DIGITAL MULTIMETER KIT MODEL M-2666K WIDE RANGE DIGITAL MULTIMETER WITH CAPACITANCE AND TRANSISTOR TESTING FEATURES ELENCO® 150 Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 Website: www.elenco.com e-mail: elenco@elenco.com Assembly and Instruction Manual ELENCO Copyright © 2010 by ELENCO® All rights reserved. Revised 2010 ® REV-C No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.
INTRODUCTION SCHEMATIC DIAGRAM Assembly of your M-2666K Digital Multimeter Kit will prove to be an exciting project and give much satisfaction and personal achievement. If you have experience 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 and follow the easy step-by-step instructions. Remember, “An ounce of prevention is worth a pound of cure”.
A/D CONVERTER 5. SAFETY SYMBOLS ! 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. WARNING 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. CAUTION This CAUTION sign denotes a hazard.
VOLTAGE MEASUREMENT Figure 3 shows a simplified diagram of the voltage measurement function. The input divider resistors add up 10MΩ with each step being a division of 10. The divider output should be within –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.
3-3 Method of Measurement RESISTANCE MEASUREMENTS Figure 5 shows a simplified diagram of the resistance measurement function. (A) DC/AC Voltage Measurement (C) Resistance Measurement 1. Connect the red test lead to “VΩCAP” input jack and the black one to the “COM” jack. 1. Connect red test lead to the “VΩCAP” input jack and the black one to “COM”. 2. Turn the meter on by pressing the power switch. 2. Turn the meter on by pressing the power switch. 3.
a a f a b b f g c e b g c e d Transistor hFE a f b g d c e d BACKPLANE 28 LCD PHASE DRIVER 7 Segment Decode 7 Segment Decode TYPICAL SEGMENT OUTPUT V+ Test Condition 2mA 3V 2mA 3V Diode Test Measures forward resistance of a semiconductor junction in k Ohm at max. test current of 1mA. 7 Segment Decode 200 3. OPERATION 0.
ASSEMBLY AC Voltage Range 200mV 2V 20V 200V 750V Resolution 100μV 1mV 10mV 100mV 1V Accuracy +1.5% of rdg + 2dgt +1% of rdg + 2dgt +1% of rdg + 2dgt +1% of rdg + 2dgt +1.5% of rdg + 2dgt AC 750V maximum 50Hz - 400Hz Resistance Range 200Ω 2kΩ 20kΩ 200kΩ 2MΩ 20MΩ Resolution 0.1Ω 1Ω 10Ω 100Ω 1kΩ 10kΩ Accuracy +1% of rdg + 2dgt +0.8% of rdg + 2dgt +0.8% of rdg + 2dgt +0.8% of rdg + 2dgt +0.8% of rdg + 3dgt +2.0% of rdg + 4dgt Test Current Approximately 1.
CONSTRUCTION 1. FEATURES Introduction The most important factor in assembling your M-2666K Digital Multimeter Kit is good soldering techniques. Using the proper soldering iron is of prime importance. A small pencil type soldering iron of 25 - 40 watts is recommended. The tip of the iron must be kept clean at all times and well tinned. Solder • Turn off iron when not in use or reduce temperature setting when using a soldering station.
REINSTALLATION OF THE RANGE SELECTOR KNOB If you removed the rotary selector knob for troubleshooting, then follow the instructions below to reinstall it. Slide Contact Place the PC board over the range selector knob and fasten the knob to the PC board with a M2.3 x 8 screw. CAUTION: Do not over-tighten the screw. The knob should be snug, but not loose. Turn back the M2.3 x 8 screw 1/2 turn. Slip the two shims under the knob (see Figure W). If they do not slip in, turn back the screw another 1/4 turn.
RESISTOR READING EXERCISE Before starting assembly of your digital multimeter project, you should be thoroughly familiar with the 5 band color code system. Many of the resistor values will be identified by color bands and it is easy to mistake their value if you read the colors incorrectly or read the value from the wrong end. Do the following exercise in resistor values. Place your answer in the box beneath the resistor. Answers are on the bottom of this page.
