Van

Stand-by POWER loss preventer

GUIDED BY:- H.O.D.:- SUBMITTED BY:-

Er. Harpreet Kaur Er. Omesh Swarna soni , Hemant sharma

Hada Sohail Khan ,Naveen Parmar

Aashish Dangi

Branch:-Electronics& comm.

IV semester, II year

SHRI YOGINDRA SAGAR INSTITUTE OFTECHNOLOGY & SCIENCE, RATLAM

introduction

EQUIPMENT DISCRIPTION

Working

Advantages

Disadvantages

applications

Stand-by power loss preventer is a device which

prevents the power during when the system is on

stand-by mode. It is based on the principle of

electromagnetic induction (EMI is used to activate

and de-activate the circuit). It mainly works on

the CRT(cathode ray tube).

RELAY COILRL1: 6V

RL2 : 9V , IC/0

DIODED1: 1N4148

D2: 1N4007

D3: 1N4007

D4: 1N4007

CapacitorC1: 1000 uF, 25V

C2: 100uF, 25V

C3: 1000 uF, 25V

RESISTORSVR1: 10K ohm

VR2: 10K ohm PRESET

R1: 470 ohm

R2: 1K ohm

R3: 100K ohm

R4: 100 ohm

R5: 1000 ohm

LED

LED1

LED2

TRANSISTORT1: BC547

TRANSFORMERX1: (step down:-230V-24V) 12-0-12V, 500 Ma

INPUT SUPPLY230V AC supply

TV socket

.

The circuit senses high-energy electromagnetic radiation

from the CRT monitor when it is ‘on’. A relay coil (L1) connected

between inverting pin 2 and non-inverting pin 3 of IC CA3130 (IC1)

senses the electromagnetic radiation from the monitor to generate a

minute current. IC CA3130 is CMOS op-amp with gate-protected p-

channel MOSFET in the inputs. It has very low input impedance &

requires very low input current (typically, 5pA). The high input

impedance and low input current make IC1 suitable for this application.

The internal bias of IC1 at 5pA is sufficient is not required. Preset

VR1is used for offset null adjustment so that the output of IC1 is low

when the TV is in the standby mode .

CKT DIAGRAM OF SPLP

Initially, when the TV is ‘off’ output pin 6 of IC1 is low and LED1

doesn’t glow. To start the TV ,press switch S1 for a few second,

Capacitor C1 charges through resister R2 and transistor T1conducts to

energies relay RL1.The relay gives power to the TV through its normally

open (n/o)contacts. when the TV is switched on, the sense coil receives

the electromagnetic radiation ,the output of UC1goes high & LED1

glows .The high output from IC1 is fed to the non-inverting input of UC

TLO71(IC2) via diode D1 & the TV remains ‘on’ IC2 is a low–noise,

JFET input op-amp.

When you switches off the TV using the remote control, the

electromagnetic field around it disappears & the output of IC2 also goes

low. As a result , the output of IC1goes low& transistor T1 stops

conducting. The time taken by capacitor C1 to discharge through resister

R3 gives delay of a few second to de-energies the relay after which the

mains power to the TV is cut off. The TV can be switched on again only

by momentarily pressing switches S1.

Power supply for the circuit is derived from a 12v-0-12v

step-down transformer (x1).Diode D3 & D4 rectify the

secondary output of the transformer and capacitor C3 filters

the ripples.IC7809(IC3)provides regulated 9v to the circuit

for operation.

Assemble the circuit on a general purpose PCB and enclose

in a suitable cabinet with an AC socket for the TV. Place the

top Or sides and supply the power .Adjust VR1until LED1

goes off. At this time , the relay should remain de-energies

.Press switch S1 for a few second until the relay energies to

switch on the TV and S1 ,the TV will remain ‘on'. Use the

remote to switch it off in standby mode….

Eliminating "standby" electricity loss from homeappliances could save upto 25 percent on electrical bills,study shows.

It save 45% of the main power supply.

When the TV is on standby mode our system get automatically

switch ON & allow the required power to flow through the

electronic device.

Due to the use of IC, the circuit is minimized.

Durable & long life.

When the device is in stand-by mode, the efficiency ofthe relay decreases due to the fluctuation in the magneticfield generated by the relay.

It can be used only in CRT contained devices & not in LCD etc.

Its circuitry is complicated.

It is expensive.

Effected by weather condition.

Mainly used in CRT equipments,

which are mainly found in 90% of

houses.

On using more CRT components, it

can be used for the power saving of a

no. of electronic device.

THE

END