Technical Description
Gasman II Portable Gas Detector
Crowcon Detection Instruments Limited
2 Blacklands Way
Abingdon Business Park
Abingdon
Oxfordshire
OX14 1DY
United Kingdom
Contents
Contents Page 1
Functional Description Page 2
- System Overview
- Gasman II Block Diagram
- Gasman II Circuit Description
Appendix A - Schematic Diagram (Sheet1) Page 5
Appendix A - Schematic Diagram (Sheet2) - Toxic Page 6
Appendix A - Schematic Diagram (Sheet2) - Flammable Page 7
Appendix A - Schematic Diagram (Sheet2) - Oxygen Page 8
Appendix A - Schematic Diagram (Sheet3) Page 9
Appendix A - Schematic Diagram (Sheet4) Page 10
Appendix B - Parts List (Sheet 1) Page 11
Appendix B - Parts List (Sheet 2) - Toxic Page 12
Appendix B - Parts List (Sheet 2) - Flammable Page 13
Appendix B - Parts List (Sheet 2) - Oxygen Page 15
Appendix B - Parts List (Sheet 3) Page 16
Appendix B - Parts List (Sheet 4) Page 17
Page 2
Page 2
Page 3
1
Functional Description
2
System Overview
The GasmanII Portable Gas Detector system is designed to detect the presence of toxic or flammable gases or the
absence of life supporting gases . As an option it may be fitted with a low po wer transmitter PCB to perm it the use of a
body-worn Vibrating Pager Unit.
The standard Gasm anII Port able Gas Detec tor m onitors the level of a par ticul ar gas in the atm os phere and provi des b oth
an audible and a visual alarm should the gas levels become unacceptable. When fitted with the optional low power
transmitter PCB the un it also em its a 418MHz RF c arrier wave that is 'On-O ff-Key' (OO K) modul ated at about 10H z. It is
this signal, which is only emitted whi le the alarm condition exists, that the Gasm anII Vibrating Pager Un it intercepts and
produce a pulsing vibration to augment the audible and visual alarms provided by the GasmanII Portable Gas Detector.
Gasman II Block Diagram
The circuit consists of the function al blocks as shown in Figure 1 b elow and a com plete unit is assembled from 3 PCBs,
with an optional fourth PCB, as sho wn in the appendic es. Each of the three distinc t gas types requ ires a specif ic type of
gas sensor, signal conditioning circuitry and calibration information. All of the gas sensors share a similar mechanical
design and are plugged into a sm all daughter board at the top of the un it. The output signal from the var ious types of
sensor is diff erent and each requir es a correspon ding signal conditionin g amplifier to interf ace the s ignal to t he comm on
CPU section. The calibration information is stored in non-volatile memory within the unit and is factory set.
The CPU is powered in a low-power state at all times that batter ies are present and c ontrols the e lectron ic sw itch to a ppl y
power to the rest of the circuitry when one of the front-panel mounted buttons is pressed. Once powered the unit
continuously monitors the gas level comparing it with preset alar m levels and, should an alarm level be exceeded, the
buzzer and the LED operate to provide both audible and visual warnings. The two signals that drive the LEDs are
combined on the optional low-po wer transmitter PCB to form a 10Hz signal that is used to m odulate an RF Monolithics
transmitter module.
gas
sensor
electronic
switch
analogue
signal conditioning
LCD display
cpu
(ROM & RAM)
buzzer
LEDs
low
power
txmtr
(optional)
Figure 1: Gasman II Block Diagram
3
Gasman II Circuit Description
The following description of the circuit refers to the schematics shown in Appendix A.
Sheet 1 (CPU/Display PCB)
The CPU is at the hear t of the unit and contains the o perating program stored in O TPROM and a quantity of RAM for
general variable storage. Q 1A and IC3 provide the elec tronic switch shown in the Block Diagram above and these t wo
components form a switched +3 V supp l y that is us ed to po wer various circ uit sec tions. IC2 is an EEP ROM and is used to
store data relating to c onf iguration and calibrat ion while IC4 provides a CPU rese t/watc h dog f unc tion . Un der the c ontr ol of
one of the CPU I/O lines Q 1B is used to switch the LCD backlight o n and off . S1 and S2, the t wo user push- buttons, are
used to control the u nits function. Two crystals, X 1 and X2, provide the clock s ignal for the CPU with X1, at 2.51MHz,
providing the frequency for normal operation and X2, at approximately 32kHz, providing the clock signal for the CPU when
not in full operation. The connections to the Main PCB are made throu gh connectors J1 and J2 with J P4 providing the
connection to the optional low-power transmitter PCB.