TROUBLESHOOTING GUIDE If the meter is not working, perform the U1 (7106) Voltage Test first. This test is to verify that the IC and Reference Voltage are operational. Then perform SECTION A the tests that pertain to the Function that is not working on your meter. Meter Display Circuit PARTS LIST - SECTION A U1 (7106) Voltage Test Voltage/OHM Section 1. Measure the voltage across pin 8 and pin 34 on U1 (7106) for 9V. 1.
ASSEMBLE THE FOLLOWING COMPONENTS TO THE PC BOARD FINAL ASSEMBLY (continued) In all of the following steps the components must be installed either on the top or bottom legend sides of the PC board as indicated. The board is turned to solder the component leads on the opposite side (installed on Bottom, soldered on Top, installed on Top, soldered on Bottom). r Feed the battery snap wires through the slot on the top case as shown in Figure U.
ASSEMBLE THE LCD r Assemble the LCD into the housing with the parts shown in Figure F. Note the top of the house is curved. Figure T Top Case Testing Procedure The LCD housing will not be screwed to the PC board for this test. Align the LCD housing holes with those in the PC Board and hold in place. You can also use a rubber band to hold the housing. You will need to apply pressure so the zebra makes contact to the copper pads.
SECTION B SECTION F DC Voltage & Current Circuit Final Assembly PARTS LIST - SECTION B PARTS LIST - SECTION F RESISTORS Qty. r1 r1 r1 r1 r1 r1 r1 r2 r1 r1 r1 r1 r1 r4 r1 Symbol R23 R22 R21 R20 R18 R32 R31 R17, R19 R33 R16 R30 R15 R14 R10-R13 VR1 Description .01Ω 0.99Ω 0.5% 1/4W 9Ω 0.5% 1/4W 90Ω 0.5% 1/4W 100Ω 0.5% 1/4W 390Ω 1% 1/4W 900Ω 1% 1/4W 900Ω 0.5% 1/4W 5.6kΩ 5% 1/4W 9kΩ 0.5% 1/4W 13kΩ 1% 1/4W 90kΩ 0.5% 1/4W 900kΩ 0.5% 1/4W 2.25MΩ 0.
ASSEMBLE THE FOLLOWING COMPONENTS TO THE PC BOARD In all of the following steps the components must be installed either on the top or bottom legend sides of the PC board as indicated. The board is turned to solder the component leads on the opposite side (installed on Bottom, soldered on Top, installed on Top, soldered on Bottom). Figure H Figure I Stand diode on end. Mount with band as shown on the top legend. Band White marking on PC board Stand resistor on end as shown.
r Insert the four input sockets into the PC board holes and then solder the sockets in place. Apply enough heat to allow the solder to flow around the input sockets (see Figure J). r Attach the LCD to the PC board using the two 2.5 x 8mm screws. Use the two top mounting hole and lightly tighten the screws. The screws will be removed to assemble the next section.
r Attach the LCD to the PC board using the two 2.5 x 8mm screws. Use the top-mounting hole and lightly tighten the screws. The screws will be removed to assemble the next section. with another meter of known accuracy. If the tests are not working, check the solder of the PTC. Buzzer - Set the selector knob to the Buzzer ( ) position. Short the red and black leads and the buzzer should sound. If the buzzer does not sound, check components R51-R58, PTC, C16, C17, and the solder connections to the buzzer.
ASSEMBLE THE FOLLOWING COMPONENTS TO THE PC BOARD R39 - 6.8kΩ 5% 1/4W Res. (blue-gray-red-gold) (see Figure I) Figure M Insert the IC socket into the PC board with the notch in the same direction marked on the top legend. Solder the IC socket into place. Insert the IC into the socket with the notch in the same direction as the notch on the socket. Socket Top Legend Side Resistance & Buzzer Circuit C11 - 10μF Lytic Capacitor (see Figure B) PARTS LIST - SECTION D VR2 - 200Ω Pot (201) Qty.
