DSP Sine wave inverter error messsage : "No feedback loop "

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thannara123

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I have the above board ,it is available on our local market ,In which Dspic30F2010 is used .It has two mode inverter and UPS mode .
I have made a lot of inverter with this board .
But now i am experiencing with an error message on lcd "No feed back loop "
I know these problem arise from transformer transformer sensing section . [because if didnt connect the transformer primary to the working board will show these message ]
But here my transformer is working well .

is there anybody use this type of invreter ? , is there any help .

Thanks .
 

nikhilmahasvar said:
Have you connected the transformer drain ? If not it may sense as no feedback. If yes check the feedback section in the LM324.
Click to expand...

transformer drain means connected to the transformer , Yes connected ,And works for one or more second and goes the error "No feedback " then the output will turnoff.
I checked LM324 section is the section from current transformer ?
I changed LM324 also ?
Is there any way the to get the schematic ?

thanks
 

There will be some high value resistors coming from AC output and it will be going to the LM324 I/P pins the output of LM324 will be 2.5V level shifted SW wave. Plz check.
 
nikhilmahasvar said:
There will be some high value resistors coming from AC output and it will be going to the LM324 I/P pins the output of LM324 will be 2.5V level shifted SW wave. Plz check.
Click to expand...

yes there 680k
but the resistor in my board its wrongly 68K
thanks i will change and tell the result

thanks
 

Nothing happens. In which pin of dspic30f2010 sense for the " No feedback " error message
 

LM324 is used as diff. amp just trace the O/P is going to which pin. I you check in dc in meter mode you will get only 2.5V which is the avg. value. If you have a DSO you can get the sw signal at the fb pin. else you may have to chk in AC mode and you will get few milli volts as signal
 
may i check the all(4 o/p) output pin of the LM324 ?
 

Plz chk the datasheet of LM324 check only the O/P of the section in which the FB signal is coming from INV O/P through high value resistors.
 
Two Ac signal coming via high value resistor to the LM324 .These two output of the lm324 is going to the pin second and third pin of the DSPIC30f201
I tried out too much which one i cannot recognize which one is ?
 

From O/p Phase and neutral there will be resistors going to one opamp's inv & non inv pins. Pls chk the output of that.
 
Re: DSP Sine wave inverter error messsage : "No feedback loop "

That pin is 14 th pin of LM324. At the output pin am getting 4.62 volt dc.with respect to ground
Volt mesured by multimeter

- - - Updated - - -

is there any way to find the schematic ?
 

Re: DSP Sine wave inverter error messsage : "No feedback loop "

you should get 2.5V in all O/P pins. In one Opamp of the LM324 there will be a voltage divider which will make 2.5V from 5V I/P plz check that divider your issue will be solved.
 
Yes that was the problem

Thanks ..
 

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