Inverter.........!

[koolguy]

I don't know how to find whether it is giving sq. or sin wave.

 

[audioguru]

The schematic either shows an extremely simple square-wave circuit or a very complicated high frequency PWM pure sine-wave circuit.
Please attach the schematic.

 

[koolguy]

It is using 4 n-channel mosfet, few transistor, op-amp, etc.

 

[audioguru]

Why don't you post your schematic? Then we can see if it is very simple with a square-wave output without voltage regulation.

 

[koolguy]

sorry i can't post the schematic for this i don't want to open my UPS as it is in warranty..!


ok, i have 6,600microfarad capacitor i have seen that if i short it, multimeter shows 0v and slowly-2 it reading increases to 1 volt max. pls tell why this happen in capacitor charge by surrounding.

 

[chemelec]

ok, i have 6,600microfarad capacitor i have seen that if i short it, multimeter shows 0v and slowly-2 it reading increases to 1 volt max. pls tell why this happen in capacitor charge by surrounding.

That is Normal With Most Electroltic Capacitors.
Probably because of "Dielectric Absorbtion" Properties of Capacitors.

 

[blueroomelectronics]

Post your schematic.

 

[koolguy]

I have Digital multimeter which can't measure ac current, as i was making rectifier from 18-19V transformer, soldering Diode and capacitor it gives 25-26V this dc current i can measure with D.multimeter it show's near by 7amp.

pls tell how to find ac current given by transformer.

 

[audioguru]

You must never connect a current meter directly to the output of a power supply because a current meter is nearly a dead short.
A current meter is supposed to be connected in series with a load.

 

[koolguy]

ok, tell how to find Transformer ac current output with this multimeter..?

 

[chemelec]

Its Time you go to a School and Study some "BASIC Electronics".

It seems no matter what we tell you, You Don't Listen!

 

[audioguru]

ok, tell how to find Transformer ac current output with this multimeter..?

If your meter does not read AC current then buy a meter that reads AC current.

But if you do not know what is the max allowed AC current from a transformer then look at its spec's on its datasheet, or throw it away and buy a transformer that has a datasheet.

 

[chemelec]

Besides, You Really Can't really Measure the Actual Output Current of the Transformer.

Since your Amp-Meter MUST Connect in Series with a Suitable Load, You can Only measure the Current going to that Load.

And If you Know the Wattage of your Load and If you Measure the Actual Voltage with the Load Connected, than you can Calculate the Current. Basically the Watts / Volt = Amps

 

[koolguy]

I can also find current with rating, but i was asking without rating how to calculate it, as there is a relation of RMS = Vmax./1.41 for the voltage , when i connect rectifier on it's terminal the output current is 7amp. is there any relation to find it's RMS current.

 

[audioguru]

If you connect a DC current meter to the output of the rectifier then you are simply shorting the output with your meter. The circuit is not rated and is not designed to drive a short. The transformer and/or rectifier will burn out.
A current meter is supposed to be connected in series with the load to show the current in the load.

If you don't know the max current rating of your transformer then throw it away and buy a transformer that comes with a datasheet!

 

[chemelec]

I can also find current with rating, but i was asking without rating how to calculate it, as there is a relation of RMS = Vmax./1.41 for the voltage , when i connect rectifier on it's terminal the output current is 7amp. is there any relation to find it's RMS current.

That 1.414 Figure is ONLY For TRUE SINE WAVE.
Your Inverter is NOT True Sine Wave, It is Most Likely SQUARE WAVE.

You Could take the Transformer Apart and See What Size of wires are on the Primary and Secondary.
Than Based on a Reasonable Value of about 700 Circular Mils per Inch, You could Calculate a Typical Current rating.
(A Circular Mil is 1/1000 of an inch.)

And are you ONLY interested in the Transformer Spec's?
Or the Actual Output of the Inverter?

If for the Inverter, There are other things to Consider:
Is this transformer Wound Correctly for an Inverter Circuit?
EXAMPLE: The Primary Winding NEED to be Bifilar Wound, For Maximum Efficiency.

 

[koolguy]

That 1.414 Figure is ONLY For TRUE SINE WAVE.
Your Inverter is NOT True Sine Wave, It is Most Likely SQUARE WAVE.

You Could take the Transformer Apart and See What Size of wires are on the Primary and Secondary.
Than Based on a Reasonable Value of about 700 Circular Mils per Inch, You could Calculate a Typical Current rating.
(A Circular Mil is 1/1000 of an inch.)

And are you ONLY interested in the Transformer Spec's?
Or the Actual Output of the Inverter?

If for the Inverter, There are other things to Consider:
Is this transformer Wound Correctly for an Inverter Circuit?
EXAMPLE: The Primary Winding NEED to be Bifilar Wound, For Maximum Efficiency.

sir,I am not talking about inverter simple ac to dc rectifier..!

 

[chemelec]

An AC to DC Rectifier Won't Help you to Find the Output Current.

Yes the Output Voltage is 1.313 Times the RMS.
EDIT I MENT to say 1.414 Times the RMS.
And the Output Current is .707 of the Input Current.

But SOME of this OUTPUT Current gets WASTED in the FILTERING PROCESS!

AS I SAID PREVIOUSLY:
You Could take the Transformer Apart and See What Size of wires are on the Primary and Secondary.
Than Based on a Reasonable Value of about 700 Circular Mils per Inch, You could Calculate a Typical Current rating.
(A Circular Mil is 1/1000 of an inch.)

 

[koolguy]

sir, from where this 1.313 constant value you have taken from, and in ltspice software to make transformer circuit it ask how much impedance of sec. and primary coil , pls tell relation between no. of turn's and impedance.

 

[Transistorman]

sir, from where this 1.313 constant value you have taken from, and in ltspice software to make transformer circuit it ask how much impedance of sec. and primary coil , pls tell relation between no. of turn's and impedance.

its will be useless if you keep trying to learn the WHOLE from internet

better you find a teacher