Text preview for : AAron--BS-310S--service-Manual-ID8331.pdf part of AARON BS-310S Service Manual for Oscilloscope
AARON BS-310s 15Mhz Dual-Scope
also known as Hung Chang OS-610S
Back to : AAron--BS-310S--service-M | Home
rry1qlicntionArFtoN
lSMHz Dua! Trace 0scilloscope
Application/A[RON BS-3{ OS
oscilloscope
is equivalent to
TTM Model 3O3
AARON CORPORATION
2-2, Nishikicho, Kanda
Chiyoda-ku, Tokyo, 101
Phone: 29I-1997
Telex: 222-2341 TTMTYO
TABLE OF CONTENTS
SECTION I INTRODUCTION .....hgEI
SECTION 2 SPECIFICATIONS
SECTION 3 OPERATIONS
3-l INITIAL OPERATION (AC Power Line). 3
3-2 INTERNAL BATTERY OPERATION 3
J-J EXTERNAL DC OPERATION 1
,34 CONTROI.S AND INDICATIONS. 1
3-5 INTERNAL SWEEP AND TRIGGERING 7
34 X-Y OPERATION. 7
3-7 CALIBRATED VOLTAGE MEASUREMENTS 7
3-8 DUAL TRACE WAVEFORM OBSERVATION 7
3-9 TV SIGNAL SYNCHRONIZATION. 7
3-10 ADD & SUB MEASUREMENTS 8
3-l I BATTERY CHARGING. 8
3-12 APPLICATIONS t
SECTION 4 CIRCUIT DESCRIPTION
4-1 OU"ILINESOFCIRCUIT ....... 13
4-2 VERTICAL AMPLIFIER CIRCUIT 13
4-3 HORIZONTAL/TIMEBASECIRCUIT.. .......t4
44 POWER SLIPPLY CIRCUIT t{
44 44<2) Switching Regulator Circuit t.f
44<3) Dc-DcConverterCircuit .....-- 15
. 44-(4) High Voltage Section for CRT and Unblanking Circuit 15
4-4-(5) BLOCK DIAGRAM t5
SECTION 5 MAINTENANCE AND ADJUSTMENTS
5-I GENERAL l6
5-1-(l) Preventive Maintenance t6
5-1-(2) Cleaning I6
5-l -(3)
Recalibration l5
5.2 ADJUSTMENTS AND CALIBRATION
5-2-(l) Power Supply Unit Adjustments . . l5
5-2-(2) Vertical Amplifier Unit Adjustments . . rt
5-2<3) Horizontal/Time Base Unit Adjustments . . n
SECTION 6 PARTS LIST
6-I CHASSIS. 2t
6.2 VERTICAL AMPLIFIER UNIT. .
23
6.3 HORIZONTAL/TIME BASE UNIT 24
64 POWER SUPPLY UNIT. 26
SECTION 7 SERVICING
7-I CIRCUIT DIAGRAM FOR VERTICAL AMPLIFIER I.]NIT 28
7-l-(l) Components Location Diagram D
7.2 CIRCUIT DIAGRAM FOR HORIZONTAL/TIME BASE IJNIT .
30
7 -2-(l) Components Location Diagram 3l
7.3 CIRCUIT DIAGRAM FOR POWER SIJPPLY I.]NIT. 32
7 -3-(l) Components l,ocation Diagram l_r
SECTION I INTRODUCTION
The Model BS-3t0Sisadual trace,battery-operated, l5MHzPortableOscilloscopeof rectangular CRTwith internal graticule.
Weight only 4.5kgs. and 1 l3(H) x 2B(fD x 298(D) mm in size, it is an ideal oscilloscope for the field service.
This BS-310S offers 2m V/DIV sensitivity, automatic selection of chopped or alternate mode, plus automatic selection of
TV line or frame display. It further provides the choice of DC, Battery or AC line operation. Internal rechargeable batteries
which provide 2 hours continuous operation.
The portability and performance compatibility realized by the BS-310S make it most attractive for use in "ON-SITE"
maintenance applications; for example Telecommunication equipment, Computers, Marine and Airborne system, Industrial
control equipment, Test equipment on cars, trains, etc.
,I
,I' *
rry
!
-1-
SECTION 2 SPECIFICATIONS
VERTICAL DEFLECTION
Factor
Deflection 2mV to / DIY on 12 ranges in l-2-5 step with hne control.
10V
Bandwidth DC: DC to l5MHz(-3dB)
AC: l0Hz to l5MHz(-3dB)
Risetime 24nw,
Overshot Less than 3%
lnput Impedance lMp shunted dy 20pE+3pF
Operating Modes CH-A, CH-B, DUAL, ADD and CHOP
Chop Frequency 200KHz approx.
Channel Separation Better than 60dB at lkHz.
CH-B Polality CH-B can be inverted
TIMB BASE
Type Automatic and triggered. In automatic mode, sweep is obtained without input signal.
Sweep Time 0.5p sec to 0.5sec/ DIV on 19 ranges in l-2-5 step with fine control and X-Y.
Magnifier x5 at all ranges
Linearity Less than 3%
TRICCERING
Sensitivity INT: I DIY or more
EXT: I Vp-p
Source INT, CH-A, CH-B' or EXT
Slope Positive and Negative, continuously variable level: Pull for AUTO
Range 20Hz to l5MHz
TV Sync Vertical and Horizontal Sync separator circuitry allows any portionof complex TVvideo waveform to
be synchronized and expanded for viewing.
TV-H(Line)andTV-V (Frame)sync are switched automatically by SWEEP TIME / DIV switch.
TV-V: 0.5sec / DIY to 0.lmsec/ DIV.
TV-H: 50,12 sec/ DIV to 0.5p sec/ DIV.
HORIZONTAL DBFLECTION
Dellection Factor 2mVto l0Y/ OIV on 12 ranges in l-2-5 step with fine control.
