Fido's out of the doghouse now, thanks to Larry's automatic mail delivery notification system. When the postman opens the lid of Larry's mailbox, a photodetector mounted inside the mailbox activates a light-emitting diode inside the house, notifying him that mail has arrived. A special latch circuit ensures that the LED stays lit after the lid shuts, and a pushbutton allows Larry to reset the circuit after retrieving his mail.
Are you a Gadget Freak? Allied Electronics would like to send you on a shopping spree of up to $500 on its website at www.alliedelec.com/gf.asp. Email Design News your proposed project (must incorporate electronic components and involve sensing, motion, timing, and/or networking elements) to email@example.com, along with a description of how it works, and a parts list. If your project is selected, you'll receive the shopping trip of up to $500 and be featured in an upcoming edition of Design News.
|Mail's Here! Parts List|
|Amt||Part Description||Allied Part #|
|1||Ceramic Capacitor, 1.0 muF||881-5236|
|1||Ceramic Capacitor, 0.1 muF||881-3486|
|2||Carbon Resistor, 22 k||296-6330|
|1||Carbon Resistor, 1 k||296-6314|
|1||Carbon Resistor, 10 k||296-6326|
|1||Carbon Resistor, 1 meg||296-6348|
|1||Normally Open Pushbutton||757-2305|
|1||CD4011 Quad NAND||735-1323|