The document discusses an automatic phase selector (DPS) device that can automatically switch the power supply to loads from available phases. It senses which phase has power and switches the relay contacts to provide power from that phase to prevent interruptions. It is useful in developing countries with unstable power and prevents damage or losses from manual switching. The DPS has a phase sensing block, control logic block to decide phase priority, and relay driver block to control the relay. It can switch single phase loads and is compact, economical, and avoids mechanical contacts. It has applications in apartments, emergencies, industries, offices, malls, and engineering colleges.

1. Automatic phase assortment

2. Introduction
Digital phase selector which can also be known
as Automatic phase selector as the name
indicates automatic selection of phases when
there is absent or discontinued due to fault or
some other reasons of available phase.
This devices is used were there is availability of
3-ph i.e., (415v), 3-ph & 4-wire line. And you can
also add many number of phases as you like.

3. Hi I am DPS

4. Need of this device
Power instability in developing countries
creates the need for automation sources of
power to back-up the utility supply.
Most Industrial and commercial application are
dependent on power supply and if the process
of change over is manual, not only considerable
time is wasted but also the device or machine
may get damaged from human error during the
change over connections, incurring massive
losses.

5. Working Principle

7. Phase sensing & switching block :
 The phase from which the power has to be
taken is sensed and corresponding switching
operation is performed.
Control logic block :
 The control logic circuitry decides the phase
priority for one out of Three lines.

8. Relay driver block :
 The relay driver gets signal from the control
logic circuit .
 The relay driver section gives electrical signal
to the strip of the relay and relay
contacts closes thus the power
flows to load.

9. CIRCUIT DIAGRAM

10. Ratings of components
 Transformer ratings : 230/12 v.
Current : 5A
 Relay ratings : Type: SMCU
Contact: 1.5A/230v
Coil : 12v, DC/300 ohms.
 Preset resistor 5k.
 Transistor : BC 548.

11.  Zener diode.
 Capacitors : 25v, 100 micro F & 25v, 220 micro F.
 Resistors : 10k ohm.
 LED’s
 Diode IN4007.

12. Advantages of DPS :
 Power Interruption during running of
load can be eliminated.
 Compact in size.
 Economical.
 No Mechanical contacts.
 Can be used for all single phase loads .

13. Applications
 Can be used in Apartments.
 Used in EMERGENCIES i.e., in ICU ‘s, Operation Theatre’s.
 Used in industries & offices.
 In Shopping malls.
 Can also be used engineering colleges.