Frequency Response DC to lMHz
InputImpedance lMg shunted by 20pF+3pF
Max Input Voltage 300V DC+AC peak or 600Vp-P
X-Y Operation X-Y mode is selected by SWEEP TI]I{E / DIV switch
CH-A: Y axis
CH-B: X axis
OTHER SPECIFICATIONS
CRT 95mm tube(approx. l.5KY)
CalibrationVoltage 0.5Yp-pr+ 5%, lKHz Squre Wave.
Power Requirements AC: 90- l30Y or 180-260V; 48-440H2
DC:11-30Y;7.2Y4
Battery: Ni-Cad Battery(up to 2 hour operation)
Charging Time: 6hours(Scope not operated)
l6hours (While Scope operated)
Weight 4.5kgs(5.5kgs including battery)
I 13(H) x 223(W) x 298(D)mm
-2-
SECTION 3 OPERATION
3-I INITIAL OPERATION
Inspect the carton for serious damage which might have caused the failure of the instrument during transportation. And
inspect the instrument itself. If damage is noted, notify the agent you bought from before making any operation.
INITIAL AC OPERATION
1. Prior to any kind of operation of the instrument, proceed as follolvs to get familiarized with the instrument.
a) Set the POWER switch to OFF.
b) Turn all the three POSITION controls to mid-position.
c) Turn INTENSITY control to mid-position.
d) Push the PULL 5X MAG control for normal.
e) PuIl TRIGGERING LEVEL control for AUTO.
0 The rest of the controls remain at any position.
g) Check the line voltage.
2. Connect the AC line cable into the AC receptacle on the rear panel of the instrument, and plug into an AC power
outlet. Then the LED BATTERY CHARGE indicator is lit up in red, which means that the set is charging the internal
Ni-Cd battery. (Power source; AC (or EXT DC) position)
3. Turn POWER to ON. After approximately 20 seconds, trace lines appear on CRT screen. If no trace lines appear, rotate
INTENSITY clockwise till trace lines are easily observed.
4. Adjust FOCUS and INTENSITY controls for clear trace lines.
5. Readjust Vertical and Horizontal POSITION controls for locations required.
6. Connect a probe (10:1) to INPUT of CH-A and hook the tip of the probe to CAL 0.5Vp-p output.
7. Rotate CH-A Vertical attenuator VOLTS/DIV switch to l0mV/DIV and turn the VARIABLE on the same axis clock-
wise to detent. Turn TRIGGERING SOURCE to CH-A. Then a square-wave of 5 divisions is displayed on the screen.
8. Readjust INTENSITY, FOCUS for clearer display.
9. RemoveprobetipfromCAL0.5Vp-poutput.Now,theoscilloscopeisreadyforobservationofwaveforms.
3.2 INTERNAL BATTERY OPERATION
1. It is required to charge up internal battery to lull before operation. It takes only 6 hours to recharge while the instru-
ment is not in use. Whereas, while the instrument is in use, the recharging takes 16 hours to reach the full level of the
battery.
2. RECHARGING
Connect the AC power cable to AC outlet and to AC receptacle of the oscilloscope. Then recharging automatically he-
gins whether POWER switch is ON or OFF. When it is turned to OFF, recharging requires only 6 hours, andwhen
ON, it takes l6 hours for full recovery. Whenever the battery is charged, BATTERY CHARGE indicator changes its
color lrom red to green. Then automatically trickle charging starts to maintain the lull charged level.(Power source; AC
(or EXT DC)position)
3. OPERATION
Turn POWER SOURCE slide switch found on rear panel to BATTERY (INT), and operate the same way as AC opera-
tion.
-3-
SECTION 3 OPERATION
3.3 EXTERNAL DC OPERATION
Make sure the EXT DC INPUT receptacle is correctly wired to its polarities (+ & -). The DC external source could be any
type of I lV up to 30V, withstanding the current drain of 7 .2YA. The wide voltage variation range means the fluctuations
in-between would not ill-effect the operation of the instrument. The EXT DC source will not charge the internal battery.
34 CONTROLS & INDICATIONS
I. VERTICAL INPUT
Vertical input terminal for CH-A.
2, AC.GND. DC
Vertical input couplingfor CH-A. In AC position, the DC componetof input signal is blocked by capacitor. InGND
position, the input terminal opens and the input of internal amplifier is grounded. In DC position, the input terminal is di-
rectly connected to the amplifier and all components of input signal are displayed.
3. MODE
CH-A: Waveforms of CH-A are displayed.
CH-B: Waveforms of CH-B are displayed
DUAL: In the range from 0.5sec/ DIV up to lmsec / DlY, both channels are chopped at about l00KHz.
In the range from 0.5msec / DIV up to 0.5p sec / DIV, both channels are switched alternately..
ADD : CH-A and CH-B signals are added.
CHOP: This is chop cinly mode all throughthe sweepranges.
4. VOLTS / DrV VARTABLE
5. VOLTS / DrV
Vertical attenuator for CH-A. The scale is graduated in voltage per "DIV"
CRT screen area. of
Calibrated voltage is indicated when VAR,IABLE is turned fullyclockwise. Set this cnotrol for proper waveform according
to the input'voltage used. Selectableinl2 calibratedranges from 2mY / DIY to 10V / DlV.
6. VERTICAL POSITION
Vertical position adjDster for CH-A.
7. HORIZONTAL POSITION
Horizontal position adj uster.
8. SWEEP TrME / DrV
Horizontal sweeptime selector. It selects sweeptimes of 0.5p sec/ DIV to0.5sec / DIY in 19 calibratedsteps. X-Y
operation is possible by turning the knob fully clockwise to CH-B.
Change over between CHOPand ALTERNATEis also accomplished automatically by this selector in DUAL MQDE.
9. SWEEP TIME / DrV VARIABLE
IO. EXT. TRIG
Input for external triggering signal.
1I. CAL
Calibration voltage terminal. Calibration voltage is 0.5Vp-p of about lKHz square wave.
12. BATTERY CHARGE
Indicates the charging and charged.
When battery is chaged enough for use this lamp changes from red to green.
I3. TRIGGERING LEVEL
LEVEL control adjusts sync phase to determine the starting point of sw@p on the slope of displayed waveform.
