Sears 5205 User manual

FULL 1 YEAR WARRANTY ON SEARS MUL TIMETER
For one year from the date of purchase, if this multi-
meter fails to work properly due to a defect In material
or workmanship, Sears will repair it, free of charge.
WARRANTY SERVICE IS AVAILABLE BY Re-
TURNING THE MULTIMETER TO THE NEAREST
SEARS STORE, OR SERVICE CENTER IN THE
UNITED STATES.
This warranty gives you specific legal rights, and you
may also have other rights which vary from state to
state.
SEARS, ROEBUCK AND CO.
Dept. 698/731 A, SearsTower, Chicago, IL60684.
Printed in KOREA
1
I Sears I
OWNERS
M NU L
34460.5205
VOM-MUL TIMETER
with BATTERY TESTER
50,000 ohms/volts de
42 RANGES
SEARS, ROEBUCK ANP CO., Chicago, IL 60684 U.S.A.

DESCRIPTION
Ideal for use where measurements must not appreciably disturb
the circuit being tested, the Model Sears 5205 features high
50,000 ohms/volt DC and 10,000 ohms/volt AC sensitivities, on
one set of voltage ranges. A second group of voltage ranges with
- sensitivities of 25,000 ohms/volt DC and 5,000 ohms/volt AC
has been designed into this instrument. Because of the avail-
ability of 12 DC voltage ranges and 8 AC voltage ranges, more
accurate readings are possible with this instrument than with
an ordinary VOM. Also included are ten DC current ranges and
five resistance ranges to assure precise current and resistance
indications. In conjunction with a power supply, the Model
Sears 5205 can be used to measu re capacitance and inductance.
Special circuitry has been included to protect the meter move-
ment against accidental overload. A mi rror arc has been pro-
vided to help eliminate parallax errors from readings. A con-
venient carrying handle built onto the case can also be used to
Position the meter for easy reading. The Sears 5205 is a quality
product in both performance and appearance.
SPECI FICATIONS
DC Voltage: ()'0.25, 2.5, 10, 50, 250, 1000 volts : 3 % of
full scale reading except 0.25, 2.5, 1000
volts ±4%; 25,000 ohms/volt.
()'0.125, 1.25, 5, 25, 125, 500 volts : 3 % of
full scale reading except 0.125, 1.25, 500
volts ±4%; 50,000 ohms/volt:
AC Voltage: 0-10, 50, 250, 1000 volts ±4% of full scale
reading; 5,000 ohms/volt.
0- 5, 25, 125, 500 volts ±4% of full scale
reading; 10,000 ohms/volt.
2
Decibels:
DC Current
-20 to +62 dB, 8 ranges.
0-25, 50 }J.A: 0-25, 5, 25, 50, 250,
500 mA; ±3 % of full scale read ing.
Ohmmeter: 0-20 Megohms in 5 ranges ±3% of full
scale arc.
1.5V AA, AAA Cell 125 mA Load Current.
1.5V C, D Cell 250 mA Load Current
9V Cell 10 mA Load Cu rrent.
One 9-volt battery (Sears Diehard AI kaline
No. 34-3094; Sears Heavy Duty No. 34-
4662) for R x 10K range; one 1.5-volt
"AA" cell (Sears Diehard AI kaline No.
34-3090) for all other ohmmeter ranges.
6-3/4" x 5" x Z'
1 lb., 4 oz.
Battery Test:
Power Supply:
Size:
Weight:
HOW TO INSTALL BATTERIES
Remove the screws in the rear cover of the case- Lift the back of
the case off the front section. Note the orientation of the bat-
teries in their compartments. When replacing the" AA"cell, the
positive (+) end of the cell should be at the end so indicated on
the case closest to the top. Be sure that the contact at each end
of the compartment makes a good connection with the metallic
battery terminal at its positive end and with the metallic
portion of the battery case at its negative end.
The 9 volt battery must be so oriented that its plus terminal is at
the connector marked "+" in the case (closest to the side) and
its minus terminal is at the connector marked "-". Slide the
battery straight down into its compartment, being sure that it is
held firmly.
3

Carefully replace the back onto the front of the case. Tighten
the screws. Do not tighten them excessively, or you will strip
the threads in the case.