ASSEMBLE THE FOLLOWING COMPONENTS TO THE PC BOARD R39 - 6.8kΩ 5% 1/4W Res. (blue-gray-red-gold) (see Figure I) Figure M Insert the IC socket into the PC board with the notch in the same direction marked on the top legend. Solder the IC socket into place. Insert the IC into the socket with the notch in the same direction as the notch on the socket. Socket Top Legend Side Resistance & Buzzer Circuit C11 - 10μF Lytic Capacitor (see Figure B) PARTS LIST - SECTION D VR2 - 200Ω Pot (201) Qty.
r Attach the LCD to the PC board using the two 2.5 x 8mm screws. Use the top-mounting hole and lightly tighten the screws. The screws will be removed to assemble the next section. with another meter of known accuracy. If the tests are not working, check the solder of the PTC. Buzzer - Set the selector knob to the Buzzer ( ) position. Short the red and black leads and the buzzer should sound. If the buzzer does not sound, check components R51-R58, PTC, C16, C17, and the solder connections to the buzzer.
r Insert the four input sockets into the PC board holes and then solder the sockets in place. Apply enough heat to allow the solder to flow around the input sockets (see Figure J). r Attach the LCD to the PC board using the two 2.5 x 8mm screws. Use the two top mounting hole and lightly tighten the screws. The screws will be removed to assemble the next section.
ASSEMBLE THE FOLLOWING COMPONENTS TO THE PC BOARD In all of the following steps the components must be installed either on the top or bottom legend sides of the PC board as indicated. The board is turned to solder the component leads on the opposite side (installed on Bottom, soldered on Top, installed on Top, soldered on Bottom). Figure H Figure I Stand diode on end. Mount with band as shown on the top legend. Band White marking on PC board Stand resistor on end as shown.
SECTION B SECTION F DC Voltage & Current Circuit Final Assembly PARTS LIST - SECTION B PARTS LIST - SECTION F RESISTORS Qty. r1 r1 r1 r1 r1 r1 r1 r2 r1 r1 r1 r1 r1 r4 r1 Symbol R23 R22 R21 R20 R18 R32 R31 R17, R19 R33 R16 R30 R15 R14 R10-R13 VR1 Description .01Ω 0.99Ω 0.5% 1/4W 9Ω 0.5% 1/4W 90Ω 0.5% 1/4W 100Ω 0.5% 1/4W 390Ω 1% 1/4W 900Ω 1% 1/4W 900Ω 0.5% 1/4W 5.6kΩ 5% 1/4W 9kΩ 0.5% 1/4W 13kΩ 1% 1/4W 90kΩ 0.5% 1/4W 900kΩ 0.5% 1/4W 2.25MΩ 0.
ASSEMBLE THE LCD r Assemble the LCD into the housing with the parts shown in Figure F. Note the top of the house is curved. Figure T Top Case Testing Procedure The LCD housing will not be screwed to the PC board for this test. Align the LCD housing holes with those in the PC Board and hold in place. You can also use a rubber band to hold the housing. You will need to apply pressure so the zebra makes contact to the copper pads.
ASSEMBLE THE FOLLOWING COMPONENTS TO THE PC BOARD FINAL ASSEMBLY (continued) In all of the following steps the components must be installed either on the top or bottom legend sides of the PC board as indicated. The board is turned to solder the component leads on the opposite side (installed on Bottom, soldered on Top, installed on Top, soldered on Bottom). r Feed the battery snap wires through the slot on the top case as shown in Figure U.
TROUBLESHOOTING GUIDE If the meter is not working, perform the U1 (7106) Voltage Test first. This test is to verify that the IC and Reference Voltage are operational. Then perform SECTION A the tests that pertain to the Function that is not working on your meter. Meter Display Circuit PARTS LIST - SECTION A U1 (7106) Voltage Test Voltage/OHM Section 1. Measure the voltage across pin 8 and pin 34 on U1 (7106) for 9V. 1.