Sheet 2 (Main PCB) - Toxic
This PCB contains th e 3 batteries use d to provide po wer to the unit, the analogue signal conditioning f or the g as sensor
and also the 'buffers' for driving the buzzer and the LEDs.
IC2 provides the nec essary amplif ication and level sh ifting to enab le the out put from the gas sensor to be c oupled to the
CPU ADC input. The u nit is conf igured using a c ustom PC applicat ion and c omm unication is accom plished via connector
J4. IC3 (comparator) is used to extract the data sent by the PC from the c omm on 'signal' wire and Q2 is used to impr ess
the data sent by the Gasman II to the PC onto the 'signal' wire. Varistor , RV1, pro vides prot ectio n agai nst ESD tra nsie nts.
IC3 (op-amp) provides a control loo p for powering the sensor and is arranged t o maintain constant operating con ditions.
Header, H1, is a small plug-in PCB containing resistors that set the offset and gain of the sensor signal conditioning
amplifier. IC1(A/B) is used to pr ovi de a bo osted dr ive sig nal during a n alar m condition for the bu zzer and t wo LEDs . IC 1B
is wired to provide a differentia l drive to the bu zzer and thus ge nerates a gre ater sound leve l. IC1A provides the drive to
the LEDs and also the drive to Q2 as mentioned above. Q1 is a depletion-mode FET, i.e. its channel conducts until biased
off, which is used to short the sensor term inals when the unit is s witched off. T he connections to the CPU/D isplay PCB
are made through connectors J1 and J2 while J3 provides the connection to the Sensor PCB.
Sheet 2 (Main PCB) - Flammable
This PCB contains the 3 batteries, NiCAD t ypes, used to provide power to the unit, the ana logue signal condition ing for
the gas sensor and als o the 'buffers' f or driving the buzzer and the LEDs. An additional function fitted to the PCB is the
ability to charge the NiCAD batteries.
IC5 and IC2 provide the neces sar y am plific ation an d lev el shif ting to enabl e the ou tput from the gas sens or t o be c ouple d
to the CPU ADC input. The CP U provides a method of 'auto-zeroing' the output from the sensor b y providing a variable
M/S ratio PWM signal to the base of Q3. The effect of this, once smoothed by R4 and C5, is to provide a variable
'calibration voltage' at TP3. FET, Q4, is used to change the gain of the signal-conditioning amplifier under CPU control.
The unit is configur ed using a cus tom PC applic ation and comm unication is acc omplished vi a connector J4 a nd varistor ,
RV1, provides protection against ESD transients. IC3 in conjunction with FET, Q1, provide a low battery protection system
and remove power to the PCB when the b attery vol tage falls below a bout 2.3V. IC4, in c onjunction with FET , Q2, prov ide
a power supply to the sensor that may be turned off b y the CPU to save battery power. IC1(A/B) is used to provide a
boosted drive signal dur ing a n alarm condition for th e bu z zer a nd t wo LE Ds . I C1B is wired to pro v ide a differentia l dr i ve to
the buzzer and thus gen erates a great er soun d lev el. IC1 A prov ides t he dri ve to th e LEDs and a lso pro vides t he tra nsm itdata signal to the PC over the communications link. The connections to the CPU/Display PCB are made through
connectors J1 and J2 while J3 provides the connection to the Sensor PCB.
Sheet 2 (Main PCB) - Oxygen
This PCB contains th e 3 batteries use d to provide po wer to the unit, the analogue signal conditioning f or the g as sensor
and also the 'buffers' for driving the buzzer and the LEDs. An additio nal function is th e provision of an NTC therm istor to
permit the ambient temperature to be monitored.
IC2 provides the nec essary am plification and level s hifting to e nable the out put from the gas sensor to be coupled to the
CPU ADC input. The u nit is conf igured using a c ustom PC applicat ion and c omm unication is accom plished via connector
J4. IC3 is used to extract the data sent by the PC fr om the c omm on 'signal' wire and Q2 is us ed to im press the data sent
by the Gasman II to the PC onto the 's ignal' wire. Varistor, VR2, provides prot ection against ESD tra nsients. IC1(A/B) is
used to provide a bo osted dri ve signal d uring an al arm condition for the buzzer and t wo LEDs. IC1 B is wired to pro vide a
differential drive to t he b u zzer and thus gen er ates a gr ea ter so u nd le vel . IC1 A prov id es the dr ive to the LEDs and als o t he
drive to Q2 as mentioned above. Q1A and TH1 provide th e ambient temperature m onitoring capability with the vo ltage
across the thermistor being fed to a CPU ADC input. The connections to the CPU/Display PCB are made through
connectors J1 and J2 while J3 provides the connection to the Sensor PCB.