CONTROLS AND JACKS
RANGE switch: Select factor and range to be measured.
V-fl.-A slide switch: Meter pointer indicates DC or AC voltage
or DC cu rrent on range selected by RANGE switch, when
slide switch is set to the V-fl.-A position. Meter pointer
indicates one half the voltage or current on range selected
by RANGE switch, when slide switch is set to the V-A/2
position,
OHMS ADJ. control: Use to set pointer to 0 (extrema right on
meter scales) on uppermost ohmmeter scale in an OHMS
setting of the RANGE switch, when test leads are in contact
with each other.
Mechanical adjust: Adjustable screw on meter movement to
set pointer to zero when leads are in contact with each other
in a DCV setting of the RANGE switch.
8 COM jack: Plug-in connection for black, negative test lead.
Ef>V-fl.-A jack: Plug-in connection for red, positive test lead,
1000V DC jack: Plug in connection for red test lead when
measuring DC to 1,000 volts. RANGE switch must be set to
the 250 & 1000 DCV position and V-fl.-A slide switch must
be set to the V-fl.-A position. Voltage will be 1/2 that noted
on meter (to 500 volts) if the V-rl.-A slide switch is set in the
V-A/2 position.
BAT_ jack: Plug-in connection for red, positive test lead when
testing batteries,
RANGE switch must be set to BAT. CHECK and slide
switch must be set to the wanted position.
4
OPERATING PROCEDURE
PRELIMINARY ADJUSTMENTS
1. Check the mechanical adjustable screw setting as follows:
a. Place the Sears 5205 tester flat on a bench:
b. Set the RANGE switch to 2.5 DCV. The V-fl.-A slide
switch can be set in either posi ti on.
c. Connect one test lead to the other,
d, Note if the meter pointer indicates exactly 0 at the
extreme left end of the black scales.
e. If it does not read 0, turn the screw on the meter move-
ments slowly until the proper 0 reading is realized.
2. Check the batteries as follows:
a Place one test lead in contact with the other.
b. Set the RANGE switch to R x 1.
c. Turn the OHMS ADJ_ control until you fi nd the position
where the pointer indicates the full scale 0 on the OHMS
scale. If this adjustment cannot be made, replace the 1.5
volt size AA cell.
d. Now set the RANGE switch to R x 10K.
e. Turn the OHMS ADJ_ control until you find the position
where the meter pointer indicates full scale 0 on the
OHMS scale .. If this adjustment cannot be made, replace
the 9-volt battery.
OPERATING SUGGESTIONS
1. Meter ranges are noted on the front panel, arou nd the
RANGE switch. DC and AC voltage as well as DC current
ranges selected through use of the knob on the RANGE
switch are those shown at this switch only when the V-fl.-A
slide switch is in the V-fl.-A position. In this case, the
sensitivity of the voltmeter is 25,000 ohms/volt DC and
5

5,000 ohms/volt AC. Voltage and current ranges are one-
half those. shown by the knob on the RANGE switch when
the V-fJ.-A slide switch is in the V-A/2 position. The sensiti-
vity of the voltmeter is 50,000 ohms/volt DC and 10,000
ohms/volt AC. Sensitivity of 25,000 ohms/volt DC and
5,000 ohms/volt AC is excellent and acceptable in most
measu ring situations. If you must have a sensitivity of
50,000 ohms/volt DC or 10,000 ohms/volt AC at any time,
set the V-fJ.-A switch in the V-A/2 position and divide all
readings by two.
2. Set the RANGE switch to the proper voltage or current range
before making measurements. If the lowest usable range is
one of those listed on the panel at the RANGE switch, set
the V-fJ.-A slide switch to the V-fJ.-A position. If it is one-
half of a range listed on the panel at the RANGE switch, set
the V-fJ.-A slide switch to the V-A/2 position. When the
V-fJ.-A slide switch is in the V-fJ.-A position, never apply
more voltage or current than the amount noted on the front
panel in each RANGE switch position. When the V-fJ.-A
slide switch is in the V-A/2 position, never apply more
voltage or cu rrent than one-half the amou nt noted on the
front panel in each RANGE switch position. When in
doubt as to the voltage or current present in a circuit
start with the highest range and set the V-fJ.-A slide switch
to the V-fJ.-A position. If the voltage or current is of such
magnitude as to be measurable on a lower range, select the
lowest RANGE switch position which will provide you
with a reading without causing the meter pointer to deflect
off-scale. If the maximum pointer deflection is below
one-half scale on the meter, set the V-fJ.-A slide switch to
the V-A/2 position and divide all readings by 2.
