http://www.engineeringslash.com/digital-ic/door-knob-alarm.html Engineering blog- electronic circuits , electronic projects,electronic schematic,electronic design,simple circuit and hobby circuits Tue, 08 Nov 2011 18:23:08 +0000 hourly 1 http://wordpress.org/?v=3.3.1 http://www.engineeringslash.com/digital-ic/door-knob-alarm.html#comment-6 Colin Mitchell Fri, 22 Jan 2010 08:03:41 +0000 http://www.engineeringslash.com/?p=107#comment-6 BEL187 transistor has not been produced for 20 years. A good substitute is BD139 or any transistor with a current cabability of 1 amp or more. BEL187 transistor has not been produced for 20 years. A good substitute is BD139 or any transistor with a current cabability of 1 amp or more.

]]> http://www.engineeringslash.com/digital-ic/door-knob-alarm.html#comment-5 Colin Mitchell Fri, 22 Jan 2010 07:56:05 +0000 http://www.engineeringslash.com/?p=107#comment-5 The positive of the electrolytic should be connected to pin 3 as this pin will have positive potential on it to charge the electro. The positive of the electrolytic should be connected to pin 3 as this pin will have positive potential on it to charge the electro.

]]> http://www.engineeringslash.com/digital-ic/door-knob-alarm.html#comment-4 admin Fri, 22 Jan 2010 06:24:13 +0000 http://www.engineeringslash.com/?p=107#comment-4 Please be more descriptive . Please be more descriptive .

]]> http://www.engineeringslash.com/digital-ic/door-knob-alarm.html#comment-3 Colin Mitchell Thu, 21 Jan 2010 23:14:19 +0000 http://www.engineeringslash.com/?p=107#comment-3 The 10u is around the wrong way on the Door Knob Alarm The 10u is around the wrong way on the Door Knob Alarm

]]>