4
Sheet 3 (Sensor PCB)
This is a simple PCB that plugs into the Main PC B via connector J 1. It contains the buzzer and the t wo LEDs along wi th
two sites for a gas sensor. The two sites are necess ary to accomm odate the two slightl y different ph ysical shapes of the
gas sensors and are overlaid so as to position each of the gas sensor types in the same place when fitted.
Sheet 4 (Optional Low-Power Transmitter PCB)
This simple PCB p lugs into the C PU/Display PC B via J1 whic h carries bot h power and the two LED c ontrol sign als. The
LED control signals ar e 'ORed' together on t his PCB to provid e a 10Hz modulatio n waveform. This waveform is used to
power the transmitter module, IC1, using FETs Q1 and Q2.
Appendix A - Schematic Diagram (Sheet 1)
5
D
12345678
WITHOUT REFERENCE TO CERTIFYING AUTHORITY -
Any resistor may be substituted by an
alternative whose resistance is greater, or >=1k.
Any capacitor may be substituted by an
alternative whose capacitance is lower.
R15
3k9
3
8
3
7
3
6
3
5
3
1
3
2
3
3
1
3
7
9
3
4
C4
1uF
C3
Vdig
10nF
R10
100k
1234567891011
J2
3V
SensorSleep
SparePort1
SparePort2
SparePort3
/PotDrive
Vdig
/Alarm-LED-1
/Alarm-LED-2
SensorSignal2
VdigSwitched
IC3
TC55
IMT1
1
6
1 2
5 Q1A
R1
3k9
12345678910111213141516171819202122232425262728293031
J3
LCD CONNEXION 2x16
S1S21g1f1a
1b
DPT12g2f2a2b
DPT23g3f3a3b
S8S7S6S5S4
S3
S2S13a3b3c3d3e3f3g
40
45
46
SEG139P5-1
P5-241P5-342P5-443P5-544P5-6
P6-047P6-148P6-249P6-350P6-451P6-552P6-653P6-754P7-055P7-156P7-257P7-358P7-459P7-560P7-661P7-762P8-063P8-164P8-265P8-366P8-467P8-568P8-669P8-770P9-071P9-172P9-273P9-374P9-475P9-576P9-6
COM
1
WKP7/P5-7
COM
2
COM
3
COM
4
V
3
V
2
V
1
MD0
VCC
VCC
TXD
RXD
P2-7
90
89
21
/SwitchDrive
TxD
RxD
C2
10uF
3
C1
10uF
3V reference
1
TP3
AN0
93
TP4
R2
3k9
AN2
AN1
95
94
1
C5
100nF
SensorSignal1
AN8
AN3
1
96
Potentiometer
2
SensorSignal2
Vdig
3cS83dS73e2cS6
COMMON
DPT12a2b2c2d2e2f2gDPT2
AN11
AN10
AN9
4
3
1
TP5
R19b
0R
0R
R19a
VdigSwitched
R17
R16
22
10k
SCK
10k
6
IC2
8WP 7A0 1
C
2d
S52eS41c1d1eS3
1a
1b1c1d1e1f
P3-0/SCK1
P3-1/SI1
P3-2/SO1
23
24
1
TP6
DATA
5
4
CLK
/A12GND
DATA
VCC
A2
3
24C16
1g
77
2k x 8
EEROM
32
VdigSwitched
TP7
78
SEG40/P9-7
IC1
H8/3834
R3
3k9
R4
3k9
1
TP8
TP9
BatteryState
/PotDrive
BatCheck
1
19
100
97
91
P2-5
P2-620P2-014P2-115P2-216P2-3
PB7/AN7
PB6/AN699PB5/AN598PB4/AN4
P4-3/IRQ0
AVCC
92
3V
1
SCK
17
P3-6
P3-5
P3-4
P3-3
P3-7
28
27
26
25
29
SensorSleep
SparePort1
SparePort2
Vdig
R20
Always Low for Gasman II
B
Backlights
TP13
R6
150R
1
Vdig
IMT1
4
3
TP11
88
P4-0
R14
1k
1k
D3a D3b
R5
150R
2 Q1B
3k9
R13
1
18
P2-4
80
S2
S1
1
TP15
D1