PULL AUTO
By pulling LEVEL knob toward you, auto-sweep is effected; the sweep is set in free-running state even when no input
signal is applied, with trace line displayed on CRT.
With trigger signal, triggered-sweep is effectedwhere sync level is adjustable. Whensync level is deviated, the sweep
is set in free-running state.
I
SECTION 3 OPERATION
FRONT VIEW
14. POWER ON LAMP
I5. SYNC
Sync polarity selector. At the " t " position of rhe switch. sweep is started with positive slope; at the " " position, the
sweep is started with negative slope.
I6. SOURCE
Sync source signal selector switch;
INT : Mixed signal of CH-A and CH-B becomes sync source
CH-A : CH-A vertical input signal is used as sync signal.
CH-B : CH-B vertical input signal is used as sync signal
EXT : The signal applied to EXT TRIG is used as sync signal
11. GROUNDED TERMINAL
18 POWER SWITCH
Turns power on or off. AC power line connected,normal chargingBwhile this switch is onandquickchargingwhenturn-
ed off.
19. FOCUS
Focus control to obtain optimum waveform display.
20 INTENSITY
Adjust the brightness ol waveform for easy viewtng.
21. TRACE ROTATOR
The earth magnetics effect the trace line Rotate this with a screw driver for proper trace line
22 PULL INVERT
When pulled, CH-B is inverted, and this accomodates ADD ro SUB mode.
-5-
SECTION 3 OPERATION
REAR VIEW
.!.) voLTS / DrV
Same as 5. for CH-B
VOLTS / DIV VARIABLE
Same as 4. lor CH-B
25 VERTICAL INPUT
Same as 1. for CH-B
26 AC-GND-DC
Same as 2. for CH-B
POWER SOURCE
AC(or EXT DC): AC operation and DC operationfrom 1lV to30V DC
BATTERY(INT): Internal battery operation.
28 AC POWER LINE RECEPTACLE
90V-130V AC or l80V-260V AC, 40Hz to440Hz
29, EXT DC
With use of EXT DC INPUT receptacle, connect llv to 30V DC source for operation. Whenthe External DC plug
is inserted, Priority is given to EXT DC source even other sources are connected. Power consumptionis maintainedthe
same level.
30. BATTERY COMPARTMENT
Remove the right-side rwo legs on rear panel and take off the four screws for opening BATT COMPARTMENT. Pull
olf the connector ol battery before taking out battery. Installation of battery should be done vice versa.
-6-
SECTION 3 OPERATION
3.5 INTERNAL S}ryEEP AND TRIGGERING
L TRIGGERING LEVEL knob selects either AUTO lor automatic recurrent sweep or nonnal triggering sweep operation.
PULLAUTO provides automatic recurrent sweep in the absence of input signal for triggering.
2. In the presence of input signal for triggering, no difference is found between AUTO and normal modes. The point on
the trace at which sweep triggering occurs is selected by adjusting TRIGGERING LEVEL control. The main purpose
of TRIGGERING LEVEL control is to obtain a stable waveform display.
3. Set SYNC switch to NORM(+) position if the sweep is to be triggered at a point on the positive goingportion of the
display waveform or to the (-) position if the sweep is to be triggered at a point on the negative going portion of the
waveform.
4. Most waveforms can be observed by using INT, CH-A, CH-B as internal TRIGGERING SOURCE. When an external
triggering source is required, turn to EXT and apply the triggering signal to EXT TRIG input.
5.. For normal operation the magnifing switch, 5X MAG is pushed-in to operate without magnification. If magnification of
a waveform is desired, pull 5X MAG switch out. That will expand the sweep and waveform to be observed horizontally
by a factor of 5.
6. Set sweep TIME/DIV switch and VARIABLE control for the desired number of wave cycles to be displayed.
NOTE'] USING THE 5X MAG POSITION, THE TRACE LINE BECOMES DIMMER BECAUSE OF INCREASED SWEEP
WHICH CAUSES LESS ELECTRON TO EMIT LIGHT FROM THE PHOSPHOR LAYER ON THE CRT FACE.
3-6 X-Y OPERATION
For some special cases, this instrument is specially designed for easy X-Y application. Simply turn SWEEP TIME/DIV switch
to CH-B. Then all CH-B functions work as horizontal amplifier, whereas CH-A remains as vertical amplifier.
3-7 CALIBRATED VOLTAGE MEASUREMENTS
Peak voltages, peak-to-peak voltages, DC voltages and voltages of a specific portion of a contplex waveform can be measured
using this instrument as a voltmeter. Voltages can be measured whenever waveforms are observed using either CH-A or CH-B
inputs. Proceed as follows;
1. Set VARIABLE control fully clockwise to CAL position, then set VOLTS/DIV control to display the waveform in
proper size to be observed. Vertical POSITION controls may be turned to obtain division reference.
2. For DC or complex signals, set the input switch to GND, and adjust the vertical POSITION control to a convenient
reference level. Set the switch to DC and observe the amount of deflection. A positive voltage will deflect trace up-
wards; a negative voltage will deflect the trace downward. To calculate the voltage reading, multiply the vertical deflec-
tion (by division) by the setting of the VOLTS/DIV switch.
INoTE-l WHEN A PROBE (r0:l) rS USED, THE WAVEFORM DTSPLAY IS ONLY ri 10 OF THE ACTUAL VOLTACE
MEASURED.
3-8 DUAL TRACE WAVEFORM OBSERVATION
MODE switch to be turned to DUAL. Other procedures are in the same manners as mentioned above.
3.9 TV SIGNAL SYNCHRONIZATION
Set TRIGGERINC SYNC to TV (+ or then specially designed circuitry provides easy triggering lor complexed TV frame
-),
and line signal. TV frame and line waveform are easily obtained by simply tuning SWEEP TIME/DIV control.
-7 -
SECTION 3 OPERATION
3-10ADD & SUB MEASI.REMENTS
to ADD, added waveform ol CH-A and CH-B is displayed.
