Editing Silicon controlled rectifier (section)

===Forward blocking mode===
In this mode of operation, the anode (+, p-doped side) is given a positive voltage while the cathode (&minus;, n-doped side) is given a negative voltage, keeping the gate at zero (0) potential i.e. disconnected. In this case junction '''J1''' and '''J3''' are [[P–n diode|forward-bias]]<nowiki/>ed, while '''J2''' is [[P–n junction|reverse-bias]]<nowiki/>ed, allowing only a small leakage current from the anode to the cathode. When the applied voltage reaches the breakover value for '''J2''', then '''J2''' undergoes avalanche breakdown. At this breakover voltage '''J2''' starts conducting, but below breakover voltage '''J2''' offers very high resistance to the current and the SCR is said to be in the off state.