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VCA2612 FEED BACK LOOP CONTROLLER ATTN: MS AMY

WILLIE MCCAIN1
Intellectual 380 points
Other Parts Discussed in Thread: VCA2612

OKAY I TRYED TO MAKE THIS MUCH MORE CLEAR......

THE MAIN POINT HERE IS TO CONTROL THE OUTPUT OF A INVERTER USING THE VCA2612 AS THE MAIN SINGLE FEED BACK CONTROL SIGNAL .

SO AT THE INPUT OP-AMP IS A BUFFER FOR THE SINE WAVE SIGNAL THIS SIGNAL IA SET AT 400 HZ AND I CAN ADJ. THE AMPLTD. TO WHAT I NEED AS LONG AS IAM WITH IN THE RANGE, THE OUTPUT OF THE BUFFER WILL GO THRU THE 1 MFD CAPACITOR TO PIN#16 THE SIGNAL CAN BE FILTERED BETTER IF NEED BE BY THE FEED BACK NETWORK AT PIN'S 8&9 THE OUTPUT OF THE LNA AT PIN#6 WILL HAVE A .001 MFD CAPACITOR FOR HI-FREQ. NOISE AND I CAN SET THE LNP GAIN IN AT PIN'S 13 - 15  THE SIGNAL CONTINUE THRU THE DEVICE TO THE VOLTAGE CONTROL ATT. SECTION THE VOLTAGE AT THIS POINT WILL BE THE OUTPUT OF THE FEED BACK ERROR AMP WHICH HAS A + 2,50 V  REF SO WITH NO FEED BACK SIGNAL THE OUTPUT IS AT +3.00 VDC THIS IA 0 DB ATT. AS THE SIGNAL CONTINUES THRU THE PART TO THE PGA AND TO THE OUTPUT BUFFER AMP THIS SIGNAL SHOULD BE WHAT I SET THE REF AT PIN#16 TO BE AND IT'S COUPLED WITH A 1 MFD CAPACITOR AS WELL SO NOW THE INVERTER IS AT THE MAX OUTPUT LEVEL THE OUTPUT OF THE INVERTER GOES INTO A RESISTOR NETWORK ARE VOLTAGE DIVIDER WHICH IS ADJUSTABLE SO NOW WHEN THIS SIGNAL IS APPLIED TO THE ( - ) INPUT OF THE ERROR AMPLTD. VOLTAGE IS FILTERED AND SMOOTH TO A DC LEVEL THIS LEVEL IS THAN ADJUSTED TO BE MORE THAN THE REF +2.50 AND THE ERROR AMP OUTPUT STARTS TO COME DOE  / ARE DECREASE TO MATCH THE REF SO NOW THE SYSTEM IS LOCKED TO THE FEEDBACK SIGNAL AS THE OUT PUT OF THE INVERTER IS LOADED THE OUTPUT WILL TRY TO DECREASE IN AMPLTD. BUT THE ERROR AMP INCREASES TO MAINTAIN THE SAME LEVEL AS THE REF NOW  WE HAVE REGULATION SO AS I DECREASE ARE INCREASE THE LOAD THE UNIT SHOULD  ATE THE OUTPUT VOLTAGE OF THE INVERTER SHOULD BE CONSTANT SO NOW I SET THE OUTPUT AT THE REQUIRED LOAD BY ADJUSTING THE SINE WAVE REF INTO PIN #16 PLUS APPROX 5 % THIS WILL GIVE ME THE ADJ RANGE NEEDED AT THE FEEDBACK  VOLTAGE DIVIDER SECTION SO I CAN ADJ AND HAVE HEAD ROOM FOR THE CHANGE OF NO LOAD TO FULL LOAD NOW SINCE SINE THIS PART IS VERY FLEXIBLE I CAN INPUT . OVER CURRENT SIGNAL , OVER VOLTAGE SIGNAL , OVER ARE UNDER FREQ. CONTROL AND OTHER FEATURES BUY INJECTING THE SIGNALS INPUT PINS 6&7 AND FINIAL ADJ WILL BE TTO SET THE MAX GAIN OF THE INVERTER BE SETTING THE PINS 40 THRU 42 SO NOW WE HAVE PURE SINE WAVE CONTROL AND FINIAL TEST THE UNIT AGAIN BY INCREASING THE LOAD TO MAKE SURE THE SYSTEM IS STABLE AND NO NOISE IS BEING PICKED UP FROM GROUND NODES AND SO FORTH AND SET IT TO MAK AND LET RUN FOR 1 HOUR TO MAKE SURE THE SYSTEM IS TRACKING THRU THE CHANGE IN TEMP. OF THE SYSTEM  AND TO MAKE SURE THE OUTPUT STAY'S AT 115 V RMS.