Sinply turn MODE switch
Withthis MODE at ADD position, subtracted waveform is obtained by pulling PULL INVERT knob whichinvertsthe
Polarity of CH-B.
}11 BATTERY CHARGING
The Charging circuit in the power supply section operates from either 90V to 130V or 180V to 260V normalACpower.
The internal charging circuit works in two ways.
l When the instrument is switched on, the normal charge circuit charges the battery with l/10C. The frontpanelBAT-
TERY CHARGE indicator changes from red to green when the battery is fully charged, and normal charging is auto-
matically changed to trickle to maintain the full charged level. Recharge requires l6 hours.
2. If the instrument is switched off, the internal quick charge charges the battery with approx. ll4C and lull recharge in
this case takes 6 hours.
3. Whenever the internal battery is charged up to full, charging changes to trickle from either quick or normal charge.
NoTEI THE EXTERNAL DC SOURCE WILL NOT CHARGE THE INTERNAL BATTERY.
3-12 APPLICATIONS
This is a dual trace oscilloscope which has full capability of single trace mode. Thanks to the dualtrace functions,
various effective measurements are feasible.
[srNclp-rn ACE APPLICATIoNS]
Either Channel A or Channel B canbe usedfor single-trace operation. Channel Ais referredtohereunder for
Set controls:
AC.GND.DC. AC
MODE CH-A
SYNC NORM+
SOURCE INT or CH-A
PROBE to CH-A INPUT Jack
(l : l)
Connect the tip of the probe to the poi nt in the circuit where the wave form is to be measured, and its ground clip to the
chassisor the ground part.
@\UrIION!!T] THE PEAK-TO-PEAK VOLTAGE AT THE POINT OF MEASUREMENT SHOULD NOT
EXCEED 600 VOLTS.
-8-
SECTION 3 OPERATION
3.I2.( I)AC VOLTAGE AND FREQI.,IENCY MEAST,RENIENT
/ DIV VARIABLEs @, @ and SWEEP
When measuring voltage and frequency, set VOLTS TLME / DIV VARIABLE
@at their calibrated detent points (clockwise).
(EX) The signal displayed on the CRT is : Fig. I
\ \ VOLT / DIV...... at 2V
SWEEP TIME / DIV...... at 5msec
--r 4Drv (b)
Fig. 1
l-- or,, --]
(a) Peak voltage . 2Y / DIV x2 DIV: 4 volts
(b) p-p voltage . 2Y / DIY x4 DIV: 8 volts
(c) Effective voltage. Peak voltage =2:4(V)x 2
: 2.828 volts
(d) Fre4uency (Hz) . I / Time (second)
** Time:Number of DIVs for I cycle x
value of SWEEP TIME / DIV
Therefore, the Fig I is :
Frequency:
5msec X 4 (DIV) 20m sec
50 Hz
The input of this oscilloscope is lMg shunted by 20pF capacitance. Whenthe probe is usedin l0: 1
attenuation, the irnpedance becomes lOM O shunted by l5pF. Then the voltage reading must be multiplied
by 10.
3.12.(21DC VOLTAGE MEASUREMENT
AC-GND-DC being at AC position, only AC or AC component was displayed on the CRT screen. For DC Measurement,
set the switchto GND and pull the TRIGGERING LEVEL knob@for atrace line, which must be positioned at a@rtain
place as O volt reference.
After that, turn the switch to DC. Then the trace line shifts up or down. The value of movement is the DC voltage.
DC voltage : Shilt (DIV) x VOLTS / DIV
When the trace line shifts up-ward, the polarity is ( f ), and down-ward is ( -).
-9
OPERATION
SECTION 3
3.12.(3),dM MODI.LATION MEASLREMENT
introduced'This method is applicable
There are various ways of measurements, but herein this manual the envelope methodis
when the carrier frequency is withinthe frequency bandwidth of the oscilloscope. See Fig. 2
(%): AB
_1
B Mod. 100
A+ts
I -)
Fig.2
3.12-1 4I DUAL.TRACE APPLICATIONS
MODE switch beingturnedto DUAL, both Channel A and Channel B works simultaneously.
Then, comparison of two relative signals are easily compared such as 1evel, waveforms, phase, etc.
3-I2-(5) LB\tsL COMPARISON
(EX) OUTPUT / INPUT of an amPlifier
t zaTa-j
OUTPUT
Fig. 3
With the connections of the Fig. 3, Set the displays of CH-A and CH-B the same (POSITION controls could be adjusted to
place CH-B waveform onto CH-B). Thenthe difference betweenredings of CH-A VOLTS / DIY and CH-B's is the gain
of the amplifier.
caused in the
If the two signals do not match each other even variable controls are adjusted, the difference is the distortion
amptifier. Then, simply turn rhe MODE switch to ADD and putl the CH-B position knod for invert (SUB MODE), for
viewing only distortion. When thereis nodistortion originated in the amplifier, a straighttrace line is displayedinSUB MODE
- l0-
SECTION 3 OPERATION
3.12.{.6l. REPAIRING STEREO SYSTEMS
Every stereo equipment has two symmetrical amplifier circuits.
So, simultaneous comparison of the same stages makes it so easy to locate defective point.
}rz-l7lTv SERVTCTNG
Triggered oscilloscope is indispensable. This model has the very convenient TV SYNC circuits of TV-V(Frame) and TV-H
(line) for accurate synchronization to view VIDEO SIGNAL, BLANKING PEDESTALS, VITS and Vertical / Horizontal
SYNC PULSES.
}12.(8I COMPOSITE VIDEO ANALYSIS
The most important waveform in TV servicing is the composite signal consisting of the video signal, the blanking pedestals,
and sync pulses. Fig 4 and Fig. 5 shows composite signals synchronized with horizontal sync pulses and vertical blanking
pul ses.
VIDEO
Fig.4 Fig. 5
HORI AL VERTICAL VERTICAI.
