background image

r

Put the ball bearings into two opposite indents in
the case top as shown in Figure M.

r

Place the six slide contacts on the selector knobs
as shown.

r

Place the selector knob into the case top so that
the springs fit over the ball bearings as shown.

r

Place the PC board over the selector knob. Be
sure that the 8-pin socket slides into its hole. Then
fasten the PC board with five 6mm screws as
shown.

r

Insert the 200mA, 250V fuse into the fuse clips.

r

Peel the backing off of the front label and place it
on the case top.

r

Connect a 9V battery to the battery snap.

-7-

Figure M

PC board

6mm Screws

Slide

contacts

Rib

Close-up view

Ball bearings

Battery compartment

Case top

Selector knob

Содержание M-1008K

Страница 1: ... All rights reserved 753014 No part of this book shall be reproduced by any means electronic photocopying or otherwise without written permission from the publisher DIGITAL MULTIMETER KIT MODEL M 1008K Assembly and Instruction Manual ...

Страница 2: ... 5 1 4W orange green red orange green 163550 r 1 R6 548kΩ 0 5 1 4W green yellow gray orange green 165450 r 1 R15 24 30 31 32 1MΩ 1 1 4W brown black black yellow brown 171030 Resistors tolerance may be lower than listed These parts are not mounted on card r 1 R13 0 01Ω Shunt wire 100165 r 1 VR1 200Ω 201 Potentiometer 191300 CAPACITORS Qty Symbol Value Description Part r 1 C6 100pF 101 Disc 221017 r...

Страница 3: ...to signify a decimal point as in 3R3 3 3 10μF 16V 103K 100V The letter M indicates a tolerance of 20 The letter K indicates a tolerance of 10 The letter J indicates a tolerance of 5 Maximum working voltage The value is 10 x 1 000 10 000pF or 01μF 100V Electrolytic capacitors have a positive and a negative electrode The negative lead is indicated on the packaging by a stripe with minus signs and po...

Страница 4: ...ee solder for health reasons This kit contains lead free solder which contains 99 3 tin 0 7 copper and has a rosin flux core Lead free solder is different from lead solder It has a higher melting point about 440O F compared to about 360O F for lead solder so you need higher temperature for the solder to flow properly Recommended tip temperature is 700O F 800O F higher temperatures improve solder f...

Страница 5: ...00pF 101 Discap R17 100kΩ 1 1 4W Resistor brown black black orange brown see Figure A R23 470Ω 1 1 4W Resistor yellow violet black black brown see Figure A R28 220kΩ 1 1 4W Resistor red red black orange brown see Figure A Q2 2SA9015 Transistor see Figure C C7 220pF 221 Discap R29 220kΩ 1 1 4W Resistor red red black orange brown see Figure A R24 1MΩ 1 1 4W Resistor brown black black yellow brown se...

Страница 6: ...black white white silver green see Figure A Q1 2SA9013 Transistor see Figure C R9 1 5kΩ PTC Resistor R6 548kΩ 0 5 1 4W Resistor green yellow gray orange green see Figure A R21 220kΩ 1 1 4W Resistor red red black orange brown see Figure A r Insert the narrow end of the three input sockets into the PC board from the top legend as shown in Figure F Solder the sockets to the PC board on the top legend...

Страница 7: ... to the PC board as shown in Figure H r Solder the red wire to the BZ pad and black wire to the BZ pad as shown in Figure H r Remove the clear protective film from the front of the LCD as shown in Figure I Note DO NOT remove the white backing on the other side of the LCD r Insert the LCD into the frame the tab on the LCD must be in the same direction shown in Figure J r Insert the zebra frame as s...

Страница 8: ...as shown r Place the PC board over the selector knob Be sure that the 8 pin socket slides into its hole Then fasten the PC board with five 6mm screws as shown r Insert the 200mA 250V fuse into the fuse clips r Peel the backing off of the front label and place it on the case top r Connect a 9V battery to the battery snap 7 Figure M PC board 6mm Screws Slide contacts Rib Close up view Ball bearings ...

Страница 9: ... switch to the 20V position and connect the test leads to the VΩmA and COM sockets Using another meter of known accuracy measure a DC voltage of less than 20 volts such as a 9V battery Calibrate the kit meter by measuring the same voltage and adjusting VR1 until the kit meter reads the same as the accurate meter do not use the kit meter to measure its own battery When the two meters agree the kit ...