GF1J
P1-1
P1-0
81
Vdig
Vdig
P1-4/PWM
P1-3
P1-2/TMOFH
84
83
82
sound
PWM
SparePort3
R9
3k9
R8
3k9
1
TP16
D2
GF1J
R18
100R
VCC5GND
WDI
/RESET
IC4
4
1
D3
1SS355
R7
27k
1
TP14
12
/RES
P1-7
P1-6
P1-5
87
86
85
/SounderOn
/Alarm-LED-1
/Alarm-LED-2
C6
100nF
2
-25-CYT
/MR
MAX6316
3
C9
1uF
Force Reset
by shorting
across C9
5
AVS
S
9
TP1
GND
3
0
GND
1
1
1
OSC
2
1M
R11
X1 2.51 MHz
1
0
OSC
1
7
X
2
X2
32.768kHz
8
X
1
TEST
6
A
Crowcon Ltd
PCB issue: 1V1
PCB No: PC2065 issue 1V1
Filename: G2-CPU2
GASMAN 2 CPU (DISPLAY) BOARD
C 2648-CD 1V1
Date: December 19, 1999 Sheet 1 of 1
Size Document Number REV
Title
2
1 3
C8
15pF
C7
15pF
R12
10k
3V
TxD
RxD
PWM
Potentiometer
sound
/SounderOn
SensorSignal1
123456789
10
J1
11
D
outingnd
123
4
JP4
Connections to optional daughter board:
Vdigswitched
/Alarm-LED-1
/Alarm-LED-2
Radio transmitter for optional Vibrator
C
B
A
TC55
1 5
3V reg
MAX
8 7 6 5 4 3 2 1
6316
Appendix A - Schematic Diagram (Sheet 2) - Toxic
6
J3-9
right
angled
board
12345678
1
TP1
1
1M
R11
Sounder+
Y1 9Y2 7Y3 5Y4
A1
IC1B
11A2 13A3 15A4 17
sound
Speaker Drive
Vdig
GND
C10
10uF
VCC
C16
100nF
J3-4
1
TP2
1
Q1
Sounder-
3
D
J3-2
J3-6
J3-5
1
1
1
Counter
Ref
Sense
1
2
3
J177
Vdig
TP3
/OE
74HC240
19
/SounderOn
J3-7
J3-3
1
1
TP5
TP6
1
1
150R
150R
1
R32
R31
1
TP4
1
Y118Y216Y314Y4
A1
IC1A
2A2 4A3 6A4 8
/Alarm-LED-1
/Alarm-LED-2
R14
1M
R15 10k
Sounder-
J3-8
1
TP21
/TxD
12
TxD
3
G
/OE
74HC240
1
Comms
"S7"
12
DS
C
J177 (top view)
H1
1
1
TP7
TP14
C17
1
HEADER
6
C4
10nF
VdigFilt
1
1
100pF
TP15
R8
4k7
TP12
/SensorSleep
C2
100pF
2
Sense
3
SensorSignal1
R10 4k7
6
8
71
2
TP13
C5
1
R5
100k
4
C13
1nF
3
1
1nF
3
R7
C7
IC2
R6 100k
5
10k
100pF
LTC1152
5
4
C8
C9
C11
8
3V
C12
1nF
100pF
100pF
10nF
B
WITHOUT REFERENCE TO CERTIFYING AUTHORITY -
Any resistor may be substituted by an
alternative whose resistance is greater, or >=1k.
Any capacitor may be substituted by an
alternative whose capacitance is lower.
7
A
v0
Crowcon Ltd
GASMAN 2 TOXIC BOARD
changed without reference to DEMKO A/S
This component / distance must not be
*
B 2646-CD-PROD 2v0
Size Document Number REV
Title
Filename: G2-Tox2
Date: December 20, 1999 Sheet 1 of 1
PCB Issue: 2v0
GND
sound
/SounderOn
SensorSignal1
123456789
J1
VR1
10k
3V
RxD
TxD
Potentiometer
PWM
10
Cal / Zero pot
E03556
11
J2
To CPU board
D
1
2
J3X
Short during Reset
TEST JIG
10k
R23
The link between
R23 allows s/w to tell
this is an issue 2 PCB
/PotDrive
/Alarm-LED-1
/Alarm-LED-2
SparePort1
SparePort2
Vdig
SensorSignal2
/SensorSleep
123456789
Counter
(Sensor is
on other PCB)
C14
1nF
R3
to re-initialise s/w
SparePort 1 & 2
this is a Toxic board.
