Texmate, Inc. Tel. (760) 598-9899 • www.texmate.com
PM-35U Manual (P1)
Page 3
described in the text.
NOTE: Use of these application circuits is entirely at the risk and
responsibility of the user and any user modification of the meter may at
the discretion of Texmate, void the warranty. (See rear page for user's
responsibility and warranty details) The following legend applies to
all application circuits: 1) optional component positions are shown in
dotted lines; 2) internal solder junctions are shown by for a closed
junction or for an open junction; 3) calibration voltages as mea
-
sured by an external user supplied voltmeter are shown by
Typical Application Connections
The PM-35U may be used in a wide variety of configurations.
The following circuits illustrate some of the possibilities and
demonstrate the exceptional versatility of Texmate products.
Components called for in the applications which are not part
of the standard meter may be supplied by the user or in some
cases purchased from Texmate. The circuit diagrams explain
the basic pinout connections required for each application.
Unless otherwise specified, the diagrams will show the com
-
ponent values and solder junctions that would normally be
installed on a standard 2V range meter. For those applications
which have alternative ranges and/or input configurations,
the required component values and any modifications are
F.S. In
Rs External
Resolution
20A
0.01
10mA
2A
0.1
1mA
F.S. In
Rs Internal
Resolution
200mA
1
100µA
20mA
10
10µA
2mA
100
1µA
200µA
1k
100nA
F.S. In Rs+R
T
Resolution
200 100 100m
2k
1k
1
20k
10k
10
200k
100k
100
2M
1M
1k
20M
10M
10k
F.S. In
R1
R2 Resolution
200mV omit
omit
100µV
2V
omit
omit
1mV
20V 9M 1M 10mV
200V
10M
100k
100mV
1200V 10M
10k
1V
VOLTAGE RANGE CHANGE
CURRENT RANGE CHANGE (*)
Use 200mV F.S. meter for minimum voltage drop.
OHMMETER RANGE CHANGE
Useful Tables
DIFFERENTIAL METER - 200mV RANGE,
>2V Range, or EXTERNAL REFERENCE
200mV Range : 1) Change R6 from 470k to
47k, ±5%; 2) Change R9 from 18.2k to 26.7k,
±1%; 3) Remove R8 (9.53k) and short with a
jumper; 4) It is rec om mended that C4, C5 and
C7 be changed to 0.22mF; 5) Adjust R10 until
CV1= 100mV.
>2V Range: Install R1 and R2 as specified
under section titled Useful Tables.
External Reference: 1) Cut open solder junc
-
tion J1; 2) Con nect Pin E to Pin K;3) Connect
moving arm of RB to Pin D.
SIMULTANEOUS VOLTAGE AND CURRENT
MEAS URE MENT
1) Connect meter as for 200mV voltmeter for
minimum drop on Rs or R2. Use Rs externally
for currents greater than 200mA; 2) Install R1,
R2, and Rs as specified under section titled
Useful Tables. NOTE: Rs must be located in
low side of the current loop and Signal Low
Input Pin J of voltmeter must not be grounded.
If it is necessary to install Rs on the high side
of the current loop, the ammeter must be op er-
at ed from an isolated power supply.
RATIOMETRIC VOLTMETER
Reading =(V1 ÷ V2) x 1000 where -2V ≤ V1 ≤
+2.8V and +100mV ≤ V2 ≤ +4V and 0000 <
Reading <1999. Cut open solder junction J1.
DIFFERENTIAL RATIOMETRIC OHM ME TER
1) Select RL so that the voltage drop across RL
is not less than 3V for that range in F.S., or use
a 3.9V Zener diode instead of RL; 2) Install RS
and RT as specified under sec tion titled Useful
Tables; 3) Cut open solder junction J1.
SINGLE-ENDED CURRENT METER
1) Connect meter as for 200mV voltmeter;
2) Install Rs. NOTE: Rs must be externally
mounted when current is greater than 200mA.
Standard values for Rs are speci fied under
section titled Useful Tables. For all other
ranges, Rs may be internally mount ed in the
R2 po si tion.
8
9
10
6
J
K
L
5VDC
-
+
F
+
-
CURRENT
SHUNT
RESISTOR Rs
R
2
Vo
R LOAD
L
8
9
10
6
J
L
5VDC
-
+
F
R1
R2
7
H
E
4
Cv1
D
R10
2k
R9
18.2k
R8
9.53k
C4
C6
R6
470k
K
J1
-
+
+5V
+
-
Vo
C
C
R
R
R
R C
C V
1 2 V
+ V
. C V
-1.5V o +2.8V
R
R
R
R C
V
2V
V
2V
R
R
R
C
V
V
V
8
9
10
6
J
K
L
5VDC
-
+
F
4
E
CUT J1
OPEN
D
3.9 V ZENER
R (CURRENT LIMITING)
L
DEVICE
UNDER
TEST
Rx
Rs
STANDARD
R
T
8
9
10
6
J
K
L
5VDC
-
+
F
V1
4
E
V2
+
-
+
-
CUT J1
OPEN
D
8
9
10
6
J
K
L
F
CURRENT
SHUNT
RESISTOR
Rs
R2
Vo
8
9
10
6
J
K
L
5VDC
-
+
F
R1
R2
R
LOAD
L
AMMETER
7
+
-
VOLT
DO NOT GROUND THIS WIRE
VOLTMETER
H
MEASURE TEMPERATURE DIFFERENCE
Meter Reading =199.9˚C Max. where
-50˚C≤(T1, T2)<+150˚C.
5VDC POWER SUPPLY MONITOR
Install R1 and R2 with component
values shown.
7VDC TO 20VDC POWER SUPPLY MONITOR
Install R1 and R2 with values shown.
8
F
9
10
6
J
K
L
820
�
820
�
T1
LM135
T2
LM135
5VDC
-
+
8
9
10
6
J
K
L
-
+
F
R1
R2
7
H
9M
1M
Ω
Ω
LM341P5V
7 ~ 20VDC
0.1 F
μ
8
9
10
6
J
K
L
5VDC
-
+
F
R1
R2
7
H
9M
1M
�
�
