TTI QL II Series User manual

QL Series II
Precision Power
Supplies
Service Manual
Book Part Number 48511-1740 - Issue 1

1
Table of Contents
Specification 2
Safety 5
General 6
Circuit Descriptions 7
Calibration 10
Parts List 12
Interconnection Diagram 32
Component Layouts 33
Circuit Diagrams 39

2
Specification
General specifications apply for the temperature range 5°C to 40°C. Accuracy specifications apply
for the temperature range 18°C to 28°C after 1 hour warm-up with no load and calibration at 23°C.
Typical specifications are determined by design and are not guaranteed.
MAIN OUTPUTS
Voltage/Current Ranges:
QL355
QL564
0V to 35V/0·001A to 3A
0V to 35V/0·1mA to 500mA
0V to 15V/0·001A to 5A
0V to 56V/0·001A to 2A
0V to 56V/0·1mA to 500mA
0V to 25V/0·001A to 4A
Voltage Setting: Resolution 1mV
Accuracy ± (0·03% + 5mV)
Current Setting: Resolution 1mA; 0·1mA on 500mA range
Accuracy ± (0·2% + 5mA); ± (0·2% + 0·5mA) on 500mA range.
Output Mode: Constant voltage or constant current with automatic cross-over.
CI indicator lit in constant current mode.
Output Switch: Electronic, non isolating. Switch illuminated when Output on.
Preset voltage and current limit displayed when Output off.
Output Terminals: Universal 4mm safety binding posts on 19mm (0·75”) pitch for Output;
screwless terminals for Sense.
Duplicate rear panel Output and Sense screw terminals on P models.
Transient Response: <50µs to within 15mV of set level for a change in load current from full
load to half load or vice versa.
Voltage Programming
Speed:
Maximum time required for output to settle within 1% of its total
excursion (for resistive load). Excludes command processing time.
QL355
QL564
Full Load No
Load Full Load No
Load
Up
Up
Up
15V 5A
35V 3A
35V 500mA
6ms
20ms
200ms
6ms
7ms
40ms
25V/4A
56V/2A
56V/500mA
10ms
40ms
300ms
6ms
15ms
60ms
Down
Down
Down
15V 5A
35V 3A
35V 500mA
6ms
25ms
120ms
250ms
600ms
600ms
25V/4A
56V/2A
56V/500mA
10ms
50ms
200ms
400ms
800ms
800ms
Ripple and Noise
(20MHz bandwidth):
Normal mode voltage: <0·35mVrms and 2mVp-p
Normal mode current: <0·2mArms; <20µArms on 500mA range.
Load Regulation: For any load change, measured at the output terminals, using
remote sense.
Voltage <0·01% + 2mV.
Current <0·01% + 250µA; <0.01% +50µA on 500mA range.
Add typically 2·5mV for a 0·5V drop in the positive output lead.
Specification applies for sense lead resistance <0·5Ω.
Line Regulation: Voltage <0·01% + 2mV for 10% line change.
Current <0·01% + 250µA; <0.01%+ 50µA on 500mA range.
Temperature Coefficient: Voltage: typically <(50ppm + 0·5mV)/°C
Current: typically <(100ppm + 1mA)/°C;
typically<(100ppm + 0·1mA)/°C on 500mA range.
Output Protection: Output will withstand forward voltages of up to 20V above rated output
voltage. Reverse protection by diode clamp for currents up to 3A.

3
Over-voltage Protection:
(OVP) Range 1V to 40V (QL355), 1V to 60V (QL564) Resolution 0·1V; accuracy ± (2% + 0·5V)
Response time typically 100µs
Over-current Protection:
(OCP) Range 0·01A to 5·5A (QL355), 0·01A to 4·4A (QL564) Resolution 0·01A; accuracy ± (0·2% + 0·01A)
Response time typically 35ms
Protection Functions:
Output trips off for OVP, OCP, over-temperature and Sense miswiring
METER SPECIFICATIONS (Main Outputs)
Display Type:
5-digit (Volts), 4-digit (Amps), 14mm (0·56") LED.
Voltage (CI mode): Resolution 10mV
Accuracy ± (0·1% of reading + 10mV)
Current (CV mode): Resolution 0·001A; 0·1mA on 500mA range
Accuracy ± (0·2% + 0·005A); ± (0·2% + 0·5mA) on 500mA range
V x A: Resolution 0·01W; 0·001W on 500mA range
Accuracy ± (0·3% + 0·05W); ± (0·3% + 0·005W) on 500mA range
AUXILIARY OUTPUT (T models only)
Voltage Range:
1V to 6V
Voltage Setting: Resolution: 10mV
Accuracy: ± 0.5% ±10mV
Current Limit:
3A minimum
Output Switch:
Electronic, non isolating. Switch illuminated when Output on.
Output Terminals: Universal 4mm safety binding posts on 19mm (0·75”) pitch. Duplicate
screwless terminals on rear panel.
Output Protection: Output will withstand up to 16V forward voltage. Diode clamp reverse
protection for currents up to 1A. Over-current trip.
Ripple & Noise:
(20MHz bandwidth)
<2mV rms, 10mVp-p
Load & Line Regulation:
<1·0% for a 90% load change; 0·1% for a 10% line change.
Status Indication: Current limit lamp. Current overload trip indication.
Meter Specifications:
(use SET/VIEW button) Voltage Meter: Resolution 10mV, accuracy ± 0.5% ±10mV Current Meter: Resolution 10mA, accuracy ± 0.5% ±10mA
Voltage Programming
Speed:
Maximum time required for output to settle within 1% of its total
excursion (for resistive load). Excludes command processing time.
1V to 6V: 10ms, no load and full load
6V to 1V: 10ms, no load and full load
KEYBOARD & ROTARY CONTROL
All functions, including the selection and set-up of the remote control interfaces, can be set from
the keyboard. The rotary jog control can be used to adjust output voltage and current settings in a
quasi-analogue mode.
ALARM OUTPUT
Isolated rear-panel open-collector output signal. User can select output to be activated for either
OVP, OCP, Overtemperature or Sense miswiring, or for any of those four faults.

