Text preview for : TSV70 MK2 - 6-10.pdf part of Farnell TSV70 Instruction manual (includes schematics) for the TSV70 Power Supply made by Farnell UK.
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CIRCUIT DESCRIPTION
The supply consists of a maLns transformer feeding tsro .reservoir capacitor and series regulator bridge rectifler, systems On the 35 volts 1O amps range the outputs of the two .The systems are paralled by switch S1. serles regulator bank driver inputs are paralled by SIA and driven from the main control cl,rcuit board No. l. On the 7O volts 5 amps range the outputs of the two systems are connected Ln serles. The upper system is drlven from the maln control cl-rcult board No. I, and the lower system Ls drlven from circuLt board No. 2. r .1
35 Volts 1O Anps R,ANGE.
l{alns Transformer lffl feeds !!RI fr6rn a 37V R.M.S. secondary wJ.ndlng. MR2 ls fed from a second 37V R.M.S. secondary. The negatlves of reservolr capacltors C2l and 22 are connected to the negative output terminal vLa fuse F'2, swltch DlD, current monitorlng reslstor R57, and switch S3. The positLve is connected vla serles regulators W17-23 to the positlve output terminal. The negatives of reservoir capacitors C25 and 26 are connected via fuse F3, current monitoring resJ.stor R67 and swl-tch 53 to the negatJ.ve output terminal. The posltlve is connected vla serLes regulator transistors VT24 - 30 and swltch SIC to the posltive outlrut terminal. The lnput bases of \j1lL7 and \/T2{ are paralled by SfA. . The control cLrcult of circuLt board No. I consists of Diodes DI and D2, and Rl which are fed from a 36-O-36V winding on MTl and feed reservolr capacitors Cl and C2. This provides an unstabillsed D.C. supply for'zener diodes ZI and 22 whlch are fed via R2. ZL and 22 provlde a +I5 - O - -IO Volt supply for the reference and controL ampllfler, circuitry. VT4, RII-, 24, RI4 and RI5 comprlse a constant current source which feeds 23, R8 and T2, plns 3 and 18 belng linked externally. 7,3 is the maln reference zener diode and provLdes a +5.1V source wlth respect to Pln I1 whlch ls connected to the + SENSE front panel termlndl. PI and P2 are the coarse and flne voltage controls on "-SENSE[ temlnal the front panel and are connected bctween:the and Pln 17 on control cl.rcuit board No,l..' Pin I7 is connected via R16 to VT5 base. A potentlal dlvlder comprlsJ"ng Pl, P2, A2 and R8 forms the output voltage genslng. The.control anpllfter \215, 6, 8, 9, LO drLves emittar \/1[7. follower Thls drives the serles regulator banlcs W17-23 and W24-3O. The connection belng from Ptn 13 on the circult. board No. I via the thermal- trlp TTl to Pl.n 9 on circult board 2 then via R111 on circuit bbard No. 2 to PLn 1O and from there to the base of \/1117 and via SIA to the base of \l1I24. The control loop acts ln such a sense as to oppose any signal change on VT5 base, 4 -
and hence maLntalns zero voltage between \l1t5 and \i1t6 bases. The output voltage Vo ls therefore defLned as:Vo
=
(R8 + T2). (Pl + P2) ' Vz3 R8.T2
P3 with Overload protectLon |s provlded by \i1IL1 and L2. VT12 base. R33 ls is connected to R49 and to T4 ln parallel When the output connected to the IO volt auxllLary raiL. \l!t|lL |s }ow. current Ls low, the voltage across R49 Ls current lncreases As outPut blased off and \/Tl,2 is blased on. the voltage across R49 increases, and the voltage at VT12 base the base of This contLnues untll becomes nore posJ.tive. \l1lll to begln to conduct. positive to cause \i1I12 ls sufflltently At thls polnt, the voltage across R3O begins to Lncrease until Thls O6 becomls fonpard bLased, and feeds current to \IF'9 base. the drlve into conduction, and ]|ml,ts drlves VT9 fufther avallable to emltter follower VT7 and hence to the series Thls actlon causes a fa1l ln output regulator'transistors. D5 then ceases to conduct voltage, and \l1I5 to be driven off. \IfIl and W12. On further and control 1S now taken over by and. output Lncrease of load, the output voltage falls, of the The output characterLstl'c current renains constant. less than the supply ls therefore constant voltage for loads f Git- set by P3, the front panel current llmlt potentlometer and constanl current for loads in excess of the llmlt. 70 volts 5 amps Ranqe.
