1. PHASE SEQUENCE CHECKER
FOR THREE PHASE SUPPLY
SUBMITTED BY

2. ABSTRACT
A 3-ph supply of 440V AC 50Hz is fed to a logic circuit comprising of NAND gates and OR gates to detect the sequence of R, Y, B by triggering a monostable timer 555.
While the sequence is not there the triggering to the timer is missed which is indicated by an LED driven from the output of the 555 timer.

3. BLOCK DIAGRAM

4. HARDWARE COMPONENTS:
TRANSFORMER (230 – 12 V AC)
VOLTAGE REGULATOR (LM 7812)
RECTIFIER
FILTER
555 TIMER
NAND GATE (4011)
IN4007
LED
RESISTORS
CAPACITORS

5. POWER SUPPLY Bridge rectifier 5v Regulator 230 V AC 50 Hz 5V DC
Filter(470µf)
12V step down
transformer

6. CD4011-NAND GATE Functional Diagram of CD4011 NAND gate truth table
input B
input A
output 1
Functional Diagram of CD4011

7. Features
Four Independent 2-input NAND Gates
Standard Pin Configuration
Wide Operating Voltage Range
Operating Temperature to 85oC
Low Power TTL
Fan out of 2 driving 74L Compatibility or 1 driving 74LS
5V±10V±15V parametric ratings
Symmetrical output characteristics
Maximum input leakage 1 mA at 15V over full
temperature range

8. 555 TIMER
The 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications.
The original name was the SE555 (metal can)/NE555 (plastic DIP) and the part was described as "The IC Time Machine".
Depending on the manufacturer, the standard 555 package includes over 20 transistors, 2 diodes and 15 resistorson a silicon chip installed in an 8-pin mini dual-in-line package (DIP-8)

9. PIN DIAGRAM OF 555 The 555 timer IC is a simple 8 pin DIL package IC.
It can:
be used as a monostable
be used as an astable
source or sink 100mA
use supply voltages of 5v to 15v
disrupt the power supply - use a decoupling
capacitor!

10. THANK ‘Q’