4
DIGITAL INTERFACES (P models only)
Full digital remote control facilities are available through the RS232, USB, LAN and GPIB interfaces.
General
RS232:
Standard 9-pin D-connector. Variable Baud rate (600 to 19200).
GPIB:
Conforming with IEEE488.1 and IEEE488.2
USB:
Standard USB 2.0 hardware connection. Operates as a virtual COM port.
LAN: Ethernet 100/10base-T hardware connection. Auto speed detect, auto
MDIX. LXI V1.2, Class C compliant.
Remote Command
Processing Time: Typically <25ms between receiving the command terminator for a step voltage change at the instrument and the output voltage beginning to
change.
Status Indication:
Remote mode and LAN status indicators
Main Outputs
Voltage Setting:
16-bit; Resolution 1mV, accuracy ± (0·03% +5mV)
Current Setting: 16-bit; Resolution 0.1mA, accuracy ± (0·2% + 5mA)
Resolution 0.01mA, Accuracy ± (0·2% + 0·5mA) on 500mA range.
Readback V & I
See meter specifications.
Auxiliary Output (T models only)
Voltage Setting:
Resolution 10mV, accuracy ± 0.5% ±10mV
Current Setting:
Resolution 10mA, accuracy ± 0.5% ±10mA
Readback V & I
See meter specifications
GENERAL
AC Input: 230V AC or 115V AC ± 10%, 50/60Hz
Installation Category II
Power Consumption:
Single output: 250VA max; Triple output: 500VA max.
Operating Range:
+5ºC to +40ºC, 20% to 80% RH
Storage Range:
−40ºC to + 70ºC
Environmental:
Indoor use at altitudes up to 2000m, Pollution Degree 2.
Cooling: Intelligent variable-speed fan. Over-temperature trip shuts down
output if internal temperatures exceed predetermined thresholds.
Store/Recall: Up to 50 set-ups each main output, 50 linked set-ups, and 10 auxiliary
output settings can be saved and recalled via the keyboard or remote
interfaces.
Safety:
Complies with EN61010−1
EMC:
Complies with EN61326
Size: Single output: 140 x 160 x 290mm (WxHxD), excl. feet & terminals.
Triple output: 280 x 160 x 290mm (WxHxD), excl. feet & terminals
Weight: Single: 5.5kg; Triple: 10·5kg

5
Safety
This power supply is a Safety Class I instrument according to IEC classification and has been designed to
meet the requirements of EN61010-1 (Safety Requirements for Electrical Equipment for Measurement,
Control and Laboratory Use). It is an Installation Category II instrument intended for operation from a
normal single phase supply.
This instrument has been tested in accordance with EN61010-1 and has been supplied in a safe
condition. This instruction manual contains some information and warnings which have to be
followed by the user to ensure safe operation and to retain the instrument in a safe condition.
This instrument has been designed for indoor use in a Pollution Degree 2 environment in the
temperature range 5°C to 40°C, 20% - 80% RH (non-condensing). It may occasionally be
subjected to temperatures between +5°C and –10°C without degradation of its safety. Do not
operate while condensation is present.
Use of this instrument in a manner not specified by these instructions may impair the safety
protection provided. Do not operate the instrument outside its rated supply voltages or
environmental range. WARNING! THIS INSTRUMENT MUST BE EARTHED
Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited. The protective action must not be
negated by the use of an extension cord without a protective conductor.
When the instrument is connected to its supply, terminals may be live and opening the covers or
removal of parts (except those to which access can be gained by hand) is likely to expose live
parts. The apparatus shall be disconnected from all voltage sources before it is opened for any
adjustment, replacement, maintenance or repair.
Capacitors inside the power supply may still be charged even if the power supply has been
disconnected from all voltage sources but will be safely discharged about 10 minutes after
switching off power.
Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided
as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of
the hazard involved.
If the instrument is clearly defective, has been subject to mechanical damage, excessive moisture
or chemical corrosion the safety protection may be impaired and the apparatus should be
withdrawn from use and returned for checking and repair.
Make sure that only fuses with the required rated current and of the specified type are used for
replacement. The use of makeshift fuses and the short-circuiting of fuse holders is prohibited.
Do not wet the instrument when cleaning it.
The following symbols are used on the instrument and in this manual:-
Earth (ground) terminal.
mains supply OFF.
l
mains supply ON.
alternating current (ac)
direct current (dc)

6
General
Service Handling Precautions
Service work or calibration should only be carried out by skilled engineers using high quality test
equipment. If the user is in any doubt as to his competence to carry out the work, the instrument
should be returned to the manufacturer or their agent overseas for the work to be carried out.
Please note the following points before commencing work.
The tracks on the printed circuit boards are very fine and may lift if subjected to excessive heat.
Most of the integrated circuits are static sensitive and great care should be taken when handling
them to avoid damage due to static discharge. Also, most devices on the Control board are
surface mounted components with very fine leads on small pitches. These components must be
removed and replaced with great care to avoid damage to the PCB. It is essential that only the
proper tools and soldering equipment as recommended for surface mount components are used.
Dismantling the instrument WARNING!
Disconnect the instrument from all voltage sources before it is opened for adjustment or repair. If
any adjustment or repair of the opened instrument is inevitable it shall be carried out only by a
skilled person who is aware of the hazards involved.
1. Remove the six screws retaining the top cover and lift clear.
2. To remove the pcbs, first improve access by unscrewing the front panel: remove the screw(s)
securing the front panel bracket(s) to the spacer in the centre of the Power pcb(s) and remove the
screws that fix the bottom edge of the front panel to the chassis. The front panel can be tipped
forward to give access to the latching connectors connecting the Keyboard to the Power pcb;
disconnect these, noting orientation.
3. To remove the Power and Control pcbs remove the two screws securing the Power pcb to the
central fan bracket and the two screws fixing the Power pcb bracket to the rear panel. Unplug the
two transformer connectors, the fan connector and any inter-pcb connections (Power to Power on
a triple output supply, and/or Power to Interface on programmable versions) noting their positions
carefully; a diagram is provided at the end of this manual showing how these connections are
made. The Control pcb is plugged into the Power pcb and both can now be lifted clear together.
4. The Display/Keyboard pcb can be removed from the front moulding after pulling off the jog wheel
and removing the fixing screws, two of which also secure the front panel bracket (four on the
triple).
5. To remove the Interface pcb from the rear panel, undo the jackscrews of the GPIB and RS232
sockets and the self-tap screw in the chassis which retains the inner support bracket.
6. When re-assembling the instrument ensure that all fixings use the correct fasteners. Replace cut
cable ties. Do not over tighten the display/keyboard fixing screws in the moulding. Check that the
fan operates.