SYNC PULSE BLANKING SYNC BLANKINi
PULSE PULSE
- ll -
SECTION 3 OPERATION
3.12.19]' MEASI.]REMENT OF FREQUENCY BY X.Y
Simply turn SWEEP TIME / DIV switch to CH-B for X-Y operation. Then CH-A becomes Y axis and CH-B X axis.
Connect a standard frequency signal to CH-B and unknown signal to CH-A. Lissajous' figure is displayed on the
screen as shown in Fig 6.
Standard signal frequency: Unknown signal frequency
((8 )) 1
-:
2
I
I
1-
2
I
/ros, l:1 6l
3.12.(10)PHASE MEAST.,REMENT
In X-Y function, apply twosignalsi to each CH-A and CH-B. Calculate according to the formula.
slNE /:R
6: PHASE
-12-
SECTION 4 CIRCUTT DESCRIPTION
Fig.6 shows the BLOCK DIAGRAM of the oscilloscope. The circuit is shown in the circuit diagram given at the SECTION 7
of this Manual.
4.I OUTLINES OF CIRCUIT
This oscilloscope is provided with two identical input attenuators and two vertical pre-amplifiers. The input is attenuated
to the required level, amplified at the pre-amplifier, and led to the switching circuit, a part of the signal being separated as
trigger signal. The switching circuit consists of diode circuit and mode control logic circuit, which accomplishes the change-
over between CH-A and CH-B, or DUAL as well as trigger signals.
In DUAL-TRACE operation, CHOP (at 200KHz) and ALTERNATE are automatically selected by SWEEP TIMEiDIV
switch. The input after proper switching is fed to the output amplifier and is finally applied to the vertical deflection plate
of CRT. At the same time the trigger signal out of mode control logic circuit, or the external source, will be clock pulses
that drive the saw-tooth generating circuit after being amplified at the trigger amplifier. The saw-tooth wave generated by
the clock pulse is applied to the horizontal deflection plate of CRT, after being amplified.
This oscilloscope is operated by the three different power source; AC, EXT DC and Battery. In AC operation, the Battery
is always being recharged whenever a line cord is connected. All voltages are supplied to the DC to DC converter connected
with the Switching Regulator. Highly stable and elficient operation is made possible by the use of this Switching Regulator
which controls the pulse width to supply constant output level, free from fluctuations. The converter output is supplied to
each section as the power source. The high voltage for CRTisalsobeingsupplied,afterbeingfurtherstablizedthroughthe
feedback-type constant voltage circuit.
4-2 VERTICAL AMPLIFIER CIRCUIT
The vertical input signal fed from the BNC input terminal is controlled by the AC-GND-DC switch and applied to the lst
attenuator, where 1/10 step (20d8) attenuation takes place. The out of input protection circuit Ql(Q25) is fed to the
DUAL FET through high input impedance. DUAL FET is well DC balanced against temperature variation. The output is
then applied to the 2nd attenuator composed ol lCl(lC2). The 2nd attenuator composed of ICI(lC2). The 2nd attenuator
makes the selection of lll,l/2.5,1/5 of ICI(IC2). Alter being DC balanced, through VR1,3,4(VR7,
steps. modilying gain
9, 10), the output signal is fed to the diode switching circuit composed of D2-5, l6-19 as well as to the trigger amplifier
made of Q7,8,31,32.
The mode logic circuit which is controlled by the MODE switch, makesthe selectionof dual-trace,single-trace,CHOPand
ALT possible. Dual-trace operation is obtained by the trigger select logic circuit driven by TRIG SOURCE switch, while the
vertical MODE switch works prior to TRIG SOURCE switch and selects a proper trigger signal for single-trace operation.
In X-Y operation, controlled by the SWEEP TIME/DIV control, CH-B signal is supplied to the trigger amplifier and fed to
the horizontal amplifier as the X signal.
The vertical signal through diode switching circuit passes the limiter circuit of Qll, l2 and D6-9 to obtain the adequate
level, and then is fed to the output amplifier composed of Q15-24. The output obtained is sufficiently amplified by the
feedbacktype amplifier with the constant current circuit (Q19, 20,23,24). This amplifier is equipped with the booster
(Q21,22) for high frequency corrtents to obtain flat response signals. The signal is then fed to the vertical deflection plates
of CRT.
- 13 -
SECTION 4 CIRCUIT DESCRIPTION
4.3 HORIZONTAL/TIME BASE CIRCUIT
Time Base circuit consists of trigger section, the saw-tooth generating section and amplifier section. The output from
trigger select circuit is led to sweep X-Y select circuit (Q7-10, 19). This select circuit works as the internal trigger amplifier
and the saw-tooth wave antplifier in normal operation, and as the amplilier for CH-B signal in X-Y operation. The internal
trigger signal is being amplified by lC2 and then led to CMOS schmidt circuit (lc3b, c). The external trigger signal is
rJirectly fed to ICl. With TRIG SOURCE switch set to TV, IC output is connected to TV sync separator (Q1,2) to obtain
horiz.ontal sync signal (TVH) or vertical sync signal (TW) and to supply it to schmidt circuit. Changeover between TVH
and TVV is autor.natically acconrplisheci by the SWEEP TIME/DIV switch. The signal in the schmidt trigger circuit is shaped
into square waves and becomes clock pulses lor sweep control gate (lC5). The clock pulse is also supplied to auto sweep
(Q10. IC4c. d). With no trigger input, the output of the auto sweep circuit becomes low level, and therefore sweep control
gate starrs automatic sweeping. With triggering input, or supply of clock pulse, the output of auto sweep circuit becomes
high level and the gate F.F. is inverted by the clock pulses and the Miller integrator becontes charged. When the gate F.F. is
inverted. and sets Q4 to OFF, the Miller integrator determines the sweep tinre by the C/R tinle constant selected by the
SWEEP TIME/DIV switch to obtain saw-tootli waves of excellent linearity. When the output lrom the Miller integrator
fully rises. the Hold-off F.F. is inverted and the sweep stops for the time determined by the Hold-offltime constant. When
the Hold-off time passes. the next clock pulse is set in standby mode and thereby the sweep teturns to the originaJ status.