NOW FOR THE OTHER VGA THAT CAN BE FOR THE 26 V RMS OUT PUT AND I SEE A WAY THAT I CAN DO FORCE CURRENT SHARE WITH THIS PART AS WELL SO I THINK IF MY IDEA IS CORRECT THIS IS A GREAT PART FOR A SOLID FEEDBACK LOOP CONTROLLER  LET ME NO WHAT YOU THINK  AND IF SO I WILL START TO USE THIS PART AS THE MAIN CONTROLLER IN ALL MY INVERTER DESIGNS SO LET ME NO IF I THINKING CORRECTLY..........

THANKS,

WILLIE L. MCCAIN

954-606-5886

  • 0
    TI__Mastermind 49176 points
    Hello Willie,

    This is a duplicate post. Please refer to the original post. e2e.ti.com/.../455700
    I am closing the thread.
  • 0 in reply to Praveen Aroul
    TI__Mastermind 18275 points

    Willie,

    Is there a block diagram or schematic you have for this? If you do not want to post it publicly, please feel free to send me a private message.

  • 0 in reply to Amy Schnoor
    TI__Mastermind 18275 points
    Conversation taken offline.
  • 0 in reply to Amy Schnoor
    Intellectual 380 points

    HELLO MS AMY THANKS FOR THE FEEDBACK THE PART WILL BE WELL WITHIN RANGE BY CONTROL THIS WILL BE ST AT FINIAL TEST, ARE I CAN MAKE A TEST PROCEDURES FOR THE ADJUSTMENT OF THE DIFFERENT SECTIONS.

    NOTE THE THE VCC WILL BE AT +5.00 VDD WHICH WILL BE CONTROLLED BY VOLTAGE REF. LIKE THE REF 01 TO INSURE A STABLE AND CONTROLLED SECTION.

    THE INPUT SINE WAVE REF SIGNAL WILL BE LIMITED TO 1V PK-PK SINE WAVE THIS WILL INDICATE 125 VAC WHICH WILL BE OVER VOLTAGE

    SO THIS WILL GIVE ME GOOD HEAD ROOM FOR THE FEED BACK ADJUSTMENT .

    SO FROM THE ERROR AMP THE OUTPUT WITH NO FEEDBACK SIGNAL THE AMP WILL BE AT MAX THE OUTPUT BUT NOT SHOWN WILL BE DIVIDED DOWN TO LIMIT THE OUTPUT AT OPEN LOOP AT JUST UNDER +3.00 VDC. SO NOW AS THE OUTPUT VOLTAGE IS ADJUSTED TO MATCH THE FDBK. REF +2.50VDC THE OUTPUT WILL START TO DROP TO COMPENSATE , NOW WE HAVE REGULATION......

    SO AS THE OUTPUT OF THE INVERTER IS LOADED THE OUTPUT WILL INCREASE TO COMPENSATE FOR THE DROP IN FEEDBACK SIGNAL .

    THE OUTPUT SIGNAL FROM THE CONTROLLER THE VCA2612 WILL GO TO OUTPUT BUFFERS IF A NEED A LITTLE MORE GAIN BUT STILL NOT TO PUT ANY LOAD ON THE CONTROL SIGNAL THIS HAS TO BE AS CLOSE AS POSSIBLE AT ALL TIMES SO FROM THE 1MFD CAPS THE SIGNAL WILL GO TO OP-AMPS TO OBTAIN DRIVE CURRENT AND FAST RESPONSE TO CHANGE IN OUTPUT.

    BUT NOW WHAT IS THE AMPLTD. OF THE SIGNAL IF I USE THE DIRECT INPUT FROM VCAinP ARE VACinN AT PINS 4 ARE 5 IS THSI INPUT AT 1V PK-PK AS WELL ARE WHAT IS THE MAX AMPLTD IF I USE THE DIRECT INPUTS.