7
Circuit Descriptions
The Power board contains the main power supply and the auxiliary supplies used internally, the
output series regulator transistors, the microcontroller, display drivers and some control logic.
The Control board contains voltage and current control, ADC and DAC and some control logic.
The linear regulator is in series with the positive output but, because of the way in which the
control circuit is referenced to the +ve output, it is convenient to consider the regulated output as
the negative side.
To help reading the circuit diagrams the two connectors between the power and control pcbs join
as follows. PJ14 to PJ18 and PJ20 to PJ19.
Power Pcb
The main windings are connected either in series (for the high voltage range) or in parallel (for the
low voltage range) by the range relays and an electronic tap change at approximately half range is
used to reduce dissipation. Bridge rectifier BR1 feeds C4 the reservoir capacitor when tap change
is low. When tap change is high, two of the diodes in BR1 are bypassed by SCR1 and SCR2.
Voltages are listed below at nominal mains (230V).
QL355
35V/3A 15V/5A
Secondary – high tap, no-load
39.8VAC
19.9VAC
Secondary – high tap, full-load
37VAC
18.9VAC
C4 – high tap, no-load
51.5VDC
24.5VDC
C4 – high tap, full-load
44.7VDC
21.9VDC
QL564
56V/2A 25V/4A
Secondary – high tap, no-load
60VAC
30.1VAC
Secondary – high tap, full-load
56VAC
28.6VAC
C4 – high tap, no-load
79.5VDC
38.4VDC
C4 – high tap, full-load
69.5VDC
35.2VDC
A 30Vrms centre tapped winding and full wave rectification provide the auxiliary supplies. IC1
generates +10V and IC2 –5V. A 10.4Vrms winding and full wave rectification power the relays and
fan and IC3 provides the +5V for the microcontroller, display and control logic.
Comparator IC6A provides the system reset signal and comparator IC6B provides the power fail
signal to the microcontroller to store the instrument settings at power down.
The fan speed is regulated by a pulse width modulator in the microcontroller; if the heatsink
exceeds a certain temperature measured by Q22, comparator IC50A switches the fan to full
speed. If the heatsink temperature continues to rise IC50B will pull the over-temperature line low
which will turn the output off.
Q15 and Q16 are the series regulator transistors; long-tailed pair Q17 and Q21 ensure current
sharing. The +10V supply to emitter follower Q14 is via switch Q13 which is turned on after a delay
to prevent output glitches when power is turned on.
Microcontroller IC9, which is factory programmed, writes the calibration values and instrument
settings to non-volatile memory IC31, reads the keyboard, spin-wheel and status of the instrument
via shift registers (4021s), reads the ADC, outputs data via shift registers (4094s) and display
drivers IC32, IC33 and IC38, and writes to the DAC.

8
Jumpers are fitted to SEL1 to 7 to inform the microcontroller of the model type and to LK1 and LK2
to power the opto-couplers, see table below.
SEL1
SEL2
SEL3
SEL4
SEL5
SEL6
SEL7
LK1
LK2
QL355
Yes
QL355P
Yes
QL355T
output 1
Yes Yes
QL355T
output 2
Yes
QL355TP
output 1
QL355TP
output 2
Yes
QL564
Yes
QL564P
Yes
QL564T
output 1
Yes Yes Yes
QL564T
output 2
Yes Yes
QL564TP
output 1
Yes
QL564TP
output 2
Yes Yes
The transformer windings are in series for the high voltage range and in parallel for the low voltage
range. D4, R14,C16 and D7,R15,C17 ensure the correct switching sequence of the range relays.
IC8C and IC8D form an oscillator to drive the buzzer.
TP2 carries a synchronising pulse output which makes it possible to view the DAC sample and
hold outputs and the ADC input selector signals.
TP3 provides an output that toggles at each stage of the range change switching sequence.
Control Pcb
IC2 is a 16-bit DAC and the reference to it is supplied via IC19B which allows fine adjustment for
voltage and current settings. The DAC output is multiplexed into 7 sample and holds. IC14A is for
the voltage control (VC); when the output is off IC42B grounds its input via VR2. IC28B drives the
guard track (GV) round the VC sample and hold. An identical circuit is used for the current control
(IC). IC20B is the voltage control error amplifier and IC21A is a differential amplifier. With the
output at 35.0V VM will be -1.74V and VC will be 1.47V. Comparator IC26B is for over voltage
protection (OVP). A relay selects local or remote voltage sensing; if the voltage between an output
and its sense reaches 2xVbe either Q19 or Q20 will turn on turning the output off.
IC20A is the current control error amplifier and IC22 is a differential amplifier with a gain of 10. R50
is used for the high current range and R51 is used for the 500mA range selected by IC23. Q3
shorts out R51 when the high current range is selected. If the current limit is set to 2.0A IC will be
approximately 846mV. With a 2Amp load on the high range IM will be –1V. Over current protection
(OCP) is realised in software. When the power supply is in constant current mode IC20A has
control and comparator IC17B drives the CI line high.