6
3. Do not check resistance (ohms) when voltage or current.is
present in the circuit.
4. Discharge a capacitor before measuring it.
5. Avoid placing the tester in a place where severe vibration is
encountered. Do not store it in an extremely hot or humid
location.
6. Remove the batteries before storing the tester for a long
period of time. Also rotate the RANGE switch from time to
time to clean the contacts.
7. To extend the life of the batteries, never leave the RANGE
switch in an OHMS setting when you are not in the process
of measuring reistance. It is best that you keep the RANGE
switch in the OFF position when the meter is not being used.
8. For all measu rements, plug the black test lead into the
e COM. jack. Plug the red test lead into the IJ) V-fJ.-A jack
except when measuring from 250 to 1,000 volts or check
batteries
9. You can see a reflection of the meter pointer in the mirror
arc. To avoid parallax errors in you r readings, look straight
down onto the meter scale. You are doing this perfectly if
the mi rror image of the pointer is covered by the actual
meter pointer, so ·that you do not see its reflection in the
mirror arc.
DC VOLTAGE MEASUREMENTS
Select the required DC voltage range or use the procedure in
#2 above under OPERATI NG SUGGESTIONS. Connect the
test leads across the circuit whose voltage is to be measured.
Observe polarity. Read DC voltage on the appropriate scale. Be
sure to take the setting of the V-fJ.-A slide switch into account.
The range is as indicated by the pointer knob on the RANGE
7

switch, when the V-D.-A slide switch is in the V-D.-A position.
The range is one-half that indicated by the pointer knob on the
RANGE switch, when the V-D.-A slide switch is in the V-A/2
position.
Select the required DC current range or use the procedure in
#2 above under OPERATING SUGGESTIONS. Connect the
test leads in series with the circuit to be measured. Observe
polarity. Read DC current on the appropriate scale. Be sure to
take the setting of the V-D. A slide switch into account, as
described in the DC VOLTAGE MEASUREMENTS section.
Should the ranges provided not be sufficient to measure current
in your circuit, the DC voltage ranges of your 5205 may be uti-
lized for this purpose. Measure the voltage across a resistor in
the circuit through which the current flows. If this is not pos-
sible, add a small resistor in series with the circuit. The added
resistor, if used, must be small enough so as not
to upset the circuit Measure the volt
this resistor. Calculate the current flowin
this resistor, using Ohm's Law. See th
in Figure 1. Here, it is assumed that
across a 1-ohm resistor. The curren
through the resistor is:
DC CURRENT MEASUREMENTS
E 2
1 =-- =-= 2 Amps
R 1
AC VOLTAGE MEASUREMENTS
T
2V
--.L
age across
D
g through
e example
2 volts is
t flowing
I
1D.
.
FIGURE 1
Select the required red AC voltage range or use the procedure in
#2 above under OPERA TI NG SUGGESTIONS. Connect the
8
9
test leads across the voltage to be measured .. Leads may be
connected in either direction. Read AC voltage on the appro-
priate scale. Be sure to take the setting of the V-D.-A slide
switch into account, as described in the DC VOLTAGE MEA-
SUREMENTS section.
)
j
AC CURRENT MEASUREMENTS
AC current cannot be measured directly on this instrument.'
However, if you need an AC current measurement, measure the
voltage across a resistor in the circuit or across a small resistor
wired in series with the circuit. Calculate the cu rrent flowing
through this resistor, using Ohm's Law. See the procedure
and example under DC CURRENT MEASUREMENTS.
