Telephone In-Use Indicator

See image above

Copyright 2006: Bill Bowden [url]http://ourworld.compuserve.com/homepages/Bill_Bowden/[/url]Parts:1x 3 volt battery
2x 3.3 MOhm resistors
1x 680 KOhm resistor
1x 100 Ohms resistor
1x 0.1 uF capacitor
1x 2N3904 NPN amplifier
1x 2N3906 PNP amplifier
1x LED

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