9
IC37 is a 12-bit ADC; ADREF is adjusted for voltage and current measurements and is
approximately 4V. IC27B has a gain of –2; therefore if, for example, VM was –2V then the output
of IC27B would be +4V. Offsets are trimmed by ADOFST. To achieve 13-bit resolution two
measurements are taken with and without the 13th bit subtracted from the input selected by IC24C.
Any trip condition is latched by IC29 and IC30 and cleared by the microcontroller by pressing
escape. IC18 is used for synchronising the switching of the outputs on triple units.
Auxiliary Output
Each transformer has a 5Vrms winding and these are connected in series at the Auxiliary Power
pcb. Regulator IC5 provides 5V. IC1 is a step down switching regulator (buck). Microcontroller
IC11 sets the output voltage with a PWM signal via low pass filter IC4B. IC4D is the voltage error
amplifier and IC4A signals if the loop comes out of regulation. Using an internal ADC IC11
measures the output voltage and current. The opto-couplers provide isolated communication with
the processor on Output 1.
Interface Pcb
The interface board allows the unit to communicate externally via USB, RS232, LAN or GPIB. IC2
is an ARM7 processor which is programmed in-cicuit using the standard JTAG port accessed at
PJ5. IC3 is the Ethernet transceiver. IC1 is the RS232 transceiver it has a charge pump to
generate –5V. IC31, IC32 and IC33 form the GPIB interface. IC33 is a GPIB controller IC and
performs all the GPIB hardware handshaking and status reporting. IC31 and IC32 are GPIB
specific buffers.
Servicing Note
If IC31 the memory IC located on the power pcb is replaced it is very likely the check sums do not
match resulting in “error 999” being displayed. Pressing OK will get out of this condition and
initialise the EEPROM. This will only work on a single power supply or on output 2 on a triple power
supply. If IC31 has to be replaced on output 1 side of a triple power supply, output 1 and output 2
power boards will have to be interchanged, also links will have to be changed (see table under
Power Pcb desciption) so that the power supply can initialise.

10
Calibration
Refer to the General section for dismantling instructions and safety precautions. Normal calibration
is done without opening the instrument.
Allow 10 minute warm-up before commencing calibration.
Refer to the User Manual for detailed operation of these power supplies.
Equipment Required
A 5.5 digit multimeter with better than 0.02% accuracy on dc volts and better than 0.12% accuracy
on dc current (to 5A); alternatively use a precision shunt for current measurement. An electronic
load set to approximately 2.7A or a 1.8Ω15W resistor.
Calibration
To enter calibration press SHIFT, #, 99. If the instrument is a long way out of calibration or has
been repaired, the default calibration values should be loaded first by pressing SHIFT #, 91.
Pressing ESCAPE at anytime will abort the calibration procedure and revert to the stored
calibration values.
Having entered calibration mode, follow the table below. To increment to the next step press OK.
The calibration must be done in sequence. At the end of calibration press OK to store the
calibration. The instrument automatically sets the range and settings at each step.
Use the spin-wheel to adjust calibration; holding down the JOG SET OFF key will give x100
increments to speed up calibration. Pressing SHIFT will show the calibration value.
On triple units calibrate both output 1 and output 2.
There are two internal adjustments which are factory set and will normally only require adjustment
if a component has been changed in the associated area. If this is so proceed as follows. VR1 and
VR2 are both located near the top of the control pcb. They are accessible from both sides of the
board. Turn them both fully clockwise as viewed from the component side, fully anti-clockwise as
viewed from the solderside. Adjustment is done with the output set to off. Connect an ammeter
across the output terminals and adjust VR1 for +1mA. Remove ammeter and connect voltmeter
and adjust for VR2 –10mV. (minus or negative 10mV).
Calibration steps 17 to 22 on output 1 are for the Auxiliary output.
QL355
Step/Range
Settings
Adjust for:-
Load
Detail
1, 35V 3A
0.01V 3A
10mV ± 0.5mV
DVM
o/p 0V
2, 35V 3A
0.01V 3A
0.010V on display
DVM
V readback zero
3, 35V 3A
35V 3A
35V ± 0.5mV
DVM
o/p V span
4, 35V 3A
35V 3A
35.000 on display
DVM
V readback span
5, 35V 3A
0.01V 3A
10mV ± 0.5mV
DVM
o/p 0V
6, 35V 3A
35V 3A
35V ± 0.5mV
DVM
o/p V span
7, 35V 3A
2V 0.001A
1mA ± 0.5mA
milli-ammeter
o/p A offset
8, 35V 3A
2V 0.001A
0.001 on display
milli-ammeter
A readback zero
9, 35V 500mA
2V 0.1mA
0.1mA ± 0.05mA
milli-ammeter
o/p mA offset
10, 35V 500mA
2V 0.1mA
flashing 0.0/0.1 on display
milli-ammeter
mA readback zero
change load
11, 15V 5A
2V 4A
4A ± 0.5mA
ammeter
o/p A span
12, 15V 5A
2V 4A
4.000 on display
ammeter
A readback span
13, 15V 5A
2V 4.1A
4.100 on display
ammeter
A readback 13bit
Continued….