enables the s/w to tell
VdigSwitched
GND
10
11
3k9
1
TP9
RxD
Vdig
C
TP8
D2
2
Ref
1
1SS355
C15
1
TP16
R13
/TxD
1
TP20
R4
10k
1
C
TP19
Q2
BC849
1
TP18
D4
R9
1k
6V2
"2C"
BE
Vdig
BC849
C3
10nF
C6
10uF
10uF
1nF
3k9
R1
1
TP10
234 8
TP11
1V2
C18
100nF
R2
3k9
R25
R
1
R
R24
*
**
0W4
D3
6V2
*
F1
IC3
7
R12
10k 1
MAX951
spare comparator
6
5
1V2
1
VdigFilt 1
3
TP17
2
FLT1
Vdig
B
R20 >=200R
*
1.5mm segregation
J4
RV1
VARISTOR
1
2
125mA C1
8 7 6 5 4 3 2 1
1
B3
2B14.5V
1
2B21
2
A
3 alkaline cells PCB No: PC2069
Appendix A - Schematic Diagram (Sheet 2) - Flammable
7
D
J3-9
12345678
Vdig
C2
VCC
C10
J3-4
right
angled
board
1
1
TP211TP22
1
Sounder+
Sounder-
Y1 9Y2 7Y3 5Y4
A1
IC1B
11A2 13A3 15A4 17
sound
Speaker Drive
1
GND
TP19
10uF
100nF
3Vswitched
5
OUT
VIN
IC4
1
Vdig
Pellistor power supply
R22
1M
3
19
/SounderOn
C9
100nF
C4
10uF
4
GND
2
TP1
R19
R
Q2
/OE
BP
/SHDN
3
1
SparePort3 1 2
VR1
TP12
150R
R31
TP20
74HC240
C11
10nF
MAX8878
3
R18
10k
J3-7
J3-3
J3-8
1
1
1
TP10
1
1
150R
R32
1
TP13
1
12
Y118Y216Y314Y4
A1
IC1A
2A2 4A3 6A4 8
1
TxD
/Alarm-LED-1
/Alarm-LED-2
BSS123
R
D1
1SS355
Cal / Zero pot
10k
R23
J3-1
1
3Vswitched
1
TP9
/OE
74HC240
Comms
BoostedTxD
1
TP2
D2
J3-2
1
C3
FlamBridge
1
1SS355
A
Crowcon Ltd
GASMAN 2 FLAMMABLE BOARD
changed without reference to DEMKO A/S
Title
B 2V1
Date: December 20, 1999 Sheet 1 of 1
Size Document Number REV
*
WITHOUT REFERENCE TO CERTIFYING AUTHORITY -
Any resistor may be substituted by an
Any capacitor may be substituted by an
alternative whose capacitance is lower.
alternative whose resistance is greater, or >=100R.
PCB No: PC2067 issue 2v1
Filename: G2FlamV2
6 ohms
N-channel
Vdig
0R
R1
2
5
Q1
4
3
C1
Vin
>=100R
R24
*
F1
125mA
B1
1
VIN
1uF
3 1
2
RESET
D6
D5
2
NDC632P
GND
<=6V2
<=6V2
1
61
NDC
IC3
MAX6327
1
2B21
dss
632P
ddg
B3
p-channel
BatTypeSense
R21
2
1k
5
1234
top view
3k9
1
TP18
C7
1nF
TP17
4k3
>=200R
*
R20
*
B
"ACGF"
typ. marking:
C6
10nF
Vdigswitched
IC2
5
TP4
R10
d
SA
0W4
TP5
R27
10R
*
1
D7
SensorSignal1
1
MAX4040
2
10k
3
4
1
1
R13
TP6
10k
R12
4k7
Q4
gs
BSS123
R11
LK2
RESET
*
>=750mAD8>=750mA
This component / distance must not be
10k
R14
3
BSS123
1 2
R8
R
0R
D10
SparePort1
1 2
*
D9
GF1J
C
MAX4040
1
TP7
1
1nF
TP8
Vdigswitched
R7
c
MMST2222A
D4
<=6V2D3<=6V2
IC5
5
1M
TP16
"RIP"
MAX4040
R15
R5
R9
2
3
4
R17 1M
1
1
82k
82k
R16
FlamBridge
FlamRef
R6
11k
1
10k
TP3
R3
10k
1
C5
2u2
TP15
R4
10k
Q3
MMST2222A(9.6kHz)
1
1
TP14
TP23
R2
PWM
be
3V
GND
sound
123456789
J1
RxD
TxD
Potentiometer
/SounderOn
SensorSignal1
PWM
RESET
SparePort4
10
11
D
/PotDrive
/Alarm-LED-1
/Alarm-LED-2
123456789
J2
To CPU board
SparePort2
SparePort1 HI to boost gain
Vdig
VdigSwitched
SparePort3
BatTypeSense
SensorSignal2
1
2
RV1
GND
10
11
J2-8, J2-9 are connected to help CPU tell it’s
connected to a Flammable PCB.
R23 tells processor this is an issue 2 PCB.