Страница 10: ...ltage should be about 120VAC Compare the reading to a meter of known accuracy If either if the above tests fail a Check the values and the soldering of resistors D1 R1 6 and R19 b Check that diode D1 is mounted as shown in the assembly instructions Range Switch RA Current approx 2mA 10kΩ 900μA 20mA 1kΩ 9mA 200mA 470Ω 19mA DC VOLTS TEST Figure O 1kΩ 10A DC VΩmA COM 100Ω 9V 123 Figure P 10kΩ 10A DC ...

Страница 11: ...ld read about 700mV Power diodes and the base to emitter junction of power transistors may read less If any of these tests fail a Check the values and the soldering of resistors PTC R1 6 R9 and R16 hFE TEST 1 Set the range switch to hFE and insert a small transistor into the appropriate NPN or PNP holes in the transistor socket 2 Read the hFE of the transistor The hFE of transistors varies over a ...

Страница 12: ...onverter can be divided into three consecutive time periods autozero AZ integrate INTEG and read A counter determines the length of the time periods The integrate period is fixed at 1 000 clock pulses The read period is a variable time that is proportional to the unknown input voltage It can vary from zero counts for zero input voltage to 2 000 counts for a full scale input voltage The autozero pe...

Страница 13: ...d switch closes This applies a known reference voltage to the input to the A D converter The polarity of this voltage is automatically selected to be opposite that of the unknown input voltage thus causing the INTEG capacitor to discharge at a fixed rate slope This rate is determined by the known reference voltage When the charge is equal to the initial starting point autozero level the read perio...

Страница 14: ...verters One inverter shown for clarity 7 6 4 OSC 1 OSC 2 OSC 3 DIGITAL SECTION ANALOG SECTION of 7106 CREF RINT CAZ CINT INT CREF REF HI REF LO CREF BUFFER V 35 42 44 43 41 36 37 1 AUTO ZERO A Z Z1 A Z Z1 A Z DE DE DE DE IN HI COMMON IN LO 40 39 INT 10μA V 38 INT 2 8V A Z DE Z1 34 V Z1 6 2V A Z COMPARATOR ZERO CROSSING DETECTOR POLARITY FLIP FLOP TO DIGITAL SECTION INTEGRATOR REF Flying Capacitor ...

Страница 15: ...ts Common Figure 5 Simplified AC Voltage Measurement Diagram Volts Common 7106 100mV REF Low Pass Filter Rectifier Low Pass Filter Scaler 600V 200V 100Ω 900Ω Figure 6 Simplified DC Amps Measurement Diagram Common 10A A 9Ω 99Ω 01Ω 20mA 2mA 200μA 200mA 10A 900Ω 100Ω 2mA 200μA 20mA 200mA 10A 7106 100mV REF Low Pass Filter Figure 7 Simplified Resistance Measurement Diagram Ω 900kΩ Test Resistor 100Ω 9...

Страница 16: ... PROTECTION 200mA 250V fuse μA mA input only 10A not fused 15 seconds only AC VOLTAGE RANGE RESOLUTION ACCURACY 200V 100mV 2 rdg 10d 600V 1V 2 rdg 10d MAXIMUM ALLOWABLE INPUT 600VDC or rms AC FREQUENCY 45 450Hz RESISTANCE RANGE RESOLUTION ACCURACY 200Ω 0 1Ω 1 rdg 10d 2000Ω 1Ω 1 rdg 10d 20kΩ 10Ω 1 rdg 10d 200kΩ 100Ω 1 rdg 10d 2000kΩ 1kΩ 1 rdg 4d MAXIMUM OPEN CIRCUIT VOLTAGE 3 2V MAXIMUM ALLOWABLE I...

Страница 17: ...lead to the 10ADC terminal 3 Set the range switch to the 10A position 4 Open the circuit to be measured and connect the leads in series with the load to be measured 5 Read the display If the display read less than 200mA follow the low current procedure below 6 Turn off all of the power to the circuit being tested and discharge all of the capacitors before disconnecting the test leads LOW CURRENTS ...

Страница 18: ...the A D converter is to r A convert digital to analog r B divide the analog signal by 2 r C convert analog to digital r D convert AC to DC 2 The divider used for DC voltage measurements is a r A divide by 20 r B capacitance divider r C divide by 5 r D resistor divider 3 When the AC voltage is measured it is first r A divided by 2 r B rectified r C divided by 100 r D sent to a high pass filter 4 Wh...

Страница 19: ... 18 Answers to Quiz 1 C 2 D 3 B 4 A 5 D 6 A 7 B 8 C 9 B 10 B SCHEMATIC DIAGRAM ...

Страница 20: ...ELENCO 150 Carpenter Avenue Wheeling IL 60090 847 541 3800 Website www elenco com e mail elenco elenco com 050712 ...

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