11
14, 35V 500mA
2V 400mA
400mA ± 0.05mA
ammeter
o/p mA span
15, 35V 500mA
2V 400mA
400.0 on display
ammeter
mA readback span
16, 35V 500mA
2V 410mA
410.0 on display
ammeter
mA readback 13bit
17, Aux o/p
5V
5.00V ± 10mV
DVM
o/p V span
18, Aux o/p
5V
5.00V on display
DVM
V readback
19, Aux o/p
1V
1.00V on display
DVM
V readback
20, Aux o/p
5V
5.00V ± 0.5mV
DVM
V readback
21, Aux o/p
off
0.000 flashing 0.001
A readback zero
22, Aux o/p 5V Display equals ammeter Electronic load
or 1.8Ωload in
series with
ammeter
A readback
QL564
Step/Range
Settings
Adjust for:-
Load
Detail
1, 56V 2A
0.01V 2A
10mV ± 0.5mV
DVM
o/p 0V
2, 56V 2A
0.01V 2A
0.010V on display
DVM
V readback zero
3, 56V 2A
35V 2A
35V ± 0.5mV
DVM
o/p V span
4, 56V 2A
35V 2A
35.000 on display
DVM
V readback span
5, 56V 2A
41V 2A
41.000 on display
DVM
V readback 13bit
6, 56V 2A
0.01V 2A
10mV ± 0.5mV
DVM
o/p 0V
7, 56V 2A
35V 2A
35V ± 0.5mV
DVM
o/p V span
8, 56V 2A
2V 0.001A
1mA ± 0.5mA
milli-ammeter
o/p A offset
9, 56V 2A
2V 0.001A
0.001 on display
milli-ammeter
A readback zero
10, 56V 500mA
2V 0.1mA
0.1mA ± 0.05mA
milli-ammeter
o/p mA offset
11, 56V 500mA
2V 0.1mA
flashing 0.0/0.1 on display
milli-ammeter
mA readback zero
change load
12, 25V 4A
2V 4A
4A ± 0.5mA
ammeter
o/p A span
13, 25V 4A
2V 4A
4.000 on display
ammeter
A readback span
14, 56V 500mA
2V 400mA
400mA ± 0.05mA
ammeter
o/p mA span
15, 56V 500mA
2V 400mA
400.0 on display
ammeter
mA readback span
16, 56V 500mA
2V 410mA
410.0 on display
ammeter
mA readback 13bit
17, Aux o/p
5V
5.00V ± 10mV
DVM
o/p V span
18, Aux o/p
5V
5.00V on display
DVM
V readback
19, Aux o/p
1V
1.00V on display
DVM
V readback
20, Aux o/p
5V
5.00V ± 0.5mV
DVM
V readback
21, Aux o/p
off
0.000 flashing 0.001
A readback zero
22, Aux o/p 5V Display equals ammeter Electronic load
or 1.8Ωload in
series with
ammeter
A readback

12
Parts List
PCB ASSEMBLY – POWER – QL355
Part No. Description Position
20073-
9801
SCREW No.4x1/4in. Plastite HEATSINKS
20613-
0026
SIL-PAD 900S 100MM X 25MM FOR HS1, HS2
20670-
0366
HEATSINK LS01000 100MM PLAIN SK1-2
20670-
0367
CLIP 1 FOR TO220/TO247 H/S FOR IC1-3,Q22,SCR1-
2,BR1,Q15,Q16
22240-
0150
RELAY 12V DPDT 8A RL1-2
22312-
0242
FUSE CLIPS PCB MTG FS1
22315-
0310
FUSE 10A ANTISURGE(T) HBC UL FS1
22315-
0451
FUSE 750mAT SUBMIN PCB MNT UL FS4 ,FS6
22315-
0452
FUSE 1.0AT SUBMIN PCB MTG UL FS5
22573-
0041
HEADER 2WAY STR SIL STD/GOLD LK1-3, TP1, TP5, TP2-
4 (1 PIN EACH)
22573-
0071
HEADER 5 WAY STR SIL STD PJ8
22573-
0150
HEADER 20 WAY STR LATCHING PJ10-11
22573-
0225
HEADER 5 WAY STR F/LOCK .156 PJ1
22573-
0226
HEADER 6 WAY STR F/LOCK .156 PJ2
22573-
0247
HEADER 2 WAY STR .1P F/LOCK PJ6 (Rear Mount), PJ7 (REAR MOUNTED),
PJ9
22573-
0251
HEADER 6 WAY STR .1P F/LOCK PJ5/PJ13 (R/MOUNTED)
22573-
0262
HEADER 2 WAY RT ANG F/LOCK .1P PJ4
22573-
0410
HEADER 10W (2x5) BOXED
PJ15 (REVERSE MOUNTED)
22575-
0038
HEADER 6 WAY STR SIL STD PJ3
22575-
0068
HEADER 14 WAY (2X7) STR SKEL PJ12
22575-
0103
HEADER 16 WAY (2X8) STR SKEL PJ14 ,PJ20
23202-
3100
RES 10K0F W60 MF 50PPM R3 ,R96
23274-
0104
RES 0R22J 3W WW R26-27
23424-
0443
CAP 10NZ 1KV CER D10 P5 C12-13
23557-
0660
CAP 2200U 16V ELEC RE2 P5 C3
23557-
0664
CAP 1000U 35V ELEC RE2 P5 C1-2
23557-
0770
CAP 10000U 63V ELEC LP5 P10 C4-5
23620-
0247
CAP 220NK 63V P/E P5 C16-17
23620-
0257
CAP 2U2K 100V P/E P22.5 C9-10
23620-
0263
CAP 220NK250VP/E 368 SER P15 C11 ,C23
23620-
9007
CAP 10NK 100V P/E P5 C87
25115-
0907
DIO 1N4002 B/R D20-22
25210-
0060
THYRISTOR 2N6507 TO-220 SCR1-2
25211-
0303
RECTIFIER BRIDGE 8A 200V SIL BR1

