Transcript Presentation

CK 1000 LIGHT ALARM
Project
IME-458 SPRING 2014
FINAL PROJECT
FABIANO REUTER
MECHANICAL ENGINEERING
Design
 The CK1000 Sounds an alarm when light is
detected using the following:
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HEF14011B IC , a 4 NAND Gate IC -handles logic
Photoconductive photocell a.k.a. Light dependent resistor
(LDR)- senses light
Trimpot potentiometer- adjusts resistance in “tank” circuit
Logic Circuit
•
The HEF14011B IC, also known as 14-pin dual inline package
(14-DIP), is a quad NAND gate interconnect (there are 4 of
them), 2 inputs, 2 outputs.
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It is wired up to oscillate when the input to it goes high, that is
the BC557 transistor (Q2) turns on after light is detected by the
LDR. The oscillating output from the HEF14011B IC turns the
BC547 transistor (Q1) on and off.
•
When Q1 is ON, the tank circuit (the choke and the piezo
buzzer), charges up. When the Q1 turns OFF the piezo (which
acts as a capacitor) discharges into the choke and makes a 'click'
as it does so.
Sensing Light
The PDV-P7002 are (CdS), photoconductive photocells designed
to sense light from 400 to 700 nm. These light dependent
resistors (LDR) are available in a wide range of resistance
values. They are packaged in a two leaded plastic-coated
ceramic header.
PCB Schematic
PCB Layout
Finished Product
Assembly
 All components are through-hole
 Soldered to board
 Components arranged with DIP Trace to minimize
board size.
 DIP-14 Mount allows for replacement of the IC
unit in case of damage.
Wooden Chest
Sound turns off in about 3-5 seconds after lid is shut.
Questions?