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Difference between AC Voltage Stabilizer & AC Voltage Regulator ?

chuckey · 01-10-12, 17:56

I don't believe there is a specified difference. Where I used to work, stabilizers were based on saturated inductors, power up to 1kW . Voltage regulators (AVRs - Automatic Voltage Regulators) were based on motor driven rotary transformers, power up to 250 kW.
Frank

danishdeshmuk · 01-10-12, 18:44

the stabilizers that i have got have a transformer , 4 to 5 electro mechanical relays , pots are there with each of the relays to adjust the gain ...... and some little circuitry having zener diodes and resistors, capacitors and few transistors (normal NPN type) .....

zorro · 01-10-12, 19:15

If i'm not wrong, the distinction is:

Stabilizer: output voltage does not change (ideally) if input votage varies. But output can change if load current changes. Works in open loop (voltage output is not sensed).
Regulator: output voltage is mantained constant if input voltage OR load current change. Works in closed loop (voltage output is sensed).

Regards

Z

dineshdeshmuk · 01-10-12, 20:07

chuckey is right or zorro is right ?

aashitech · 01-10-12, 21:15

Dear Dinesh,
talking in Indian market context..here both of these terms refers to a device which controls the ac voltage fluctuation up to some defined limits and outputs a stable ac voltages within a specified output voltage window ( this window depends on the design itself).. these both terms are sometimes used interchangeably for same stuff..but YES there exists two different type of technologies for AC VOLTAGE STABILIZER or AC VOLTAGE REGULATOR... both of these technologies has there pros and cons in terms of cost and performance ...
There are two types of them one with a auto transformer with several winding taps connected to relays..these types are switches relays in certain combination so that out put remains at some defined window/limit.. here the output is specified to go +- few percentage of rated out put voltages..for example a unit with rated output voltages of 220 VAC will vary by a percentage value as specified by the manufacturer..generally this variation is +-9% ( note that this ouput variation will be over full input VAC range...range may be 140-285 VAC or 110-285 VAC )..
The other type is a design with a auto-transformer wound in VARIC shape..and a central shaft which moves a ARM ( having a conductor at outer edge) over the edges of this VARIAC.. this shaft is connected to a Motor ..and this motor is again governed by a circuitry which commands it to move clock/anticlockwise directions to compensate/buck/boost the output of auto transformer... these types of designs usually have tighter output voltage regulation.. even 1 % is possible..These types are generally called as SERVO VOLTAGE STABILIZERS.

Hope the above explanations will clear your doubts.. ... i kept the explanation simpler as much as i can..

kyrietec · 01-10-12, 21:56

They are the same .They made up of auto-transformer of different voltage output ,switching device,The control cct is made of voltage comperators.They are also input voltage range which on the transformer design.

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They are the same .They made up of auto-transformer ,switching device,The control cct is made of voltage comperators.They are also have input voltage range which depend on the transformer design.

danishdeshmuk · 02-10-12, 16:59

can we use servo voltage stabilizers on any device ? on computers and also with other loads whether refrigerators , tVs , deep freezers , split A.Cs etc .....

aashitech · 02-10-12, 17:47

Originally Posted by danishdeshmuk

can we use servo voltage stabilizers on any device ? on computers and also with other loads whether refrigerators , tVs , deep freezers , split A.Cs etc .....

YES you can..in fact relay type voltage stabilizers are only common for power ratings up to few KW of power..generally maximum upto 10 Kw...but servos stabilizers are comes in power rating up to many hundreds of Kw...

jeffrey samuel · 03-10-12, 17:58

Stabiliser does this it either gives a stable output or breaks the circuit if the voltage drop is too high or low

The regulator is bit different in its response to that of the stabiliser

chuckey · 03-10-12, 18:12

Originally Posted by jeffrey samuel

Stabiliser does this it either gives a stable output or breaks the circuit if the voltage drop is too high or low

The regulator is bit different in its response to that of the stabiliser

No the AC output just carries on with its voltage at the point when the stabilizer gave up. i.e. if the incoming mains should be 230V (100%), the stabilizer should hold it correct for a 90% value (207 in, 230 out), if the input falls to 190 V, the output would be 211V.
Our motor driven variacs would hold .25% for a +- 10% input, though they took a second to get there. There are also moving coil regulators we had one rated at 500kW, this was motor driven as well.
Frank

dineshdeshmuk · 04-10-12, 17:18

but here in india , they say that you can use servo stabilizers only for computers not for other inductive loads ..... like refrigerators, freezers , A.Cs , split A.Cs , TV etc

chuckey · 04-10-12, 18:04

You can say what you like in India. its a democracy, does not mean its correct though.

