It's annoying to have your telephone call interrupted by someone picking up an extension phone and it can be embarrassing to accidentally pick up a line that is engaged. The low cost easy-to-build FK306 circuit has a bright LED that shows clearly when a line is picked up.

Technical Specification

• Power Supply : 3VDC @ 10mA.
• PCB Dimensions : 1.51" x 0.91" x 0.6" (38.35mm x 23.11mm x 15mm)

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