13
PCB ASSEMBLY – POWER – QL355 continued/…
Part No. Description Position
25211-
9302
RECTIFIER BRIDGE W02G BR2-3
25386-
9300
TRAN NPN TIP31A Q22
25601-
0590
TRAN MOSFET NCHAN HUF75639G3 Q15-16
27001-
0020
OPTO-COUPLER CNY17-3 0.3 UL IC44 ,IC52
27001-
0050
OPTO-COUPLER 6N136 IC48-49
27001-
0110
OPTO-COUPLED TRIAC 3011 IC4-5
27160-
0009
IC V/REG 7805 TO220 IC3
27160-0014 IC V/REG 7905 TO220 IC2
27160-
0200
IC V/REG LM317 TO220 IC1
28151-
0010
BUZZER - 41.T70P015H BUZZ1
28500-
1190
XTAL 18.432MHZ MICROPROCSR XTL1
44117-
0181
PCB ASSY SM POWER nQL355 S
PCB ASSEMBLY – SM POWER – QL355 and QL564
Part No. Description Position
23105-
0100
RES SM0805 10R0F W1 R93
23105-
0330
RES SM0805 33R0F W1 R133
23105-
0560
RES SM0805 56R0F W1 R124-125, R128, R131 ,R138-139 ,R145-
154
23105-
1100
RES SM0805 100RF W1 R12 ,R23-24
23105-
1180
RES SM0805 180RF W1 R1-2
23105-
1220
RES SM0805 220RF W1 R28
23105-
1270
RES SM0805 270RF W1 R110, R127 ,R142
23105-
1330
RES SM0805 330RF W1 R144
23105-
1360
RES SM0805 360RF W1 R60 ,R134
23105-
1390
RES SM0805 390RF W1 R40-41
23105-
2100
RES SM0805 1K00F W1 R4, R19, R111 ,R117, R122-
123 ,R130,
23105-
2120
RES SM0805 1K20F W1 R20
23105-
2150
RES SM0805 1K50F W1 R29
23105-
2220
RES SM0805 2K20F W1 R109
23105-
2470
RES SM0805 4K70F W1 R16-18, R112 ,R121
23105-
2510
RES SM0805 5K10F W1 R21-22 ,R132
23105-
2560
RES SM0805 5K60F W1 R52
23105-
3100
RES SM0805 10K0F W1 R5 ,R7-9, R13, R30, R120, R126 ,R136-
137,
23105-
3200
RES SM0805 20K0F W1 R6 ,R98-99
23105-
3220
RES SM0805 22K0F W1 R32-39, R116 ,R155-172
23105-
3330
RES SM0805 33K0F W1 R25, R75, R92, R129 ,R140
23105-
4100
RES SM0805 100KF W1 R11 ,R43

14
PCB ASSEMBLY – SM POWER – QL355 and QL564 continued/…
Part No. Description Position
23105-
4220
RES SM0805 220KF W1 R14-15 ,R143
23105-
5100
RES SM0805 1M00F W1 R10, R31, R115 ,R135
23407-
0100
CAP SM0805 10PG CER NPO C56-57
23407-
0101
CAP SM0805 100PG CER NPO C21-22
23461-
0020
CAP SM0805 100NZ 50V CER Y5V C15 ,C18-
20, C55, C58, C59, C61, C64
23461-
0040
CAP SM0805 1N0K 50V CER X7R C30-37 ,C47-54
23559-
3471
CAP SM 470U 16V AL ELEC C71
23559-
5100
CAP SM 10U 35V AL ELEC C6-8 ,C43
23559-
5220
CAP SM 22U 35V AL ELEC C14
23559-
6010
CAP SM 1U 50V AL ELEC C86 ,C88-90
25021-
1010
DIO SM BAS21 200V/200mA SOT23 D1-7 ,D24
25340-
1000
TRAN SM PNP BC859C SOT23 Q5-9 ,Q26
25340-
1010
TRAN SM PNP PMBT3906 Q13-14
25377-
1000
TRAN SM NPN BC849C SOT23 Q1-2 ,Q10-12, Q18 ,Q24
25381-
1000
TRAN SM NPN SMBT3904 Q17 ,Q21
25381-
1010
TRAN SM NPN BC817 Q23
27103-
1040
IC SM LM393 IC6 ,IC50
27164-
1070
IC SM ULN2003AD SOIC16 IC38
27227-
0210
IC SM 4021 IC34-35 ,IC41
27227-
0940
IC SM 4094 SO16 IC28
27239-
0000
IC SM 74HC00 SO14 IC8
27239-
0140
IC SM 74HC14 SO14 IC7
27239-
5740
IC SM 74HC574 SO20 IC32-33
27250-
2290
IC SM PIC16F887-I/PT 44TQFP IC9
27403-
0130
IC SM 24LC16B/SN SOIC8 IC31
35555-
5130
PCB - POWER - nQL355/564
PCB ASSEMBLY – POWER – QL564
Part No. Description Position
20073-9801
SCREW No.4x1/4in. Plastite
HEATSINKS
20613-0026
SIL-PAD 900S 100MM X 25MM
FOR HS1, HS2
20670-0366
HEATSINK LS01000 100MM PLAIN
SK1-2
20670-0367
CLIP 1 FOR TO220/TO247 H/S
FOR IC1-3,Q22,SCR1-2,BR1,Q15,Q16
22240-0150
RELAY 12V DPDT 8A
RL1-2
22312-0242
FUSE CLIPS PCB MTG
FS1
22315-0310
FUSE 10A ANTISURGE(T) HBC UL
FS1
22315-
0451
FUSE 750mAT SUBMIN PCB MNT UL FS4 ,FS6

15
PCB ASSEMBLY – POWER – QL564 continued/…
Part No. Description Position
22315-0452
FUSE 1.0AT SUBMIN PCB MTG UL
FS5
22573-0041
HEADER 2WAY STR SIL STD/GOLD
LK1-3, TP1, TP5, TP2-4 (1 PIN EACH)
22573-0071
HEADER 5 WAY STR SIL STD
PJ8
22573-0150
HEADER 20 WAY STR LATCHING
PJ10-11
22573-0225
HEADER 5 WAY STR F/LOCK .156
PJ1
22573-0226
HEADER 6 WAY STR F/LOCK .156
PJ2
22573-
0247
HEADER 2 WAY STR .1P F/LOCK PJ6 (rear mounted), PJ7 (REAR MOUNTED),
PJ9
22573-0251
HEADER 6 WAY STR .1P F/LOCK
PJ5/PJ13 (R/MOUNTED)
22573-0262
HEADER 2 WAY RT ANG F/LOCK .1P
PJ4
22573-0410
HEADER 10W (2x5) BOXED
PJ15 (REVERSE MOUNTED)
22575-0038
HEADER 6 WAY STR SIL STD
PJ3
22575-0068
HEADER 14 WAY (2X7) STR SKEL
PJ12
22575-0103
HEADER 16 WAY (2X8) STR SKEL
PJ14 ,PJ20
23202-3220
RES 22K0F W60 MF 50PPM
R3,R96
23274-0105
RES 0R33J 3W WW
R26,R27
23424-0443
CAP 10NZ 1KV CER D10 P5
C12-13
23557-0660
CAP 2200U 16V ELEC RE2 P5
C3
23557-0664
CAP 1000U 35V ELEC RE2 P5
C1-2
23557-0775
CAP 4700U 100V ELEC LP5 P10
C4,C5
23620-0247
CAP 220NK 63V P/E P5
C16-17
23620-0257
CAP 2U2K 100V P/E P22.5
C9-10
23620-0263
CAP 220NK250VP/E 368 SER P15
C11 ,C23
23620-9007
CAP 10NK 100V P/E P5
C87
25115-0907
DIO 1N4002 B/R
D20-22
25210-0060
THYRISTOR 2N6507 TO-220
SCR1-2
25211-0303
RECTIFIER BRIDGE 8A 200V SIL
BR1
25211-9302
RECTIFIER BRIDGE W02G
BR2-3
25386-9300
TRAN NPN TIP31A
Q22
25601-0790
TRAN MOSFET N FQA70N10 TO-3P
Q15,Q16
27001-0020
OPTO-COUPLER CNY17-3 0.3 UL
IC44 ,IC52
27001-0050
OPTO-COUPLER 6N136
IC48-49
27001-0110
OPTO-COUPLED TRIAC 3011
IC4-5
27160-0009
IC V/REG 7805 TO220
IC3
27160-0014
IC V/REG 7905 TO220
IC2
27160-0200
IC V/REG LM317 TO220
IC1
28151-
0010
BUZZER - 41.T70P015H BUZZ1

