Over Voltage and Under Voltage Protection System using Trip Switch

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Introduction

• Over Voltage Under Voltage Trip Switch to protect
  the load from damage. The fluctuation in AC mains
  supply is frequent in homes and industries. The
  sensitive electronic devices in these conditions
  can get easily damaged. It is preferable to have
  a tripping mechanism to protect the load.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Block Diagram
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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Hardware Components

• LM 339 quad comparator
• LED
• Voltage Regulator
• Resistors
• Potentiometer
• Capacitors
• Diodes
• Relay
• Lamp
• Transformer

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Transformer

• Transformer is an electrical device.
• It transfers electrical energy between two or
  more circuits through electromagnetic induction.
•  A varying current in one coil of the transformer
  produces a varying magnetic field, which in turn
  induces a voltage in a second coil.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Capacitor

• Capacitors store and release electrical charge.
• They are used for filtering power supply lines,
  tuning resonant circuits.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Over Voltage

• When the voltage in a circuit or part of it is
  raised above its upper design limit, this is
  known as overvoltage.
• The conditions may be hazardous.
• Depending on its duration, the overvoltage event
  can be transient - a voltage spike - or
  permanent, leading to a power surge.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Low Voltage

• Under Voltage condition occurs when a load is
  suddenly connected to a power supply.
• The load will start to draw current, this causes
  the voltage to temporarily drop.
• Multimeter is set to measure voltage Instruments
  for measuring voltages including the voltmeter,
  the potentiometer, and the oscilloscope.
• The voltmeter works by measuring the current
  through a fixed resistor, which, according to
  Ohm's Law, is proportional to the voltage across
  the resistor.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Description

• The tripping mechanism is to protect the load
  from damage.
•  The fluctuation in AC mains supply is frequent
  in homes and industries.
• The sensitive electronic devices in these
  conditions can get easily damaged. 
• The proposed system will trip the load in the
  event of the input voltage falling below/above a
  set value.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Description

• Two 555 timers are used as window comparator.
• This delivers an error output if the input
  voltage to them crosses the range beyond the
  voltage window.
• A relay is then operated to cut-off the load for
  safety reasons. A lamp is used as load in this
  project.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Working Principle

• A 220 volts ac is given as a input to the
  transformer.
• A step down transformer is used, as it serves to
  reduce the pressure remaining 12 volts, through a
  D1-D4 connected to Direct rectifier bridge
  circuit.
• This rectifier converts ac to dc but the obtained
  dc is not pure dc it is a pulsating dc, to obtain
  pure dc we are using regulator so that we can
  obtain pure dc.
• And the capacitors are used for filtering.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Working Principle

• In the regulator the voltage across the pins 1
  and 2 will be the input and output will be from
  the pins 2and 3.
• Here we are using another IC which as 14 pins.
• The 4th pin in this IC act as V cc and the 11th
  pin will be grounded.
• Here we are using two zener diodes of 6.8v and
  6v.
• The 6.8 volts zener diode is connected to the 2nd
  pin of IC2/1 and 6 volts zener diode is connected
  to the 5th pin of IC2/2.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Working Principle

• The voltage coming from the diodes D2 and D4 goes
  to 3rd pin of IC2/1 and 6th pin of IC2/2.
• Here IC2/1 act as high voltage detector and
  IC2/2 act as low voltage detector.
• When the voltage obtained across the 3rd pin is
  greater than the voltage at the 3rd pin then
  IC2/1(high voltage detector) will function and
  the switch will be closed and load will be and
  LED glows.
• This is the indication of high voltage.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Advantages

• High reliability
• High performance

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Disadvantages

• In this project, relay is used as it is making of
  sound. So some noise pollution occurs.
• It is specified of minimum range of the higher
  voltage and lower voltage.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Future Scope

• This system can also be enhanced in future by
  interfacing it with a GSM modem to convey alert
  message to the user via SMS to take appropriate
  action.

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Mains Supply Sensed Over Voltage Under Voltage
Trip Switch
Conclusion

• Mains supply sensed over voltage under voltage
  trip switch will indicate the high voltage and
  low voltage. Due to this we can safe guard our
  home appliances without damaging the equipments.

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