Superseder II

1.2 THEORY OF OPERATION, CONTROL CIRCUITS:(Refer to the circuit board, .nd other circuit sehenatics),..2.L CONTROL CIRCUIT BOARD.rhe contror circuitdigitalBoardcircuitshouses thetoprinciparconirol theanarog andof thetot Enesfi;;seder.currer current W the operating urodea) Analog section:Anplifier ul0yieldingamplifies (x100)an outputthe signalLr _100nV/A from tthe ie,--i0A _ _1.000shunt,contror switctr reverses t|" p?raria, volts) . Theing from charge (posiLive i, the input input)whentoswitch_to maintain ii""rra.ge (negative input),!n" :iI" "utp.rtpotaritV.-'capacitors crz andted during 'cr9.in,;;;;i"Lhe^chargethe short purses genera_Trinpot "p"i"tionpioJ,.r"i..rg R37 is-useia smoothedto ed5ust -io, DC output.yith zero current flow (reset an outputstate).of 0.000v,Anplifier ugandbuffersapplies-itsthe progiaunea outpuL tocurrentintegra[oi-uginput signalruuued via R36, with theviaoutputR24,ifwhere it is,?re programned "ipfifierU10.tiometercurrentRzol for Hain :npu!-;;;""r originates in poten_ping/Discharge crrrr"nt and pofentioueiercurrent. Trre potentioi"t".s nioz for Top_with a dial range fromare s000 toturn devices0'000 to s.o0o.rolt",500, with a vort"g" range ofThe outputs of u10 "oi"""ponding and to 00.0 to so.,-i.p".ug aie -elso thev are fed to the t{onitori:::lt;}:"""onp"t.afor actuar ro prosrammed currenrThe sum .of. -thesi'gnalouputs of ug, which andis theu1o generatesdifference betweenthe erroractuar varue of thethe programnedcurrent..ft;-iit"g""to"and thetere the error rigner amprifend applies ies anditftI conparatorir_Tl:e output of the intllrato"-isu11.about -1.SV at iUout +0.SSVuedium cuii"nts.at reset andis used to calibrate rhe low end (1Anp)",rr""rft:::;":'uof rhecomparatorviaul1 receivessignara.ramp (synchronizedrDL and e1), exienaing withfror-."""Iythe lineof about 3 volts, 'vhich i"'"orp"red0 vori" to a peaktor ug' Tree:"=:.rr,with.isthe output of Integra_scR's on) "-"q.r"r"wavewhen the posiiir"that goesrampt;;-tIu.nrngsignaltheintegrator signar, ind- -i"r"ins cro"""" ii" ,r"g"tivethe line zerorowcrossing).inti I the ra.Dp resets (atL_-- - - - - -;;;;; ;; ; - i i -: -;; ;;; ; ;; ; -;;;; ; - ;;; - ; -: -;;; - ; -