The output ol this Miller integrator passes through sweep X-Y select circuit and is fed to the horizontal amplifier (Q11-15).
ln this arnplifier. by use of Q13 and MAG X5 switch, sweep time is expanded by factor of 5. With SWEEP TIME/DIV
switch set to X-Y position. sweep X-Y select circuit is switched to separate the Miller integrator from the horizontal anlpli-
f ier and then the vertical Ctl-B input is applied as l.rorizontal input amplilier. In CHOP operation, blanking effects are given
with the Lrse ol the horizontal Q output and CHOP signal generator. In ALT operation. the ellects are given by Q output.
Tlie output lront ntultivibrator ol ICI is shaped to obtain the calibrating voltage output. The variable resistor of VR1 is used
to adjust the output level of 0.5p-p.
4.4 POWER SUPPLY CIRCUIT
4-4-(t) BATTERY CHARCTNG CIRCUIT
Power transformer, rectilier, ripple lilter and battery charger are equipped belore POWER switch, and these circuits are
operatr.d whenever AC line cord is connected, whether POWER switch is turned ON or OFF. The major elements of the
battery charger (Ql-8) consist of constant current regulator, normal and quick charge circuit, comparator (overcharge
protection circuit) and LED indicator. When POWER switch is turned OFF, Q3 is set to OFF and constant current with
l/4C (300mA) is supplied.liPOWER switch is turned ON, 10V DC is detected and Q3 is set to ON, starting l/10C(120mA)
charge. In either case, current is supplied to the red part of the two-color LED while the battery is charged. Charge reaching
the fixed level. the comparator (Q7, 8) turns Q7, 4 ON, letting current flow to the green part of LED. At the same time,
bias current of Q2 is decreased and trickle charge of 1/50C (24mA) starts.
4-4-(2) SWTTCHTNG REGULATOR CTRCUTT
AC power, aiter rectified, is led to the Switching Regulator. Switching signal pulse width is controled by input DC voltage,
which is the ieed-back lrom its DC output. Therelore this DC output is very well regulated and drives the next converter.
When input voltage drops below the lower-operation-level of this circuit, comparator (lC3c, d, lC2a) turns switching
circuit to OFF, and seli-triggered multi. (lC3a, b) starts oscillating, making POWER LED lamp flicker.
-14-
SECTION 4 CIRCUIT DESCRIPTION
4-4-(3) DC TO DC CONYERTER CTRCUTT
This converter is being driven by self-oscillation circuit (lC2c, d). The oscillated signal drives Ql8, Ql9 in turn, and the
inconsecutive DC power source is supplied to the primary side of L5 transformer. The currents in the primary side of
L5 alternate one after another, and square wave power is generated in the secondary side. Transistors (QI8, l9) are lully
protected by diodes (Dl 5 - I 8).
4-4-(4) HrGH VOLTAGE SECTION FOR CRT & LJNBLANKING CIRCUIT
An acceleration voltage of about -1.5KV DC is required for operation of CRT. This voltage is generated by DC to DC con-
verter and stablized through the feedback-type constant voltage circuit, to protect from the change in high voltage due to
increased luminance, etc. The blanking signal obtained from Sweep Time Section is amplified in the Cascade Amplifier
(Q23-25,35) keeping the fast rising characteristic, supplied to the DC regenerative circuit (D23-25,35) and finally fed to
the grid of CRT.
CHA MODE
PRE AMP
CONTHOL LOGIC
CH.A
TRiG AMP
/VERTI CAL \
\ sErrcr,/
o9-24,r5 |
CH, B /TRIGGFR \ 0|.!
TRIC AMP \ sgrEcr./ c r-a
16
I
I
---'-
VOLTAOE
REGULATOR
SW I TCHI NC
REGULATOR
D5-r0 l.t2
Fie. 6
- 15 -
SECTION 5 MAINTENANCE & ADJUSTMENTS
5.I GENERAL
This section contains infonnation for preventive maintenance, adjustment and calibration .
s-l-(l) PREVENTM MATNTENANCE
Preventive maintenance consists of periodic cleaning, and recalibration of the oscilloscope. It should be performed on a
regular bases to keep the instrumgnt in its best operational and appearance condition.
s-l-(2) CLEANTNG
Accumulation of dirt, dust and grime should be removed whenever they become noticeable. The frequency of cleaning
is largely dependent upon the environment in which the instrument is used. Dirt on the outside covers may be removed
with a soft cloth moistened with a diluted household cleaning solution.
s-l-(3) RECALIBRATTON
Recalibration ol the instrument at regular intervals will assure that measurements within the accuracy specification. It
is recommended that the instrument be recalibrated alter 1000 hours of operation, or twice a year. The calibration
procedures are provided in the latter part of this section of the manual.
5.2 ADJUSTMENT AND CALIBRATION
Most of the problems resulting in a mallunction will be a defective component or a mechanical defect. Verify that the
problem is not due to an incorrect switch position. The CRT display can be a valuable aid in pinpointing the area of many
problems. The defect of any of the amplifiers, triggering circuit will be noticeable on the CRT.
5-2-(l) POWER SUPPLY UNrT ADJUSTMENTS
Some problems may result severe loading on the power supplies. The power supply unit for the BS-310S comprises
a DC-to-DC converter. The normal operating frequency of the converter is approximately llKHz. Modilying pulse width
with the change ol loads, this converter assures the constant voltage supply. When the secondary voltage of the converter is
incorrect, remove the P3 and P4 connectors olthe Power Supply unit for checking.
I . VOLTAG E ADJ USTMENTS . . . . When voltages are out of atljustments, care lul realignnrents may be neces-
sary.
a. 100V Adjustment Adjust VR9 to obtain l00V t0.5V between the 2nd pin on connector
P3 and the ground.
b. l 4KV Adjustment Adjust VR7 to maintain the voltage within -l.4KV between the 2nd Pin
on Corrnector P2 and ground.
EUfMNI] EXCESS VoLTACE MAY DAMAGE CRT oR SHoRTEN CRT LIFE.
