background image

-3-

VOLTAGE MEASUREMENT

Figure 3  Simplified Voltage Measurement Diagram

Figure 4  Simplified Current Measurement Diagram

200mV

Volts

9M

900k

90k

9k

1k

Common

1kV

200V

20V

2V

AC to DC

Converter

AC

DC

Low Pass

Filter

100mV

Ref

7106R

200

µ

A

900

2mA

20mA

200mA

20A

100

9

1

Shunt

.01

COM

20A

20A

200mA

20mA

200

µ

A

2mA

AC - DC

Converter

AC

DC

Low

Pass
Filter

100mV

Ref

7106R

Figure 3 shows a simplified diagram of the voltage
measurement function.
The input divider resistors add up 10M

with each

step being a division of 10.

The divider output

should be withing –0.199 to +0.199V or the overload

indicator will function. If the AC function is selected,
the divider output is AC coupled to a full wave
rectifier and the DC output is calibrated to equal the
rms level of the AC input.

Figure 4 shows a simplified diagram of the current
measurement positions.
Internal shunt resistors convert the current to
between –0.199 to +0.199V which is then

processed in the 7106 IC to light the appropriate
LCD segments. If the current is AC in nature, the
AC converter changes it to the equivalent DC value.

CURRENT MEASUREMENT

4. OPERATION MAINTENANCE

4-1 Battery and Fuse Replacement

-32-

This marking adjacent to another marking or a
terminal operating device indicates that the
operator must refer to an explanation in the
operating instructions to avoid damage to the
equipment and/or to avoid personal injury.

This WARNING sign denotes a hazard.

It calls

attention to a procedure, practice or the like, which
if not correctly performed or adhered to, could result
in personal injury.

This CAUTION sign denotes a hazard.

It calls

attention to a procedure, practice or the like, which
if not correctly adhered to, could result in damage to
or destruction of part or all of the instrument.

This marking advises the user that the terminal(s)
so marked must not be connected to a circuit point
at which the voltage, with respect to earth ground,
exceeds (in this case) 500 volts.

This symbol adjacent to one or more terminals
identifies them as being associated with ranges that
may in normal use be subjected to particularly
hazardous voltages.

For maximum safety, the

instrument and its test leads should not be handled
when these terminals are energized.

5. SAFETY SYMBOLS

CAUTION

BEFORE ATTEMPTING BATTERY REMOVAL OR
REPLACEMENT, DISCONNECT THE TEST
LEADS FROM ANY ENERGIZED CIRCUITS TO
AVOID SHOCK HAZARD.

The fuse rarely needs replacement and blow almost
always as a result of operator error. To replace the
battery and fuse (2A/250V), remove the two screws
in the bottom of the case. Simply remove the old
battery or fuse and replace with a new one.

Be sure to observe the polarity when replacing the
battery.

4-2 Calibration Procedure

It is normally not necessary to recalibrate for long
intervals.

If needed, adjustment should be done

with highly accurate standards (setter than 0.1%
accuracy).

Remove the two phillips head screws.

Carefully

remove the plastic back cover. With the instrument
operating and set to the 200mV DC range (20

µ

F

capacitance range), apply 190mV DC (10

µ

F) from

an accurate source.

With a small screwdriver

inserted into the semi-fixed resistor VR1 (VR2:
Capacitance), carefully turn the variable resistor
until the reading reads 190mV (10

µ

F).

NOTE:

Be sure to proceed basic calibration by DC

range first prior to capacitance.

WARNING

CAUTION

500V max.

!

Summary of Contents for M-2665K

Page 1: ...ttp www elenco com e mail elenco elenco com DIGITAL MULTIMETER KIT MODEL M 2665K WIDE RANGE DIGITAL MULTIMETER WITH CAPACITANCE AND TRANSISTOR TESTING FEATURES Assembly and Instruction Manual Elenco E...

Page 2: ...xperience in soldering and wiring technique you should have no problems For the beginner care must be given to identifying the proper components and in good soldering habits Above all take your time a...

Page 3: ...scharge as fixed rate slope When the charge is equal to the initial starting point autozero level the read period is ended Since the discharge slope is fixed during the read period the time required i...

Page 4: ...is CAUTION sign denotes a hazard It calls attention to a procedure practice or the like which if not correctly adhered to could result in damage to or destruction of part or all of the instrument This...

Page 5: ...ck 3 Set the range selector knob to the position 4 If the semiconductor junction being measured is connected to the circuit turn off the power to the circuit being tested and discharge all of the capa...

Page 6: ...leads to the device or circuit being measured 5 Turn on the power to the device or circuit being measured The voltage value will appear on the digital display along with the voltage polarity 6 Turn o...

Page 7: ...es 2 Avoid any excessive accumulation of resin build up whenever you solder a connection 3 Take your time assembling the circuit board Work at a slow pace Remember that accuracy is far more important...

Page 8: ...remove the solder and the iron and let the connection cool The solder should have flowed smoothly and not lump around the wire lead 4 Here is what a good solder connection looks like 2 Insufficient s...

Page 9: ...0 1 2 3 4 5 8 9 Multiply By 1 10 100 1k 10k 100k 01 0 1 Multiplier Note The letter R may be used at times to signify a decimal point as in 3R3 3 3 10 F 16V 103K 100V The letter M indicates a tolerance...

Page 10: ...crew 1 2 turn Slip the two shims under the knob see Figure L If they do not slip in turn back the screw another 1 4 turn Tighten the screw just enough so that the shims can be pulled out You should no...

Page 11: ...0000 1 PC Board 516000A 1 Solder Roll 551135 1 Battery Snap BAT 590098 1 Battery 590009 1 LCD Window Plate 621002A 1 Range Selector Knob 622003 1 Bushing 624004 Qty Description Part 1 LCD Stopper 6290...

Page 12: ...N5232 Diode see Figure C BAT Battery Snap Insert both wires through the hole and mount the red wire to the hole and the black wire to the hole Solder the wires from the top legend side Notch Notch 24...

Page 13: ...Range Selector Knob LCD Window Plate NOTE If the range selector switch becomes hard to turn then loosen the M2 3 x 8 screw slightly 23 Testing Procedure SECTION C AC voltage and current circuit Measu...

Page 14: ...R1 9M 5 1 2W white black black yellow green 179051 1 VR1 200 220 Potentiometer 191320 Note Some resistors may not have a color coding but they will have the value imprinted on them Note Resistor toler...

Page 15: ...es orange white red red brown see Figure E C1 22 F Lytic Capacitor see Figure F R27 2k 1 1 4W Res red blk blk brown brown see Figure E R28 1 3k 1 1 4W Res brn orange blk brn brn see Figure E R46 5 6k...

Page 16: ...of 1 10 amps If the tests are not working check for cold solder joints and part values Turn the meter off and remove the battery and test leads DO NOT PROCEED TO SECTION C WITHOUT YOUR INSTRUCTOR S AP...

Page 17: ...der the socket to the PC board Insert the IC into the socket with the notch as shown below Socket Notch C8 Figure I Mount the capacitor with the negative lead in the negative hole and the positive lea...

Page 18: ...own brown brown 141930 1 R40 4 12k 1 1 4W yellow brown red brown brown 144130 1 R9 9k 1 1 4W white black black brown brown 149030 1 R38 10k 1 1 4W brown black black red brown 151030 1 R43 11k 1 1 4W b...

Reviews: