cope with devices that won’t fit the sockets. For sockets, you can use cut off IC sockets or improvise from other connectors. SetupĪs the circuitry is so simple, point-to-point wiring can be used, using the terminals of the switches and sockets for mounting. Again, they will stay on until the supply is interrupted.ĭiodes can be connected to the A and K terminals and will conduct - lighting L1 - for only one position of S2. TRIACs are like SCRs, but test them in both polarity positions of S2. Thus it is not suited for testing power devices at high voltages and currents. It is limited as to test voltage (around 13V) and test current (around 15mA). It is compatible with most two and three terminal solid state devices. Only when you switch off the supply with S1 or S2 will it go off. Then, pressing the scroll button reveals the collector test current, VBE, IB, and the collector leakage. When S3 is ON, the SCR should trigger on and light L1, and will remain on even if S3 is put to OFF or GND. How do the atlas ones compare to others on the. To test an SCR, put S2 in the N position. Hello, Im looking to purchase a transistor tester for matching, identifying pins, weeding out bad ones, etc. Incidentally, Darlington BJTs may also light slightly with the upper touchpads, especially if you wet your fingers! Touch the two lower touchpads, and it should switch off. This is due to the gate capacitance of the MOSFET and indicates that the gate insulation is good.
L1 will stay lit if you remove your finger. When you touch the two upper touchpads, it should switch on and light L1. The Peak Atlas DCA55 is an intelligent semiconductor analyser that offers great features together with refreshing simplicity. To test a MOSFET, again select the polarity with S2, and put S3 in the center OFF position. L1 should illuminate for the ON position of S3, and it should be off if S3 is in the OFF or GND positions. To test a BJT, select the polarity with S2 and connect the device. When the device switches on, this is shown by a small lamp L1 which limits the current to around 300 mA - enough to show the device is working properly.
For testing MOSFETs with their high impedance gates, touchpads are also provided, so you can use your finger resistance (usually around 1 MΩ) instead. S3 - also a center-off type - applies a voltage and current to the base/gate of the device under test via a 680-Ω resistor. S1 may be omitted if S2 also has a center-off position. Figure 1: The only fancy part used in the Power Semiconductor Tester is S3 that has a center-off position.
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