T2 also remains off since its base is grounded. In this state, White LED remains off. When the light falling on the LDR decreases, it cease to conduct and T1 forward bias providing base current to T2.

Watt Stopper/Legrand has developed a new relay panel to provide fail-safe emergency lighting in a variety of commercial settings. The Emergency Relay Panel option is UL924 listed for use on emergency ...

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