Commonly used detection methods for machine tool electrical faults include voltage method, resistance method, short-circuit method, open-circuit method, and current method.
(1) Voltage Method: This method uses instruments to measure the voltage value at a point on a circuit to determine the range of electrical faults or component faults in machine tools.
(2) Resistance Method: This method uses instruments to measure the continuity of a circuit or component to determine the fault location.
(3) Short-Circuit Method: This method involves temporarily short-circuiting a suspected faulty circuit or component and observing any changes in the fault state to determine the location of the fault. When using the short-circuit method to check multi-stage circuits, if short-circuiting a component causes the fault to disappear or significantly decrease, the fault is before the short-circuit point; if the fault remains unchanged, it is after the short-circuit point. For example, if the output potential of a stage is abnormal, short-circuiting the input of that stage will restore the output potential to normal, indicating that the stage is normal. The short-circuit method is also commonly used to check whether components are functioning properly. For example, short-circuiting the base and emitter of a transistor with tweezers and observing the change in collector voltage can help determine if the transistor has an amplification effect. In TTL digital integrated circuits, the short-circuit method is used to determine whether gate circuits and flip-flops are functioning properly. Short-circuiting the control electrode and cathode of a thyristor can help determine if the thyristor is malfunctioning. Additionally, the input terminals of certain instruments (such as electronic potentiometers) can be short-circuited to observe changes in the instrument readings and determine if the instrument is being interfered with.
(4) Open-circuit method: In repairing machine tool circuits, sometimes it is necessary to disconnect the circuit for inspection to meet specific needs. This method is called the open-circuit method.
(5) Current method: The method of determining the fault point by measuring whether the current flowing through a certain line is normal is called the current method.