Answer / ripul ghosh

nowadays 24V DC relays are used compared to 230V what was used before..relays are mainly there to isolate the controller from high power lines,
The signal from the controller will come to the relay and it will get energised to drive the output load.

Answer / nirmalya basu

to energise a output by plc and for its protection purpose
also.

Answer / ganesh

the relay works with AC and DC.
it provide the isolation between controller and devices works on ac and dc.
it is extremely useful when you need to control a large amount of current or voltage with small electrical signal.

Answer / suresh agravat

Example pressure transmitter input showing fiied full with liquid than send singnal through output to relay. When relay deenergised motor contactor not get supply and it will be motor or pump stop. Relay is basically on/off switch

Is there devices to convert mechanical energy/rotational energy into electrical energy.......? PLease suggest me....

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tion 0,50,100% equql to voltage formula?

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GWR radar transmitter working principle?

2 Answers   Tata Steel Limited,

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What is the full form of PMMC ?

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I have a orifice installed in plant which is design for 0~100 inH2O for 0~80MMSCFD, now due to process change the maximum flow is change to 120 MMSCFD so for this new process value what will be the DP across orifice.

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temptrure me ketne frequiency hote hai

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what is isolation Transformer???...

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Im working in a shopping center, it is also hotel and office building, two towers exactly and someone is proposing a PLC control for the HVAC system, but Im thinking of a DDC control system. in this case what is the difference between PLC and DDC control?

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What is the principle of a Pressure gauge?

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In a ball valve which require 24v dc supply to operate, whose solenoid valve doesn't have any + or - indication, how can we make wiring connectionto solenoid valve?

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Pls.could any one Clarify the following with an example. 1.At What condition Close on Rise and Close on Fall Pressure Switch contacts are used. 2.If Pressure is abnormal as per set pressure,if connecting Terminal of pressure switch breaks,how the voltage extends to Relay base. 3.Are these contacts come under fail safe philasaphy.

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Explain , how timer based pneumatic control valve will work ?

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