2. ADJUSTMENT OF RECHARGINC CIRCUIT . When the length ol time lor charging and discharging
the battery is questionable. Adjustment ol FULL-CHARGED VOLTAGE LEVEL may be necessary.
NoTE FLILL-CHARGED VOLTAGE LEVEL IS SUBJECT To AMBIENT TEMPERATURE.
Adjust VR1 in accordance with the algebraic equation below.
reAUT'ON![I ACCURATE ADJUSTMENTS ARE REQUIRED IN oRDER To AVoID PoSSIBLE DANGERS FRoM
BATTERY DUE TO OVER-CHARGE OR IMPERFECT CHARCE. AND TO MAINTAIN THIS INSTRU-
MENT'S IN.SPEC OPERATIONS FOR A LONG TIME.
FULL-CHARGED VOLTAGE LEVEL (V)
(V) = ls.so (0.04 X x'C) ** xoC . .' . . AmbientTemperature
-16-
SECTION 5 MAINTENANCE & ADJUSTMENTS
3. LOWER VOLTAGE LEVEL ADJUSTMENT FOR EXTERNAL DC SOURCE . If external DC supply
lV. This instrument stops functioning. That lower voltage level is adjustable with VR2.
voltage drops lower than I
4. ADJUSTMENTS ABOUT CRT . . . Aged CRT has tendency to lose brightness of trace line and distortion of
waveforrn display increases.
To compensate the detrition, readjustment may be required. In this case proceed as follows;
a. 'When FLY-BACK LINE appears on the CRT with waveforms . . . Adjust VRl0 to obtain the right tuning
point of the lower blanking pulse level. And this to be done, observing the waveform between Emitter of Ql4 and
the ground.
b. When Brightness decreased . . . Adjust VRI I ior intensity control.
@TooMUCHBRIGHTNESSSHoRTENSTI{ELIFEoFCRT.
,6 GEOMETRY
a\li,o
@vato
@vat
Qvn, @vat
a ",8u
Qvaz
FOIL SIDE VIEW
CALIBRATION LOCATIONS FOR POWER SUPPLY UNIT
-17-
SECTION 5 MAINTENANCE & ADJUSTMENTS
5-2-(2) VERTTCAL AMPLTFTER UNrT ADJUSTMENTS
1. ADJUSTMENTSOFATTENUATORS ....When the voltage readings are in error or waveform is distorted
a. Adjustments of voltage reading (VOLT/DIV)
Adjustments : VR5 for CH-A
VRl1 for CH-B
b. Adjusting Balance of attenuator steps . . . . . When trace line shifts with the change of VOLT/DIV switch.
Adjustments : VRI for CH-A
VR7 for CH-B
c. Adjustments of DC Balance (VARI BAL) When trace line moves up or down while tuning VARIABLE
knob.
Adjustments : VR3 for CH-A
VR9 for CH-B
2. ADJUSTMENTS OF VERTICAL AMPLIFIER
a. When trace lines shift with the change of DC-GND-AC slide switch.
Short the Test Pin and adjust VR6
Adjustment of Vertical POSITION's Linearity
Adjust VR4 for CH-A and VRl0 for CH-B.
When adequate dynamic range is not obtained in display.
Confirm +8.7V between Base of Ql I and ground.
J. ADJUSTMENT OF X-AXIS AMPLIFIER GAIN . . . After both channels are confirmed to be correct in normal opera-
tions, Set SWEEP TIME/DIV control to CH-B. If there is difference of sensitivity in Y-axis and X-axis, adjust VR12.
ADJUSTMENT OF ATTENUATOR CAPACITY
a. CH-A TCI l/10 ATT Square waveform ADJ
TC2 1/10 ATT Input Cap. ADJ
TC3 l/100 ATT Square waveform ADJ
TC4 1/100 ATT Input Cap. ADJ
TC5 1/1000 ATT Square waveform ADJ
TC6 1/1000 ATT InputCap.ADJ
b. CH-B TC7 l/10 ATT Square waveform ADJ
TCS l/10 ATT Input Cap. ADJ
TC9 1/100 ATT Square waveform ADJ
TC10 l/100 ATT Input Cap. ADJ
TC I I I / I 000 ATT Squ are wave form ADJ
TC12 l/1000 ATT Input Cap. ADJ
- 18 -
SECTION 5 NIAINTENANCE & ADJUSTMENTS
@van rcs@
@r^o Qtca
Qvaz
Qr^u rct@
ercz
@vaa rcsQ Qrca
@vat
@vato
rut@
Qvar Qtuz
Qvas
rctQ
Qrce
Qvatz Qvat rcs@
Otuo
FOIL SIDE VIEW
CALIBRATION LOCATIONS FOR VERTICAL AMPLIFIER UNIT
-19_
SECTION 5 MAINTENANCE & ADJUSTMENTS
5-2.(3) HORIZONTAL/TIME BASE UNIT ADJUSTMENTS
L ADJUSTMENT OF SWEEP TIME/DIV (A standard time marker generator required.)
a. Adjust VR6 for realignment of the range from 0.1msec/DIV to 0.5 sec/DIV.
b. Adjust TCI for realignment of the range from I gseciDIV to 50 psec/DIV.
c. Adjust TC2 for realignment of the range from 0.5 gsec/DIV to 50 gsec/DIV.
ADJUSTMENT OF 5X MAGNIFIER
a. When magnification is inaccurate.
Adjust VR9.
b. Shift ol center position of screen. Adjust VR7 to obtain the same center when the display is magnified.
-) OTHERS BESIDES TIME BASE CIRCUIT
a. Adjustment of Horizontal POSITION . . . . When shift range is unbalanced to left and right. Adjust VR10
to obtain the same shift ranges.
b. Adjustment of Sweep Linearity .....AdjustVRll.
4 ADJUSTMENTOFTRIGGERING .. . When the starting point shifts with the change of SYNC switch (+ to , or vice
versa). Adjust VR3.
