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Return to BlogUninterruptible Power Supply (UPS): Basic Circuit Diagram
The circuit drawn pertains to a regular industrial UPS (Uninterruptible Power Supply), which shows how the batteries take control during an outage in electrical supply or variation beyond the normal limits of the voltage line, without disruption on the operation providing a steady regulated output (5 Volts by LM7805) and an unregulated supply (12 Volts).
The input to the primary winding of the transformer (TR1) is 240V. The secondary winding can be raised up to 15 Volts if the value is at least 12 Volts running 2 amp. The fuse (FS1) acts as a mini circuit breaker for protection against short circuits, or a defective battery cell in fact. The presence of electricity will cause the LED 1 to light. The light of LED will set off upon power outage and the UPS battery will take over
The circuit was designed to offer more flexible pattern wherein it can be customized by using different regulators and batteries to produce regulated and unregulated voltages. Utilizing two 12 Volt batteries in series and a positive input 7815 regulator, can control a 15V supply.
Industrial UPS are generally categorized as:
Standby – battery backup and surge protection
Line Interactive – variable-voltage transformer and regulates the input AC voltage
Online – supplies all or at least a part of the output power
Source:www.zen22142.zen.co.uk/Circuits/Power/ups.htm

4 years ago: I like using this especially during crucial times when I have to finish my reports then suddenly there will be blackouts!!! damn electric company!!!
3 years ago: what is the main diffreance between in the circuit diagram in the offline ups & the online ups.
3 years ago: how long will this UPS last and what is the full load that it can handle?
3 years ago: hai, gud day. im doing my project about UPS which can supply two units of computer and have at least a run time of 2 hours long. pls do help me, i badly needed ol ur helps.. Tnx a lot in advance.
3 years ago: is it true that it will run for 2 hours?
3 years ago: Hi good day im doing my project about ups i want use 11 point realy
did this possible pls help ,me thnx
3 years ago: WHAT IS THE U.P.S SEFTY INSIDE
3 years ago: is it possible to get a simple ups rating 3 watt , 3 volt .
3 years ago: i need a circuit diagram of ups. i m a technician of electronics .i make a a ups so u help me some schematic circuit diagram provide me .
2 years ago: what is diff.between online and offline ups.
2 years ago: R this the only components the circuit utilizes? Pliz rply.
2 years ago: I'm doing a project right now about extending the battery lifespan of the UPS can anyone help me please... Is it OK to use a Thermoelectric Generator (TEG) that will be tapped into the heat sink?? TEG is a thermo-transducer, will it be enough to generate voltage that will be connected directly to the battery?? i wish someone could help me..
2 years ago: Hai gud evening i got a inverter tripping problem last night when EB power failure,we have a 3phase 250kva UPS 3nos parllel connection(each ups have 2 seperate battery banks(1bank 32nos )in series connection),all ups invertors are getting tripped at time no one can gave the battery back up(single minit also)when EB power failure, what is the actul problem ? could u plz help me to give a incident report.
2 years ago: i want to design an offline ups. Can someone send me all d circuit diagrams as i've not found any ckt worthy for my project....
2 years ago: Mr Louie,
In TEG we use thermocouples for generating small amount of voltage,so be remember that.
1 year ago: i want to produce the small hydro-power station.
1 year ago: the oscillation of this circuit those not last long. why
1 year ago: why we use transformer in ups