RESISTOR READING EXERCISE Before starting assembly of your digital multimeter project, you should be thoroughly familiar with the 5 band color code system. Many of the resistor values will be identified by color bands and it is easy to mistake their value if you read the colors incorrectly or read the value from the wrong end. Do the following exercise in resistor values. Place your answer in the box beneath the resistor. Answers are on the bottom of this page.
REINSTALLATION OF THE RANGE SELECTOR KNOB If you removed the rotary selector knob for troubleshooting, then follow the instructions below to reinstall it. Slide Contact Place the PC board over the range selector knob and fasten the knob to the PC board with a M2.3 x 8 screw. CAUTION: Do not over-tighten the screw. The knob should be snug, but not loose. Turn back the M2.3 x 8 screw 1/2 turn. Slip the two shims under the knob (see Figure W). If they do not slip in, turn back the screw another 1/4 turn.
CONSTRUCTION 1. FEATURES Introduction The most important factor in assembling your M-2666K Digital Multimeter Kit is good soldering techniques. Using the proper soldering iron is of prime importance. A small pencil type soldering iron of 25 - 40 watts is recommended. The tip of the iron must be kept clean at all times and well tinned. Solder • Turn off iron when not in use or reduce temperature setting when using a soldering station.
ASSEMBLY AC Voltage Range 200mV 2V 20V 200V 750V Resolution 100μV 1mV 10mV 100mV 1V Accuracy +1.5% of rdg + 2dgt +1% of rdg + 2dgt +1% of rdg + 2dgt +1% of rdg + 2dgt +1.5% of rdg + 2dgt AC 750V maximum 50Hz - 400Hz Resistance Range 200Ω 2kΩ 20kΩ 200kΩ 2MΩ 20MΩ Resolution 0.1Ω 1Ω 10Ω 100Ω 1kΩ 10kΩ Accuracy +1% of rdg + 2dgt +0.8% of rdg + 2dgt +0.8% of rdg + 2dgt +0.8% of rdg + 2dgt +0.8% of rdg + 3dgt +2.0% of rdg + 4dgt Test Current Approximately 1.
a a f a b b f g c e b g c e d Transistor hFE a f b g d c e d BACKPLANE 28 LCD PHASE DRIVER 7 Segment Decode 7 Segment Decode TYPICAL SEGMENT OUTPUT V+ Test Condition 2mA 3V 2mA 3V Diode Test Measures forward resistance of a semiconductor junction in k Ohm at max. test current of 1mA. 7 Segment Decode 200 3. OPERATION 0.
3-3 Method of Measurement RESISTANCE MEASUREMENTS Figure 5 shows a simplified diagram of the resistance measurement function. (A) DC/AC Voltage Measurement (C) Resistance Measurement 1. Connect the red test lead to “VΩCAP” input jack and the black one to the “COM” jack. 1. Connect red test lead to the “VΩCAP” input jack and the black one to “COM”. 2. Turn the meter on by pressing the power switch. 2. Turn the meter on by pressing the power switch. 3.
VOLTAGE MEASUREMENT Figure 3 shows a simplified diagram of the voltage measurement function. The input divider resistors add up 10MΩ with each step being a division of 10. The divider output should be within –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.
A/D CONVERTER 5. SAFETY SYMBOLS ! 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. WARNING 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. CAUTION This CAUTION sign denotes a hazard.
INTRODUCTION SCHEMATIC DIAGRAM Assembly of your M-2666K Digital Multimeter Kit will prove to be an exciting project and give much satisfaction and personal achievement. If you have experience 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 and follow the easy step-by-step instructions. Remember, “An ounce of prevention is worth a pound of cure”.
DIGITAL MULTIMETER KIT MODEL M-2666K WIDE RANGE DIGITAL MULTIMETER WITH CAPACITANCE AND TRANSISTOR TESTING FEATURES ELENCO® 150 Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 Website: www.elenco.com e-mail: elenco@elenco.com Assembly and Instruction Manual ELENCO Copyright © 2010 by ELENCO® All rights reserved. Revised 2010 ® REV-C No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.
