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DRV591

Other Parts Discussed in Thread: DRV591, MPY634

ON THE ABOVE PART

WITH PIN#6 AT A REF. VOLTAGE FROM THE OUTPUT OF A OP-AMP OF +2.50 VDC AND A SINEWAVE RIDING ON THE REF LEVEL

OF 1.25 VAC PK-PK.

ON PIN#7 IS THE OUTPUT OF A OP-AMP THAT WILL BE THE ERROR AMP FOR THE FEEDBACK VOLTAGE AND THE + INPUT OF THE OP-AMP IS AT +2.50 VDC AND THE - INPUT WILL BE WHERE THE FEEDBACK SIGNAL WILL GO .

NOW LETS SAY WE HAVE NO SINEWAVE REF INTO PIN#6 THE OUTPUTS OF THE DEVICE SHOULD BE TWO SQ. WAVES AT THE SELECTED FREQ. AND AS WE START TO APPLY THE SINEWAVE INTO PIN#6 THE OUTPUTS START TO MODULATE AT THE REF.  FREQUENCY.

BOTH OF THE OUTPUT DRIVE SIGNALS AT PINS# 17 AND 24 WILL GO INTO HIGH VOLTAGE HALF BRIDGE DRIVERS AT +200 VDC WHICH WILL BE ISOLATED BY A PLANAR TRANSFORMER  AND THE OUTPUT OF THE POWER TRANSFORMER WILL GO THRU LOW PASS FILTERS AND WE HAVE THE SINEWAVE AT THE OUTPUT VOLTAGE LEVEL .

WE SAMPLE AND DIVIDE THE OUTPUT DOWN TO A REF LEVEL AND FEED IT BACK TO THE - INPUT OF THE ERROR AMP NOW WE HAVE A CLOSED LOOP AND REGULATION,NOW DO YOU AGREE WITH THIS .

AND ALSO THE FREQ SELECTED WILL IT BE DIVIDED IN HALF AT THE OSC INTERNALLY ,ARE LETS SAY WE USE A EXTERNAL CLOCK AT 200 KHZ INTO PIN#4 WILL THE RAMP BE AT 200 KHZ ARE AT 100 KHZ. SEE IF YOU CAN LET ME NO ON THE ABOVE IDEA AND GIVE ME YOUR FEEDBACK PLEASE THANKS,

WILLIE

  • Hi Willie,

    Sorry for the late response. Our experts have been notified and they should respond soon.
  • Hi, Willie,

    Sorry for the delay in getting back to you.

    Your idea seems solid to me, but we have never made a system like this, so I can't tell you for sure.

    Your transformer will need to be capable of the frequency of your sine wave. Just sizing it for the switching frequency won't work.

    As for syncing to an external clock, please review this section of the d/s: EXTERNAL CLOCKING OPERATION

    -d2
  • HELLO MR DAPKUS CAN YOU GO A LITTLE BIT FURTHER ON THE OUTPUT TRANSFORMER , SO ARE YOU SAYING THAT THE SINEWAVE WILL SUPER IMPOSE ITSELF AT THE OUTPUT OF THE XFMR. SO I WONT SEE THE PULSE COMMING OUT FROM THE DRIVER STAGE.

    BECAUSE THE OUTPUT SIDE OF THE XFMR WILL GO TO A LOW PASS FILTER  LET SAY AT 400 HZ.

    ARE YOU SAYING ONCE THE SINEWAVE IS PRESENT ON THE OUTPUT OF THE FILTER THIS WILL ALSO SHOW UP ON THE CORE OF THE OUTPUT XFMR.

    SO THE OUTPUT PULSE WONT BE SQ. WAVES THEY WILL BE SOMEWHAT SINUSODIAL AT THE OUTPUT FREQ.?