16
PCB ASSEMBLY – POWER – QL564 continued/…
Part No. Description Position
28500-1190
XTAL 18.432MHZ MICROPROCSR
XTL1
44117-0181
PCB ASSY SM POWER nQL355
PCB ASSEMBLY – CONTROL
Part No. Description Position
10300-0313 PAD P/E S/AD 12 X 15MM FOR R50
22240-0070 RELAY TYPE 47 (12VDC) RL3
22455-0040 TAB 4.8MAX 0.8MM STR PCB MTG FAS1, 2
22573-0251 HEADER 6 WAY STR .1P F/LOCK PJ3
22574-0316 SKT 16 WAY (2x8) PJ18,19
23105-1100 RES SM0805 100RF W1 R109
23105-1330 RES SM0805 330RF W1 R44-49,122
23105-2100 RES SM0805 1K00F W1 R38, 56, 78-81, 95,106,107,114
23105-2470 RES SM0805 4K70F W1 R28,91
23105-3100 RES SM0805 10K0F W1 R29,31,32,43,52,53,72,73,118,123,124,128
23105-3200 RES SM0805 20K0F W1 R67, 68,102,105
23105-3205 RES SM0805 20K5F W1 R35
23105-3470 RES SM0805 47K0F W1 R76
23105-4100 RES SM0805 100KF W1 R97, 98,108
23105-4220 RES SM0805 220KF W1 R77,103,104,113,131
23105-4270 RES SM0805 270KF W1 R66, 69
23105-4330 RES SM0805 330KF W1 R55, 62, 94
23106-2200 RES SM0805 2K00D W1 25PPM R83, 84
23106-3100 RES SM0805 10K0D W1 25PPM R99,100,120,121
23106-3110 RES SM0805 11K0D W1 25PPM R87
23106-3130 RES SM0805 13K0D W1 25PPM R88
23106-3200 RES SM0805 20K0D W1 25PPM R39, 82, 85,101
23202-1150 RES 150RF W60 MF 50PPM R54,125
23215-2845 RES 8K45B W25 MF 15PPM R63, 74
23215-3110 RES 11K0B W25 MF 15PPM R57
23215-3130 RES 13K0B W25 MF 15PPM R61
23215-4150 RES 150KB W25 MF 15PPM R64, 65
23284-0110 RES 0R51J 2W5 WW R51
23286-0040 RES 0R05J 15W WW ALUM HSD R50
23385-2220 RES PS/H 2K2 CF 6MM VR1, 2
23427-0388 CAP 220PK 100V CER P2.5 C81
23427-0388 CAP 220PK 100V CER P2.5 C49

17
PCB ASSEMBLY – CONTROL continued/…
Part No. Description Position
23427-9205 CAP 47PJ 100V CER NPO P2.5 C44-48, 62, 72, 74-78
23428-0100 CAP 10PG 100V CER NPO P2.5T C37
23557-0500 CAP 1U0 50V ELEC P1.5 C42
23557-0647 CAP 10U 35V ELEC P2 C24, 25, 27, 53, 58, 60
23557-0694 CAP 220U 100V ELEC P5 C40,41
23620-0246 CAP 100NK 63V P/E P5 C22, 23, 26, 28, 30, 33, 35, 36, 39, 54, 59,
65, 66, 79, 80, 82
23620-0247 CAP 220NK 63V P/E P5 C63
23620-0249 CAP 330NK 63V P/E P5 C31, 32, 34
23620-0252 CAP 2N2K 63V P/E P5 C50, 56, 61
23620-0286 CAP 470NF 100V P/E P5 C92, 93
23620-9007 CAP 10NK 100V P/E P5 C51, 52, 55, 57, 84
25021-0901 DIO 1N4148 B/R D9, 10, 15-19
25031-0040 DIO BAX16 D13, 14
25334-0011 TRAN PNP TIP30 Q18
25336-5590 TRAN PNP BC559C Q9
25341-0218 TRAN PNP 2N3906 Q25
25377-5490 TRAN NPN BC549C Q4, 5
25383-0610 TRAN NPN ZTX653 Q19, 20
25601-0620 TRAN MOSFET N CHAN LL Q3
27103-1040 IC SM LM393 IC17, 26
27106-0644 IC SM TL074CD BI-FET OP AMP IC15
27106-0645 IC SM TO072CD DUAL BIFET OP AMP IC31, 32
27106-1080 IC SM OP07CS IC22
27106-1240 IC SM MCP602 IC28
27106-1250 IC SM MCP602 OP AMP IC28
27153-1120 IC SM MCP3201B 12 BIT ADC IC37
27161-0061 IC V/REF AD680 T092 IC16
27162-1030 IC SM MAX5441 ACUA 16 BIT DAC IC1
27226-0510 IC 4051B 16 PIN IC13
27227-0210 IC SM 4021 IC36
27227-0510 IC SM 4051 IC25
27227-0750 IC SM 4075 IC18
27227-0940 IC SM 4094 IC11,IC43
27236-0530 IC SM 74HC4053 IC23-24, IC42, IC44
27239-1320 IC SM 74HC132 IC29-30
35555-3300 PCB - CONTROL