C
1.5mm Segregation
1
2
J4
B
K
"ZS7"
D7,D8
ANC
LK1
8 7 6 5 4 3 2 1
Charging circuitry
A
Appendix A - Schematic Diagram (Sheet 2) - Oxygen
58
D
J3-9
J3-4
12345678
1
1
1
TP11TP2
1M
R12
Sounder+
Sounder-
Y1 9Y2 7Y3 5Y4
A1
IC1B
11A2 13A3 15A4 17
sound
J3-7
1
1
TP31TP4
R
R31
1
TP5
3
/OE
74HC240
IC1A
2A2 4A3 6A4 8
19
Speaker Drive
/SounderOn
/Alarm-LED-1
Vdig
GND
C10
10uF
VCC
C4
100nF
TH1
NTC
10k
1
Temp
VR1 10k
Cal / Zero pot
10
11
To CPU board
D
10k at 25C
2
C19
1nF
R23 permits s/w
J2
TP13
R8
Q1A
IMT1
1
6
1
3V
1
5
TP14
10k
R9
Temperature sensor
SparePort1
short during
Reset to
re-initialise
software
"TEST JIG:"
1 2
J3
3V
GND
sound
123456789
J1
RxD
TxD
Potentiometer
/SounderOn
SensorSignal1
J3-3
1
1
R
R32
1
TP6
12
Y118Y216Y314Y4
A1
/OE
74HC240
1
TxD
Comms
/Alarm-LED-2
is an issue
2v0 board
to tell this
R23
10k
Linking SparePort 1 & 2
allows s/w to tell this
/PotDrive
/Alarm-LED-1
/Alarm-LED-2
SparePort1
SparePort2
Vdig
SparePort3
123456789
J3-5
J3-8
J3-6
1
1
OxySignal
J5
1
TP12
is an Oxygen board
VdigSwitched
GND
Temp
10
11
TP9
270k
R1
C
3V 1
SensorSignal1
3
2
FLT1
C3
10nF
1
TP7
R18
IC2
7
OP191
TP10
2k7
26 3
1
TP11
R6
TP15
TP22
1
123
IC3
7
TP16
RxD
R10
4
1
2k7
R11
OxySignal
1
1V2
6
5
1
1V2
10k
1
R2 1k
1
TP8
C9
1nF
R3
2k7
R5
2k7
1
2
Double
gain
C
B
WITHOUT REFERENCE TO CERTIFYING AUTHORITY -
Any resistor may be substituted by an
alternative whose resistance is greater, or >=1k.
TP21
1
10nF
/TxD
10k
R4
100R C5
D1
1SS355
Vdig
*
*
D4
6V2
D3
1
TP17
4 8
*
MAX951
Vdig
B
1
TP20
Q2
BC849
TP19
1
R7
3k9
1
TP18
6V2
*
R20
>=200R
VR2
1.5mm segregation
1
2
J4
0W4
VARISTOR
A
Crowcon Ltd
GASMAN 2 OXYGEN BOARD
This component / distance must not be
changed without reference to DEMKO A/S
Title
B 2645-CD 2v0
Date: December 19, 1999 Sheet 1 of 1
Size Document Number REV
*
Any capacitor may be substituted by an
alternative whose capacitance is lower.
PCB issue: 2v0
PCB No: PC2068
Filename: G2-ox2
c b e(6)
B3
c(1)be
Note:
one half of
Q1 is spare.
2
(symmetrical)
8 7 6 5 4 3 2 1
3 alkaline cells
BC849
C
"2C"
BE
IMT1 dual PNP xistor
C1
10uF
Vdig
C2
10uF
*
F1
125mA
1
2B14.5V
1
2B21
A
Appendix A - Schematic Diagram (Sheet 3)
9
B
S1
C
Toxic
123
sensor
Flam
sensor
123
S2
D
12345678
1nF
C1
A
Filename: G2-sens
PCB no: PC2066(bottom view)
Crowcon Ltd
Gasman 2 Sensor Board Issue V4
Size Document Number REV
Title
AA
Date: December 19, 1999 Sheet 1 of 1
R1
>10R
LS1
R2
43R
1.5mm SEGREGATION
Sounder+
1
J1-9
Sounder1
AT-01
J1-4
Counter
Ref/Bridge
1
1
J1-5
J1-2
Sense
1
J1-6
3V
1
J1-1
S1 and S2 are overlaid
because only 1 is
fitted at a time.