  • HELLO MR DAPKUS I HAVE LAYED OUT A SOMEWHAT IDEA CORRECTLY FOR YOU TO TAKE A LOOK AT AND SEE IF YOU CAN GIVE ME MORE FEEDBACK , ALSO PLEASE BE AWEAR THAT YOU CAN CALL ME ANY TIME SOME TIME THAT SETTER TO OBTAIN A BETTER UNDERSTANDING BOTH WAYS , THE DRAWING ATTACHED IS THE FRONT END WITH MOST OF THE CONTROLS ATTACHED I DIDNT WONT OT OVER CROWN THE PAGE AND I TRYED TO MAKE THINGS AS CLEAS AS POSSIBLE, BUT AT THE END THERE IS A PART I WONT TO RUN BY YOU THIS COULD BE A BETTER DEVICE TO USE AND IT COST LESS................. SO WE WILL START WITH THE LOWER LEFT DEVICE THE MPY634 THIS PART I WILL USE AS A WAY TO MAITAIN SOME CONTROL OF THE SINE REF. SIGNAL AND IT ALSO GIVE ME A WAY TO ADD THE FEEDBACK CONTROL LOOP AS NEEDED STARTING WITH X1 AND X2 X1 WILL BE THE INPUT PIN FOR THE SINE WAVE REF THIS SIGNAL WILL BE ADJUSTED TO MEET THE MAX LIMIT ON THE INPUT SIGNAL VIA A 1 MFD CAP INTO PIN#1 PIN 2 WILL JUST GO TO GROUNG TERMINALS Y1 AND Y2 ARE FOR THE FEED BACK CONTROL SIGNAL PIN#6 + INPUT WILL HAVE THE V FER AND I SELECTED IT TO BE APPROX+2.50 VDC COMMING FROM A PRECISION REF DEVICE, NOW AT THIS POINT PIN# V OUT WILL HAVE A SINEWAVE THE SAME AS THE SINE REF ON PIN#1 THE OUTPUT OF THE MPY634 WILL GO TO THE INPUT OF THE DEVICE DRV154 THIS IS A BALANCED LINE DRIVERAND PIN #3 OF THAT PART IS GOING TO GROUND THIS PART OPERATES FROM +/- 5VDC AND THE DRIVE SIGNALS 7&8 AND ALSO 1&2 WILL GO DIRECTLY THE DRV591 THIS IS THE MODULATOR DEVICE ALL PINS FOR THIS PART WILL BE SETUP ACCORDING TO THE SPEC SHEET FOR THE PART, NOW THE OUTPUT FROM THE DRV591, CALLED OUTPUT DRIVE SIGNALS WILL NOT BE UNDER ANY HEAVY LOAD ARE STRESS IAM USING THIS PART MAINLY FIR THE CONTROL FUNCTION, SO THE OUTPUT- PINS 14,15,16,& 17 WILL HAVE A 1 K OHM RESISTOR TO GROUND AND THE SAME FOR THE OUTPUT SECTION THESE DRIVE SIGNALS WILL GO TO HI- VOLTAGE HALF BRIDGE DRIVER DEVICES FOR EACH SIDE TO FORM A FULL BRIDGE LAYOUT.
    THE BUS VOLTAGE FOR THE DRIVER DEVICES WILL BE +200 VDC AND THE DRIVERS WILL BE CONTROLLING HI POWER MOSFET. AT THIS POINT A FULL BRIDGE PLANAR TYPE TRANSFORMER WILL GO ACROSS THE NODE AND THE UNIT WILL SWITCH AT 100 KHZ THIS IS THE RANGE I SELECT BECAUSE ITS A GOOD POINT OF BEING ABLE TO ACHIEVE GOOD DRIVE ORDER AND HAVE VERY LOW SWITCHING LOSSES AT THIS POINT , THE SEC. SIDE OF THE OUTPUT XFMR. WILL GO TO A 4 POLE LOW PASS FILTER NETWORK TO RECOVER THE SINE WAVE REF SIGNAL FROM A RANGE OF 50 HZ TO 1 KHZ MAX. AT A POWER LEVEL OF 1 KILO-WATT RMS.

    NOW THE FEEDBACK SIGNAL WILL BE SAMPLED FROM MULTIPLE PLACES BUT ONLY ONE IS SHOWN ON THE SHEET , SO THIS SIGNAL WILL BE DIVIDED DOWN AND INSERTED INTO THE FIRST OP-AMP LAYOUT. THE OUTPUT VOLTAGE WILL BE ADJUSTED SOMEWHAT TO GET THE REQUIRED OUTPUT, BY THE POTENTIOMETER AND THIS SIGNAL WILL GO INTO THE ERROR AMP AND THE OUTPUT OF THE ERROR AMP WILL GO TO PIN7,... NOW THIS DC VOLTAGE WILL CAUSE / ARE SHOULD COAUE ONCE IT AT THE DC LEVEL OF THE SINE WAVE CAUSE THE SINE WAVE TO DECREASE IN AMPLTD. AND THE SYSTEM SHOULD BE STABLE AND THE LOOP IS CLOSED
    SO NOW AS I LOAD THE OUTPUT SINEWAVE THE DC VOLTAGE WILL TRY TO DROP AT THIS POINT THE AC WILL INCREASE AND TRY TO COMPENSATE FOR THE ERROR AND MAINTAIN REGULATION AND THIS SHOULD CONTINUE UNTIL I RUN OUT OF HEADROOM FOR THE SYSTEM, AT THAT POINT I SHOULD BE IN A OVERLOAD CONDITION AND THE SYSTEM SHOULD SHUTOFF FOR APPROX 3 SEC AND GO INTO A SOFTSTART AND CONTINUE UNTIL THE OUTPUT VOLTAGE IS AT IT PREDETERMINE LEVEL
    IF SHORT, OVER CURRENT ,OVER TEMP ARE ANY OTHER FAULT CONDITION IS STILL PRESENT THE SYSTEM WILL SHUTDOWN
    AND REPEAT UNTIL ALL FAULTS ARE CLEARED, THAN THE SYSTEM SHOULD STAY IN THE HICCUP MODE FOR APPROX 255 CYCLES AND THAN LATCH OFF COMPLETELY, FROM THIS POINT TO RESTART YOU WILL NEED TO DO A POWER CYCLE