Inverter with one transformer for charging battery!

[abhay kulkarni]

I am working on a inverter having 12vdc input and 230vac output.
there is only one transformer used in it. I am not understanding how battery is charged through it when ac mains is present.
is it possible to use same transformer as stepup and step down transformer ?
pl. explain.
thanks.

 

[zeeshanzia84]

Re: inverter problem

I don´t understand your question completely.

But, maybe there is some rectifier circuit (a few diodes and maybe capacitor/inductor combination to smoothen the ripples) which is converting the AC output of the transformer to DC; which is then being used to charge the battery. Its not necessary to use the same voltage 12V (in your case) to charge the battery. Even if the DC output of the rectifier is higher say 200V it can be used to charge up the battery by using DC-to-DC converters (solid state based) which "step-up" or "step-down" a DC voltage.

An autotransformer can both step up and step down an AC voltage.

HOPE THIS HELPS!

 

[laktronics]

Re: inverter problem

Hi,
It is true, an inverter in strict sense means only a DC to AC coverter. An input DC source is assumed. Battery charger to charge the battery has to be added additionally. Also if you want the inverter to supply power to the load only when mains AC is not present, you have to add necessary switching circuit for this function. A total circuit supporting all these functions is called UPS (Uninterrupted Power Supply) circuit.
Regards,
Laktronics.

 

[nandhu015]

Re: inverter problem

To be clear

There will be a relay which will switch the circuit of secondary (i.e. 230v) side to mains when power is available. Now the transformer will act as charger transformer. Whenever the mains power fails the relay trips and the invertor circuit works to give 230v to the secondary

Regards
Nandhu

 

[melc]

Re: inverter problem

As 90% from the questions from this site, it contain an incomplete description of the inverter and that let the answerer to imagine his own version of the problem.
Completely useless.

Even you didn't look carefully enough and there is more than one transformer, or the batery is not charged from this inverter.

Usually old proffesional inverters with sinusoidal output (not rectangular, not DC output) have two inverting stages, like 220VAC to 12V, 48V or 60V DC and back to 230V AC. This structure is charging indeed the acumulator.

But an inverter 12V DC to 230VAC has absolutely no option to charge the acumulator connected on the input unless a completely charging circuit from main 220V AC is used inside the charger, so then it becomes a 230VAc to 230VAC inverter.

 

[abhay kulkarni]

Re: inverter problem

Yes , as said by nandhu there is one relay but there is no other transformer.
therefore I want to confirm if the same transformer is used for giving 230 vac out put as well as to charge battery when ac mains is present.

 

[padmatv]

Re: inverter problem

Yes, You are right. Nowadays, to cut cost, save on space etc and increase efficiency, The inverters are designed to contain only one transformer with extra tapping for charging the battery while AC mains is present. This also helps in faster switching from Mains to inverter mode as there will be residual core current present and it enhances the faster switching of modes. As FET and MOSFETs are used and in some cases IGBTs are also used for speedy charging and discharging, the primary, secondary and battery charge tappings depends on the designer and ground requirements.

Hope this would clear your doubts.