RESISTANCE (OHMS) MEASUREMENTS
J
j
Set the RANGE switch to an OHMS range and the V-D.-A slide
switch to V-D.-A. Bring one test lead into contact with the
other and set the OHMS ADJ. control for a full scale reward
of the meter pointer. Separate the test leads and connect them
across the resistor to be measured. Read the resistance on the
OHMS scale. Use the appropriate multiplier as required for the
different resistance ranges.
BATTERY CHECK
Set the range selector switch to the BAT. CHECK position Put
red (f) probe into BAT. jack and black e probe into e COM
jack. When you test 1.5V AA or AAA size battery, set slide
switch to "1.5V AA" position. When you test 1.5V C or D
size battery, set slide switch to "1.5V C, D" position. When
vou test 9V transistor battery, set slide switch to "9V"
position. Connect red @ probe tip to ® terminal of the

battery and black e probe tip to e terminal of the battery
to be tested. Read position of the meter scale. If the reading is
in the red "BAD" zone, the battery should be replaced. If
the green "GOOD" zone the battery has considerable life.
lf reading is white ? zone you should consider making a
replacement, since very little power is left.
CAUTION: Always be sure that you identify the battery
polarity correctly before testing the battery.
DECEIBEL RATIO MEASUREMENTS
The ratio of two AC voltages can be expressed in terms of
dB. A standard has been adopted wh ich establ ishes one refer-
ence voltage as the 0 dB level. It is 0.774 volt rms (root mean
square). This assumes that 1 milliwatt is. developed across an
impedance of 600 ohms.
When using the 10 ACV range, read the dB scale if the V-n-A
slide switch is set to V-A/2. For dB measurements on the other
NOTE: Adjust voltage with variac before measuring capacitance
or inductance. Transformer voltage and shunt resistor require-
ments are discussed in the text. Do not change variac voltage
after setting has been made.
.---
0
TRANSFORMER
l+r-
mil
10 VAC 120r12.5K SEE
OR OHMS OR TEXT
250 VAC 310K OHMS
110V
120V VARIAC SHUNT
AC RESISTOR
FIGURE 2
-10-
AC ranges when the V·n-A slide switch is in the V·A/2 position,
read the same dB scale but now add 14 dB when set to the
50V range, 28 dB when set to the 250V range, and 40 dB when
set to the 1000V range. When the V·n·A slide switch is in the
V-n-A position, read the same dB scale on the meter but now
add 6 dB in the 10V range, 20 dB in the 50V range, 34 dB in
the 250V range, and 46 dB in the 1000V range.
INDUCTANCE MEASUREMENTS
1. Wire the circuit shown in Fig. 2 using a power transformer
and variable AC supply voltage. Connect a 12- or 12.5-K
ohm resistor across the test leads. (Note: The 12- or 12.5-
K ohm resistor is used across the test leads when measuring
inductance and high capacitance. A 31(}Kohms resistor is
used across the test leads when measuring low capac itance.)
Any inductance between 4 and 2000 Henrys can be
measured.
2. Set the RANGE switch to 10 ACV and the V-n·A slide
switch to V-n-A. Connect the test leads across the secondary
of the transformer, as shown in Figure 2. Starting at zero
UNKNOWN INDUCTANCE ~
OR CAPACITANCE
TRANSFORMER
~II rl
LORC
120r12.5KOHMS
~ ~ ~1~KOHMS
120V VARIAC SHUNT
AC FIGURE 3 RESISTOR
Circuit to measure inductance or capacitance
- 11-

volts, slowly increasethe AC voltage until you read 10volts.
Do not change this voltage setting until you havecompleted
the measurementsin step 3. .
3. Connect the. unknown inductor (drawn asa rectangular box
marked L OR C) asshown in Figure 3. Note the voltage on
the 10 volt scale. UseTABLE 1 to determine the inductance
in the circuit from the voltage read on the meter. You can
interpolate between values if the actual voltage read on the
meter is not indicated on the table.