5. ADJUSTMENT OF X-AXIS (CH-B) POSITION . With SWEEP TIME/DIV control set at CH-B, check
if shilt range is balanced when X-axis POSITION (CH-B VERTICAL POSITION) is turned. If there is unbalance, Adjust
VR8.
6. ADJUSTMENT OF TRACE LINE LENGTH Adjust VR5 to obtain the length of I IDIV on CRT screen
VRgVRlOVR-I 1
FOIL SIDE VIEW
CAL!BRAT]ON LOCATIONS FOR HORIZONTAL/TIME BASE UNIT
-20
SECTION 6 PARTS LIST
PARTS LIST
5.I CHASSIS
REF. NO. PARTS NO. DESCRIPTION
lOO-10O542 Case
110-1m2-O2 Diecast Panel
u8-roo5{3 Ornamental Panel
125-1mO{3 Rear Panel
z3o-roooo4 Battery Case
140-100043 Frame (A)
r40-100143 " (g)
140-roo243 " (c)
I 140-1003{3 " (D)
140-100443 " (E)
330-rOOO43 CRT Shield Case
I 330-1O1O{3 CRT Shie1d Cover
330-100244 Shield Plate
255-rOO3{3 CRT Band
4oo-1ooo{3 Carrying Handle
4e3-roooo4 Handle Mounting Bracket(1)
4o3-toor{4 (2)
3r5-rooo-o4 Spring
3O5-rOOl{3 Handle Cap
2oo-1ooo{3 "CAL" Terrninal
2oo-rool{4 Grounding Terminal
25o-tOOO-O4 Joint Metal
245-1mO-O4 Bakelite Bar (e)
245-1OO1{4 " (B)
160-100243 Rotation Coil Bracket
235-1OOO44 Molded Bearing
415-1m143 BezeL
125-1mO44 Graticule
LED for Power SG241B
LED for
charge *247
215-1mO{5 CRT Socket
205-1mo{5 Power Crcnnector
2O5-1OO145 Connector for EXT If
2ro-1mo45 Connector Plug for EXT m
260-100045 BNC Receptacle
275-1OOO-O5 Grounding Lug for BNC Receptacle
2go-rooo{5 P.C.B. for LED
270-1OOO45 Assembled,,Connector' JF-AC Connector
270-Lon,z45 SPJP
270-1003{5 7P4P
270-1m445 I
{PJ)C Connector
270-1005{5 I
5P-LED
27c,-rcr],645 n
3F4RT
27C,-Lco745 tl
:IP{RT
270-1m845 TI
JF-Position(CU-e)
270-100945 il
" (cu-n)
270-roro{5 I
" (uon)
zrc-rcn2-o5 II
]P44L Terrninal
I
270-1013-O5 3,P-EXT TRIG
I
Z7o-LOL445 9P4RT
r
27C,-LOL645 JP-Battery
I
270-LOL745 9P-9P
lt
270-1018{5 4P+ULL INVERT SI{
tt
270-101945 4PJ{AG SI{
- 21-
SECTION 6 PARTS LIST
REF. NO. PARTS NO. DESCRIPTION
298-1ooo45 Power Line cord ror
298-100145
298-roo2{5 ft{T}':'*
SAA type
298-1OO3{5 " JIS type
080-100045 Fuse O.3A
o8o-10o1{5 "ZA
Cathode Ray Tube 95G831
42o-looo-o4 Knob for Rotary Switch
42O-rOOr{4 Knob for Potentiometer
l8o-Lol24l+ Ihob for Rotary Switch
42o-roo3-o4 Knob for Lever Switch
405-1000-o4 Rubber Leg
340-1000{4 Felt (A)
340-rool-o4 " (g)
435_1oo244 s/No. Plate
435-1oo3-o4 Plate for,,Power Source gov - 13ov
435-1oo444 180v - 260v
435-1006{4 Name Plate for ASTfG
435-1oo7{4 '' CH-A BAL
435-1oo8{4 "
,'
CH-A STEP BAL
435-1oo9{4 CH-B BAL
435-101044 ,' CH-B STEP BAL
37O-lOOO{3 Packing Case
38O-lOOO-O3 Packing Material
375-1oOO{4 Polyethylene Bag
040-1000{5 Power Transformer
o5o-1ooo-o5 Rotation Coil
Ferri-Inductor FLI+II2PZK(Z.zvE)
m2-rooo{5 Variable Resistor ttsa-B (V. eosition CH-A )
oo2-1007-o5 lISe-B( " W/PULL SH)
oo2-loor{5 2ol(se-B(H.Position)
Carbon Resistor 33c[? L/8u t5%
2?R 1/8w !5y,
Metal Filmed Capacitor o.o22pF 63OV !2A'/"
026-looo{5 Power Switch
o2o-rooo{5 Slide Switch for AC4ND-E Non-Shorting.
o2o-roor{5 Slide Switch for Battery
Operation
og5-looo-o5 Ni4d Battery NP-SCU lzOOnAH
*
rB
-22-
SECTION 6 PARTS LIST
6.2 VERTICAL AMPLIFIER I,'NIT
REF. NO. PARTS NO. DESCRIPTION
PL121517 Connector 5048-3{
P3
Pl+ I
I
fi48:te
5048-%
P6 I
5048-4^
2W-1Ctr,2-I11 Printed Circuit Board
L1-4 Ferri-Inductor OpH
L5-6 I
o.58pH
L74 47otiH
IClJ Linear Integrated Circuit HAILZ7 orCA3O45
IC-3 Digital Integrated Circuit CD4OOf or IilCl4OOlB
IC_4 lr
CD4O11B or I|CI4O11B
IC-5 il
sN74[SO3N
Qlr25 F.E. T. 2sK3oA(o)
Q2,26 DraI F.E.T. 2SK5E-1-lril
Q3-6,9-1o,27-3o Transistor 2rc535(c)
Q74 ,12-ll+,21-22 ,31-32 ,36 It
2sA836
QLl, t5-7 6, 23-2 4, 33-35 il
2sC{!8D or E
Q17-IB