D1
LEDD2LED
Alarm-LED-1
1
J1-71J1-3
GND
Alarm-LED-2
1
J1-8
1 = Counter
2 = Ref
3 = Sense
TOXIC:
3
21
Toxic / Oxygen sensor
1
3
2
(bottom view)
Flammable sensor
8 7 6 5 4 3 2 1
D
C
B
A
Appendix A - Schematic Diagram (Sheet 4)
10
B
ANTENNA
1
MOD
2
POS
C
C3
1nF
R1
0R
4
ANT
IC1
HX1003
3
0
V
D
12345678
A
Filename: G2radio
PCB number: PC2128
Radio Transmitter Daughter Board
Crowcon Detection Instruments Ltd
A 1.0
Date: December 19, 1999 Sheet 1 of 1
Size Document Number REV
Title
2
5
Q1
4
3 1
Vdigswitched
/Alarm-LED-1
123
4
J1
2
5
Q2
4
3 1
/Alarm-LED-2
C2
C1
1nF
10nF
8 7 6 5 4 3 2 1
D
To Display board.
C
B
A
Appendix B - Parts List (Sheet 1)
This appendix gi ves the parts list for the Gasm anII Porta ble G as Det ector CP U/displa y PCB. For each c ircuit r eference a
description of the component is given and, where appropriate, its case style is listed.
Circuit Ref. Component Description Case Style
C1 10uF 16V Tantalum Case A
C2 10uF 16V Tantalum Case A
C3 10nF 25V X7R Multi-layer Ceramic 0805
C4 1uF 16V Tantalum Case A
C5 100nF 16V X7R Multi-layer Ceramic 0805
C6 100nF 16V X7R Multi-layer Ceramic 0805
C7 15pF 25V COG Multi-layer Ceramic 0805
C8 15pF 25V COG Multi-layer Ceramic 0805
C9 1uF 16V Tantalum Case A
D1 GF1J SMA
D2 GF1J SMA
D3 1SS355 SOD123
IC1 Motorola H8/3834 100PQFP
IC2 Microchip 24C16 SO8
IC3 TC55 3V Regulator SOT89
IC4 MAX6316 SO8
Q1 IMT1 SOT23-6
R1 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R2 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R3 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R4 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R5 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R6 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R7 27k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R8 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R9 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R10 100k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R11 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R13 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R14 1k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R15 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R16 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R17 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R18 100R 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R20 1k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
S1 Push Switch Omron B3S-1000 N/A
S1 Push Switch Omron B3S-1000 N/A
X1 2.51MHz Crystal N/A
X2 32.768kHz Crystal N/A
11
Appendix B - Parts List (Sheet 2) - Toxic
This appendix gives the parts list for the GasmanII Portable Gas Detector Main PCB - Toxic version. For each circu it
reference a description of the component is given and, where appropriate, its case style is listed.
Circuit Ref. Component Description Case Style
C1 10uF 16V Tantalum Case B
C2 100pF 25V COG Multi-layer Ceramic 0805
C3 10nF 25V X7R Multi-layer Ceramic 0805
C4 10nF 25V X7R Multi-layer Ceramic 0805
C5 1nF 25V X7R Multi-layer Ceramic 0805
C7 100pF 25V COG Multi-layer Ceramic 0805
C8 100pF 25V COG Multi-layer Ceramic 0805
C9 100pF 25V COG Multi-layer Ceramic 0805
C10 10uF 16V Tantalum Case B
C11 10nF 25V X7R Multi-layer Ceramic 0805
C12 1nF 25V X7R Multi-layer Ceramic 0805
C13 1nF 25V X7R Multi-layer Ceramic 0805
C14 1nF 25V X7R Multi-layer Ceramic 0805
C15 1nF 25V X7R Multi-layer Ceramic 0805
C16 100nF 16V X7R Multi- layer Ceramic 0805
C17 100pF 25V COG Multi-layer Ceramic 0805
C18 100nF 16V X7R Multi- layer Ceramic 0805
D1 1SS355 SOD123
D3 6V2 1.3W Zener Diode MELF
D4 6V2 1.3W Zener Diode MELF
F1 125mA N/A
FLT1 Supply Line Filter N/A
IC1 74HC240 SSOP20
IC2 LTC1152 SO8
IC3 MAX951 SO8
Q1 J177 SOT23-6
Q2 BC849 SOT23
R1 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R2 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R3 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R4 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R5 100k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R6 100k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R7 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R8 4k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R9 1k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R10 4k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R11 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R12 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R14 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R15 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R20 330R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R23 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R24 100k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R25 510k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R31 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R32 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
RV1 Varistor 1206
VR1 10k 0.1W Preset N/A
12
Appendix B - Parts List (Sheet 2) - Flammable
This appendix gives the parts list for the GasmanII Portable Gas Detector Main PCB - Flammable version. For each circuit
reference a description of the component is given and, where appropriate, its case style is listed.