Frank

jeffrey samuel · 04-10-12, 18:10

Hello Frank

this is a forum

Anyways if it is a Stabiliser it can be used for any equipment

I seriously doubt it to be so

Dear Danish

Can you post some model specifications of what ever you have in your concern

aashitech · 04-10-12, 18:19

Originally Posted by dineshdeshmuk

but here in india , they say that you can use servo stabilizers only for computers not for other inductive loads ..... like refrigerators, freezers , A.Cs , split A.Cs , TV etc

No..that was true few years back when a device popularly known as "CVT"( Constant Voltage Transformer) was used as a pre-mains regulator to provide clean and regulated output to PCs... those were very accurate with only a fraction of a percent output variation over full rated operating mains input range..but at the same time they were very bulky and there input mains operating range was also very narrow just from 145-160 VAC ~ 285 VAC ac mains input...there output voltage regulation was based on principle of "Magnetic Resonance"..a transformer/capacitor pair was used..and this employed priciple itself was responsible for there not working well on Inductive load...later on these CVTs were replaced by relay based so called AVRs(Automatic Voltage Regulator)..these AVRs are now a standard feature of small UPS systems meant for powering home- SOHO segment PCs...
Infact they were so bulkier in size that today you can compare a present day 5KVA stabilizer transformer with just a 500 VA transformer of a CVT...

danishdeshmuk · 04-10-12, 20:32

but aashitech , i am talking about the servo stabilizers ..... the term CVT was for servo stabilizers ?

How to figure out that the servo stabilizer that i have got is not a CVT based OR its an AVR based , how to find that out ?

dineshdeshmuk · 04-10-12, 20:37

Originally Posted by chuckey

You can say what you like in India. its a democracy, does not mean its correct though.

Frank

just tell me whether its right or wrong : can use servo stabilizers only for computers not for other inductive loads ..... like refrigerators, freezers , A.Cs , split A.Cs , TV etc ??

aashitech · 04-10-12, 20:42

Dear,
The unit with relays connected to many taps of auto transformer is generally what we call as "Stabilizer"
..present days servos are made up of a variac(s) connected to a motor through a shaft..this motor is under control of a control circuitry ( usually SCRs are used as switches to energize motor..and control circuitry itself may be designed around simple comparators or an MCU).
To identify a CVT ..open it and look for one transformer with split windings on split bobbin..and in some manner a big capacitor or two are connected to this transformer...chances of any relays ( for any additional auxiliary feature) are rare...

dineshdeshmuk · 04-10-12, 20:52

ok if there are couple of big capacitors with a big transformer means its a servo stabilizer having CVT design and if there are relays , SCRs etc with a transformer then it means its a servo stabilizer having AVR stup which is the modern technique of controlling the voltage automatically for any kind and for any type of load , Right ???

aashitech · 04-10-12, 21:03

Originally Posted by dineshdeshmuk

ok if there are couple of big capacitors with a big transformer means its a servo stabilizer having CVT design and if there are relays , SCRs etc with a transformer then it means its a servo stabilizer having AVR stup which is the modern technique of controlling the voltage automatically for any kind and for any type of load , Right ???

NO NO..I think you are not reading my posts with great attention....
(1) Transformer + Relays = Voltage Stabilizer.
(2) Variac + motor + circuitry = Servo Stabilizer.
(3) Transformer with Split Winding on split Bobbin + big capacitors = CVT.

Yes for household application Voltage Stabilizer ( remember that relay one) is ok... and for all purpose including house hold Servos are good.