18
PCB ASSSEMBLY -INTERFACE
Part No. Description Position
20010-
0205
RIVET ALUM 2.4W X 6L PCB fixing(1)
20010-
0208
RIVET ALUM 2.4W X 8L FOR PJ10(2)
20040-
9501
NUT No.4 Angle PCB fixing
20210-
0112
NUT M3 BARB FOR IC15
20234-
0011
SCREW M3 X 10 PNHDPZ ZPST FOR IC15
20613-
0006
SIL-PAD TO220 LARGE HOLE FOR SK6
20670-
0066
HEATSINK -BMH/220/9007 SK6 (LAY FLAT)
22315-
0450
FUSE 500mAT SUBMIN PCB MNT UL FS1
22573-
0070
HEADER 4 WAY STR SIL STD TP1
22573-
0222
HEADER 2 WAY STR F/LOCK .156 PJ18
22573-
0248
HEADER 3 WAY STR .1P F/LOCK PJ3
22574-
0430
SKT 24W RA IEEE RC10-24R-LNA PJ10
22574-
0450
SKT 9W R/A D-TYPE (CLIP IN) PJ2
22574-
0495
SKT - USB TYPE B - PCB MTG PJ1
22574-
0900
SKT RJ45 - SI-60005-F PJ6
22575-
0065
HEADER 20 WAY 2X10 STR SKELN PJ5
23557-
0688
CAP 1000U 16V ELEC P5 C98
25211-
9302
RECTIFIER BRIDGE W02G BR1
27160-
0460
IC V/REG L4941BV IC15
27163-
1600
IC 75160 20 PIN IC32
27163-
1610
IC 75161 20 PIN/0.3 IC31
27250-
0410
IC UPD7210C GPIB CONT 40 PIN IC33
35358-
0580
EARTHING SPRING USB SP1
44117-
0201
PCBASS SM I/F LAN/USB/RS QL S
PCB ASSEMBLY – SM - I/F – LAN/USB/RS
Part No. Description Position
22225-
1000
SWITCH SM PUSH 'NB' SW1
23101-0
330
RES SM0603 33R0F R58-60
23105-
0000
RES SM0805 ZERO OHM R1
23105-
0330
RES SM0805 33R0F W1 R7,R9
23105-
0470
RES SM0805 47R0F W1 R15,R22
23105-
1100
RES SM0805 100RF W1 R23,R25-27,R32,R34,R44-
45
23105-
1110
RES SM0805 110RF W1 R3,R5
23105-
1470
RES SM0805 470RF W1 R12,R14
23105-
1680
RES SM0805 680RF W1 R42
23105-
2100
RES SM0805 1K00F W1 R11,R19,R40

19
PCB ASSEMBLY – SM - I/F – LAN/USB/RS continued/…
Part Number Description Position
23105-
2150
RES SM0805 1K50F W1 R20,R63
23105-
2220
RES SM0805 2K20F W1 R4,R6,R33,R38-
39,R43,R54,R62
23105-
2487
RES SM0805 4K87F W1 R46
23105-
3100
RES SM0805 10K0F W1 R2,R8,R13,R16-18,R24,R29-30,R35-
36,R41,R48-49
23105-
3470
RES SM0805 47K0F W1 R37,R47
23105-
4100
RES SM0805 100KF W1 R10,R21
23407-
0101
CAP SM0805 100PG CER NPO C1-3,C6
23407-
0180
CAP SM0805 18PG CER NPO C14-15
23407-
0220
CAP SM0805 22PG CER NPO C21,C32
23409-
0113
CAP SM1206 10NK 500V X7R C100
23411-
0475
CAP SM1206 4U7K 16V CER X7R C5
23461-
0020
CAP SM0805 100NZ 50V CER Y5V C4,C7-8,C16-20,C22-29,C33-36,
C40,C42,C52-54,C
23461-
0500
CAP SM0805 4U7 6V3 CER X5R C38-39
23559-
0010
CAP SM 100UF 6.3V AL ELEC C99
23559-
2221
CAP SM 220U 10V AL ELEC C37
23559-
3470
CAP SM 47U 16V AL ELEC C9,C12-13
23595-
0010
CAP SM-A 1U0M 16V TANT C10-11,C31
23595-
0110
CAP SM-B 10UM 10V TANT C30,C107
25021-
1010
DIO SM BAS21 200V/200mA SOT23 D1
25061-
0304
LED SM0805 RED LED1-2
25340-
1000
TRAN SM PNP BC859C SOT23 Q1
25377-
1000
TRAN SM NPN BC849C SOT23 Q3
27160-
1030
IC SM V/REG LM1117-3V3 SOT223 IC4
27163-
1232
IC SM 232A RS232 DRIVER IC1
27246-
0140
IC SM 74LCX14 SO14 IC5
27250-
2260
IC SM DP83848C PHYTER LQFP48 IC3
27250-
2340
IC SM MCU LPC2368 TFBGA100 IC2
28500-
2040
XTAL SM 12MHZ 30/50PPM 16PF XTL1
28515-
1000
OSC MODULE SM 50MHz ACT9300 OCS1
35594-
0290
PCB I/F LAN/USB/RS232 QL
PCB ASSEMBLY – KEYBOARD SINGLE
Part Number Description Position
20612-0012 WASHER FIBRE 15.88MM OD FIT BETWEEN REAR OF PCB AND ENC1.
ENC1 TO HAVE TAB BENT FLAT.
22224-0020 ENCODER ROT 24 POSITION ENC1