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Description

This is a modified version of the astable multivibrator. The circuit was recently created to evaluate N-channel MOSFETs (such as the IRF830). It’s important to note that this circuit isn’t intended to identify all defective MOSFETs or detect every possible fault condition within a MOSFET. A functioning MOSFET, when incorporated into the astable multivibrator, will result in the LED flashing. Conversely, a malfunctioning MOSFET will prevent the LED from illuminating.

MOSFETs

N-channel MOSFETs, like the IRF830, are semiconductor devices used to switch and amplify electronic signals. These devices control current flow when a voltage is applied to their gate terminal. They are frequently utilized in switching power supplies, motor control circuits, and various other applications where rapid switching is required. The IRF830 is a commonly used MOSFET known for its relatively high current handling capability and suitability for a wide range of power applications. Its characteristics make it a practical choice for this testing circuit.

Circuit diagram

Note: The diode is a light-emitting diode (LED).

The other half of the astable multivibrator employs an NPN transistor, contributing to the circuit’s affordability. Almost any NPN transistor can be used in this circuit. The NPN transistor positioned to the right functions as a common-emitter buffer, simultaneously driving the LED due to the pulses received from the MOSFET drain.