wlth swltctr sl ln the 70 volts 5 arnps p.osition, the posLtives of capacltors C2I artd,22 are connected via regulators The negatives of output terminal. infZ-Zf to the iosttive C2L and, 22 "re ionnected vJ.l fuse F2, and switch SID to the of C25 and 26 thgrpositlves 30. ooipot of regulators \i!t24 .1ti" r"golators lqu"T24 30 to the negatlves of C2L are'connecte[ The negatlves of C25 and 26 are connected and, 22 as above. R67-, and switch 53 to the negatlve output fog. F3, reslstor "i. 'J.nput to regulators W17-23 ls as before, and The termlnal. rf:f T24 to 30 is from Pin 12, circuit to regulitors the tnput Thus the two regulator systems are via SlA. board tto.Z, board No.I controls the upper connected in series and circult board No.2 controls the loqter wL7-23, and clrcult regulators W24-3O. regulators The function of cl-rcult board No.l ls the same as on the 35 volt 1O arnp range, and thls ls the nraster voltage and' The control clrcuitry current llmlt- contioi of the suppJ.y. No.2 ls merely to hold the voltage at board of circult output regul.ators w24 - 30 output at half the ternlnal D1O3 and IO4r-and ClOl are a fuIl wave rectifier "oii.g". capacitor system fed from a 36-0-36 volt transformer reseriolr -supplying D.C. voltage fo ?trOl and ?'LOz vLa RlOl' windlng and l- +fO - g - -5 volt supply for cont,rol--amPllfler Thls piovides follower w1o4. of wlo} , Loz, 1O3, anrd emltter ' The conslitlng base of VTIOl VT24- 3O. se rl e s-re g u i a tor s d \ l 1 I 1 O 4 r i ve s to the oulput of thts regulatdr and VT1O2 base ls connected dlvlder R113 and ls connected to the centre of the potentlal
5
n+ SENSE" and "-SENSE" R112 whi.ch is connected. between the at the base of W1O2 is therefore The voltage termj.nals. The action of the voltage. at half the output terminal zero voltage between the bases of VTIOI loop is to maintain YT24 - 30 is and 1O2, and hence the output of regulatot output voltage. at half the termindl controlled by circuit is controlled output voltage The terminal board No. 1; and since switch SIB is closed on this range' by:the output voltage is now specified Vo=
where
R8/A2 =
R8 T2 NF:FIFZ
VT24 - 30 rne volttage vci at the output of regulators by: board No.2 and is speclfied by ci.rcuit is controlled Vct slnce =
F,Ift-jTIT3
=
R113
Vo
Rt13 and R112 are equal Vct
tvo
General: T1O3 and TIO4 are setting scale deflection. the ammeter fuIl potentiometers to adjust setting deflectlon. potentlometers to adjust TlOl and LOz are ful1 scale the voltmeter I
switch which is TTI is a bi-metalllc Thermal trip Its Purpose is to sink assembly. located on the heat on the serles regulator detect excessive temperatures of air flow be caused by obstruction elements, which could system or by fan failure. ln the fan cooling
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gEgTIgN-LVSPECTFICATION MAINS INPUT
50/60 Hz. 2LO, 22O, 23O',24O Volts. 50/60 Hz. Volts. 1O5, 1lO, 115, 12O + lOt of Nomlnal. tolerated mains variation Iulaxlmum :'
OUTPUTCAPABILITY. or Output
fAR$.
O-7O Vo1ts at O-5A. O-35 Volts at O-1OA according selected range. voltage
j
to
the either
is
continuously
variable
over
METERING Two range voltmeter ' 35V F.s.d. and 7OV F.s.d The meter ranges and IOA F.s.d. Two range ammbter 5A F.s.d. by the output range switch to correspond to are controlled the output range in use. LTNE REGULATION. OUTPUT CHANGE FOR lOI I\TAINS CHANGE SHORT TERIII LESS THAN O.OII OR lMV whichever is greatef. LONG TERM (8 HOUR) LESS THAN O.O5I OR 5NV whichever is greater. LOAD REGULATION.
a
OUTPUT CTIANGEFOR ZERO TO FULL IAD CHANGE. SHORT TERM O.OIt OR lmV whichever greater. LONG TERM O.Ost OR 5mV whichever greater. RIPPLE AND NOTSE. LESS THAN,ImV p-p t'leasured at OPERATING TEMPERATURERANGE o-400c. OVERLOADPROTECTION. CONSTANT CURRENT LII,TIT VARIABLE TROM O TO FULL I,OAD CURRENT. DI},IENSIONS. WEIGHT. 43OMMWIDE,
15.93" 26.2 u KGS.
is : is
SOKHz bandwidth.
4IOmm DEEP,
16.14' 57.75lbs. '
L77.8MM HIGH.
7"., rl
7
JtF'
E9EI9N:VSETTING UP PROCEDURE. ACCESS. removing may be gained by first Access to the circultry all the covers, bottom and then wLthdrawlng the rear panel, in the four in slots two sldes and top, which are located extruded bar chassis members. Settlng f) 2l 3) . 4) the Voltaqe Ranges and."Current Limit. Set the CoARSE clockwlse. T2 on clrcuLt
switch to 35v, 1oA. Set the 'RANGETT to fully and FfNE front panel controls
Apply md.ns input to the unlt and adJust outptit. board No. I to give 35.5 volts
anti clockwJ.se, set ful\r LIMIT control Wlth the CURRENT applted to the output terminals' and a short circult board No. 1 to glve zero output adjust T3 circuit Remove the short clrcuit. current. it and adjust Connect a load to the output tbrminals wlth the "CURRENI to give 11 Arnps output current, Adjust T4 circult fully clockwise. LIMIT" control of the unit just the output voltage board No. I rrntil at 11 Amps. Dlsconnect the load. begins to faIl Set the range switch FfNE voltage control Adjust Tl circuit Set the COARSEand to 7OV, 5A. fully clockwise. 7l volts output.
5) 5)
board No. I to give
hand side CLrcuit board No. I is located on the right board and is the circuit of the unit viewed from the front, nearest to the front panel. Settlng 1) the meter full scale deflgctions.
adjust With the RANGE switch on the 7Ov 5A position of the unit by means of the COARSE the output voltage output' to give 7O volts and FINE front panel controls Set T1OI meter. on an accurate external as indicated (fuII reads 70 volts untll the front panel voltmeter scale) adjust Wtth the RANGEswLtch on the 35V IOA positiorl as the output voltage of the unlt to give 35 volts Set TIO2 meter. lndl,cated on an accurate external (full reads 35 vo1ts. the front panel voltmeter untll scale). aPply Wlth the RANGE switch on the 35V lOA position anmeter across the output terminals. an accurate external to give a reading of Adjust the CURRENTLIMfT control the Set T1O4 until meter. lO amps on this external scale) . frortt panel anuneter reads 10 amps (full 8
2l
3)