21-07-2012, 04:43 PM
POWER LIMITER
POWER_LIMITER.docx (Size: 209.86 KB / Downloads: 64)
INTRODUCTION
Electricity is one of the major sources of power in this world, but along with its utilization, a major portion of it is wastage and stealing. Electricity board is facing a lot of problem in conservation of electric power. We realized the problem and work over it. From this we got the inspiration to design a POWER LIMITER.
Earlier we were using fuse for protection from over- load, fuse is a device, which operates on overload (current). If the excessive current flows through the circuit then the fuse wire melts and it is to be replaced after every operation rating of fuse wire used.
To overcome the drawback of fuse, Circuit Breakers are used to break the circuit. . These are used in power grids substations and now a days miniature circuit breakers are used for domestic purpose. During overload it breaks the circuit by separating the moving contact. This moving contact is to be settled manually.
Circuit breakers are very common device being used by electrical persons for switching ON/OFF the electrical loads. But the load switching is required automatically day or night, switching is required with respect to time period, switching is required with respect to applied load and all this continuously and automatically. An attempt is made to design such system, which would do above switching automatically. Such system would eliminate fuse links operators job to switch the load to ON/OFF at different time intervals etc. hence we are designing a system which can perform all above mentioned jobs automatically and called as POWER LIMITER.
FEATURES OF POWER LIMITER:
Output power is limited to set watt.
Any attempt to draw more power results in flickering of lights.
Can be mounted anywhere on the electric line or on the electric post.
Helps in average billing.
Reduces manpower.
Eliminates doubts of wrong billing.
This is feasible through power limiter of 200w/300w/400w etc. up to 2000w and rating can be increased according to the requirement of consumer.
Can be made cheaper than ENERGY METER in large-scale production.
Avoids power thefts.
Provides SURGE PROTECTION to the load, which is not possible through energy meter.
Helps to limit farmers to draw power up to 5 to 10 BHP as per the permission granted.
DESCRIPTION
Mechanical energy meters are not suitable for low power load as don’t work at such a low load. The sand particles get deposited on the spindle, which restricts the free motion of the wheel in mechanical energy meters.
Mechanical energy meters are viable for tampering and meter reading can be manipulated. Mechanical energy meters are costly and due to improper maintenances they get damaged.
We can also attach a LIGHT DETECTOR to POWER LIMITER to provide the supply only at night. Because there are lots of free consumers (i.e. single battery connection consumer). Which would give more finance to an electricity board?
Light is sensed by light detector and based on the presence/absence of light, the power is switched to load detector through the control block.
The load detector block compares the applied load with the set load and switches the load to OFF if the applied load is more than the set load and vice-versa. Power supply delivers the power to different blocks at different voltages.
Before the era of microprocessors, circuits were constructed using discreet logic like various gates, counters, flip-flop, decoders, mono stable and registers. Circuit diagram was designed as per the requirement. Prototype PCB is made interconnecting the logic component as per the design.