Circuit Ref. Component Description Case Style
C1 1uF 16V Tantalum Case B
C2 10uF 16V Tantalum Case B
C3 1nF 25V X7R Multi-layer Ceramic 0805
C4 10nF 25V X7R Multi-layer Ceramic 0805
C5 2u2F 16V Tantalum Case B
C6 10nF 25V X7R Multi-layer Ceramic 0805
C7 1nF 25V X7R Multi-layer Ceramic 0805
C9 100nF 16V X7R Multi-l a yer Ceramic 0805
C10 100nF 16V X7R Multi- layer Ceramic 0805
C11 10nF 25V X7R Multi-layer Ceramic 0805
D1 1SS355 SOD123
D2 1SS355 SOD123
D3 6V2 1.3W Zener Diode MELF
D4 6V2 1.3W Zener Diode MELF
D5 6V2 1.3W Zener Diode MELF
D6 6V2 1.3W Zener Diode MELF
D7 ZHCS750 SOT23
D8 ZHCS750 SOT23
D9 GF1J SMA
F1 125mA N/A
IC1 74HC240 SSOP20
IC2 MAX4040 SOT23-5
IC3 MAX6327 SOT23
IC4 MAX8878 SOT23-5
IC5 MAX4040 SOT23-5
Q1 NDC632P SOT23-6
Q2 BSS123 SOT23
Q3 MMST2222A SOT23
Q4 BSS123 SOT23
R2 4k3 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R3 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R4 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R5 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R6 11k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R7 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R9 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R10 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R11 0R 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R12 4k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R13 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R14 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R15 82k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R16 82k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R17 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R19 4k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R20 330R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R21 1k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R22 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R23 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R24 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R27 10R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
13
R31 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R32 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
VR1 10k 0.1W Preset N/A
VR2 Varistor 1206
9914
Appendix B - Parts List (Sheet 2) - Oxygen
This appendix gi ves the parts list for the GasmanII Portable Gas Detector Main PCB - O xygen version. F or each circuit
reference a description of the component is given and, where appropriate, its case style is listed.
Circuit Ref. Component Description Case Style
C1 10uF 16V Tantalum Case B
C2 10uF 16V Tantalum Case B
C3 10nF 25V X7R Multi-layer Ceramic 0805
C4 100nF 16V X7R Multi-l a yer Ceramic 0805
C5 10nF 25V X7R Multi-layer Ceramic 0805
C9 1nF 25V X7R Multi-layer Ceramic 0805
C10 10uF 16V Tantalum Case B
C19 1nF 25V X7R Multi-layer Ceramic 0805
D1 1SS355 SOD123
D3 6V2 1.3W Zener Diode MELF
D4 6V2 1.3W Zener Diode MELF
F1 125mA N/A
FLT1 Supply Line Filter N/A
IC1 74HC240 SSOP20
IC2 OP191 SO8
IC3 MAX951 SO8
Q1 IMT1 SOT23-6
Q2 BC849 SOT23
R1 270k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R2 1k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R3 2k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R4 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R5 2k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R6 2k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R7 3k9 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R8 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R9 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R10 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R11 100R 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R12 1M 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R18 2k7 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R20 330R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R23 10k 0.25W 2% 200ppm Nickel Barrier Resistor 1206
R31 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
R32 150R 0.4W 2% 200ppm Nickel Barrier Resistor 1210
TH1 NTC Th ermist or Bead
VR1 10k 0.1W Preset N/A
VR2 Varistor 1206
15
Appendix B - Parts List (Sheet 3)
This appendix gives the parts list for the GasmanII Portable Gas Detector Sensor PCB. For each circuit reference a
description of the component is given and, where appropriate, its case style is listed.
Circuit Ref. Component Description Case Style
C1 1nF 25V X7R Multi-layer Ceramic 1206
D1 High Brightness LED T1.75
D2 High Brightness LED T1.75
LS1 AT-01 Buzzer N/A
R1 47R 0.5W 5% 200ppm Metal Film Resistor N/A
R2 47R 0.5W 5% 200ppm Metal Film Resistor N/A
16
Appendix B - Parts List (Sheet 4)
This appendix gi ves the parts list f or the GasmanII Porta ble Gas Detector Low-Power Transm itter PCB. For each circuit
reference a description of the component is given and, where appropriate, its case style is listed.
Circuit Ref. Component Description Case Style
C1 10nF 25V X7R Multi-layer Ceramic 1206
C2 1nF 25V X7R Multi-layer Ceramic 0805
C3 1nF 25V X7R Multi-layer Ceramic 0805
IC1 HX1003 Transmitter Module SM-04
Q1 BSS284 MOSFET SOT23-6
Q2 BSS284 MOSFET SOT23-6
17
Loading...