TABLE 1. VOLTAGE TO INDUCTANCE CONVERSION
(4 HENRYS TO 2000 HENRYS)
INDUCT· RMSVOLTS INDUCT·
RMS VOLTS ANCE (H) ANCE (H)
9.88 43.14 80
9.83 52.81 90
9.75 6256 100
9.67 7216 120
9.57 8 1.86 140
9.47 91.63 160
9.35 10 1.45 180
7.99 20 1.31 200
6.63 30 0.88 300
5.52 40 0.64 400
4.67 50 0.53 500
4.04 60 0.27 1000
3.52 70 0.13 2000
HIGH CAPACITANCE MEASUREMENTS
(.005 TO 1 MFD)
1. Connect the circuit shown in Figure 2, using a 12- or 12.5-
Kohms resistor.
2. Set the RANGE switch to 10 ACV, and the V-n-A slide
switch to v·n-A. Connect the test leadsacrossthe secondary
of the transformer. Starting at zero.volts, slowly increasethe
12
-13 -
AC voltage until you read 10 volts. Do not change this
voltage setting until you have completed the measurements
in step 3.
3. Connect the capacitor (drawn asa rectangular box marked L
OR C) as shown in Figure 3. Note the voltage on the 10volt
scale. Use TABLE 2 to determine the capacitance in the
circuit from the voltage read on the meter. You can inter-
polate between values if the actual voltage read from the
meter is not indicated on the table.
TABLE 2. VOLTAGE TO CAPACITANCE CONVERSION
(.005 MFD TO 1 MFD)
RMS VOLTS CAPAC
1-
RMSVOLTS CAPACI-
TANCE (mtd) TANCE (rnfd)
.19 .005 4.67 .14
.32 .009 5.15 .16
.38 .01 5.61 .18
.73 .02 6.01
.2
1.11 .03 6.86 .25
1.49 .04 7.49 .3
1.85 .05 8.34 .4
2.21 .06 8.83 .5
2.55 .07 9.14 .6
2.87 .08 9.35 .7
3.20 .09 9.50 .8
3.52 .1 9.58 .9
4.12 .12 9.67 1
LOW CAPACITANCE MEASUREMENTS
(100 TO 50,000 PF)
1. Connect the circuit shown in Figure 2, using a 310,000-
ohm resistor.
2. Set the RANGE switch to 250 ACV and the V-n-A slide
switch to V-n-A. Connect the test leadsacrossthe secondary

of the transformer. Starting at zero volts, slowly increase
the AC voltage until you read 250 volts. Do not change
the voltage setting until you have completed the measure-
ments in step 3.
3. Connect the capacitor (drawn as a rsctanqular box marked
L OR C) asshown in Figure 3. To avoid an electric shock,
disconnect the variable supply from the power source while
working in the circuit, but do not changethe voltage setting.
Note the voltage on the 250 volt scale. Use TABLE 3 to
determine the capacitance 'in the circuit from the voltage
read on the meter. You can interpolate between values if
the actual voltage read from the meter is not indicated on
the table.
TABLE 3. VOLTAGE TO CAPACITANCE CONVERSION
(.0001 MFD TO .05 MFD) (100 PF-50,OOOPF)
RMSVOLTS CAPACI- RMSVOLTS CAPACI-
TANCE (pF) TANCE (pF)
2.25 100 59 2600
4.5 200 64 2800
6.75 300 68 3000
9.25 400 78. 3500
11.8 500 88 4000
14 600 97.5 4500
16 700 106 5000
18.1 800 112 5500
21 900 124 6000
23.3 1000 130 6500
27.7 1200 137 7000
32.7 1400 151 8000
37 1600 161 9000
42 1800 172 10K
46.2 2000 221 20K
51 2200 236 30K
55 2400 245 50K
- 14-
15
SCHEMATIC DIAGRAM
OFF
250 125
r iooo 500
50 25 Al 5M
0
C10 5R2 1M VR2
R3
187.5K 3K
V2.5 1.25
L
.25.125
R4
56.25K
r so, '] A20
5m 2.5m 15K
g 50m 25m
A soo- 250m A8 0.48
LSAT. CHEC
A9 CAL.
r 1000 500
A250 125
C50 25
V
L
10 5
A13
90 96
A14
950
A15
17.7K
A16
n o-----J 350K - 430K
~'I~-t--" A28
L... __ l__-'9'-'V'--.J A25 18.75M 900
A17 110K
i
I
R23 A27 0.84
665K
A24 9.5
o
eCOM
lQOOV DC