presentation on over-/under-voltage protection of electrical appliance
TRANSCRIPT
Presentation onOver-/under-voltage
protection of electrical appliance
Submitted by:rakesh roshan(0701209329)
nishant kumar(0701209350)abhishek pattnaik(0701209404)
narayan singh(0701209288) ashish kumar nayak(0701209345)
Under guidance of Er. Alice Pradhan
Introduction: Sudden fluctuation in supply is a very big problem in
industries and domestic applications. It causes a
major loss for industries, offices and homes.
This project gives a low cost and powerful solution for
this problem. This Circuit protects refrigerators ,ACs,
Microwave ovens as well as other appliances from
over and under voltage fluctuations.
Block diagram:
Circuit diagram
Simulated circuit diagram
Components:
TRANSFORMER
IC 7812
LM 324 (OPERATIONAL AMPLIFIER)
RELAY
ZENER DIODE
npn TRANSISTOR
RESISTORS ,CAPACITORS AND DIODES
TRANSFORMER
Step down transformer 230V/12V
Operating frequency is 50HZ.
Voltage is converted from 230v to 12v.
Current rating is 1A.
IC LM7812 (VOLTAGE REGULATOR)
Output current in excess of 1A.
Output Voltages of 12V.
current Internal thermal overload protection.
No external components required.
Output transistor safe area protection.
Internal short circuit limit.
IC LM324(OPERATIONAL AMPLIFIER)
Features :
Large DC voltage gain:100 dB
Wide power supply range:
Single supply:3VDC to 32 VDC
Dual supplies:±1.5VDC to ±16VDC
Differential input voltage range equal to the power supply voltage
Power drain suitable for battery operation
Large output voltage swing:0VDC to VCC-1.5VDC
PIN CONFIGURATION (LM 324)
Its rating is 12v, 200 ohm ,1 c/o relay.
Relay
•SPDT – Single Pole Double Throw.
A common terminal connects to either of two others.
Including two for the coil, such a relay has five terminals in
total.
A relay is an electrically operated switch.
A Zener diode is a type of diode that permits current not only
in the forward direction like a normal diode, but also in the
reverse direction if the voltage is larger than the breakdown
voltage known as "Zener knee voltage" or "Zener voltage“.
Zener diode of rating 6.0 v and 6.8 v are used in the circuit.
ZENER DIODE
BC 547 transistor is used in the circuit.
Transistor is used to energise the relay
when op-amp goes high.
npn TRANSISTOR
Diodes
Resistor
capacitor
RESISTORS ,CAPACITORS AND DIODES
APPLICATIONS: Industrial machinery
House hold items like TV, refrigerator, AC
Agriculture Motors
Water pumps
ADVANTAGES: Highly sensitive
Fit and Forget system
Low cost and reliable circuit
Complete elimination of manpower
Can handle heavy loads up to 7A
Auto switch OFF in abnormal conditions
Auto switch ON in safe conditions
CONCLUSION:It is helpful in protecting electrical appliances in very
effective way.
REFERENCE:
1) www.wikipedia.org
2) www.efy.com
3) www.google.com
THANKs..