Elenco 23 Range 20k/V VOM in Kit Form User Manual

ANALOG MULTIMETER KITMODEL M-1250KCopyright © 2007, 2000 by Elenco®Electronics, Inc. All rights reserved. Revised 2007 REV-H 753070N

-9-INSTALL BATTERY CLIPSInstall the PC board into the case (see Figure O).Align the buzzer holder over the two posts and press it down in place (see F

-10-CALIBRATIONBatteriesInstall the following parts:1. Install the 9V and the two 1.5V (AA) batteries as shown in Figure 1. Be sure to observe the po

-11-INSTALL BACK COVER AND 0Ω ADJ KNOBInstall the bottom case and mount into place with an M4 x 10 screw as shown in Figure Q.Place the 0Ω ADJ knob on

-12-TROUBLESHOOTING CHARTThis chart lists the condition and possible causes of several malfunctions. If a particular part is mentioned asa possible c

-13-OPERATING AND TESTING THE MULTIMETERCAUTION: When measuring an unknown voltage or current, always start with the range switch set to thehighest sc

-14-AC Voltage TestIn reading AC voltage, it is necessary to obtain a known source of AC. A 12 volt transformer is preferred. If oneis not available,

-15-THEORY OF OPERATIONIntroductionYour multimeter is of professional quality using 1% precision resistors throughout the design. The accuracy atfull

-16-DC Current MeasurementFigure 6 shows a simplified diagram of the DC current measuring circuit. Here the resistors are placed acrossthe meter to s

hFE MeasurementFigure 8 shows a simplified diagram of the hFE measuring circuit for PNP transistor. Here the range switch is inthe X10 ohms position

SCHEMATIC DIAGRAM M-1250K-18-Pin-out2SC18152SA1015E C B

PARTS LISTIf you are a student, and any parts are missing or damaged, please see instructor or bookstore.If you purchased this kit from a distributor,

Elenco®Electronics, Inc.150 Carpenter AvenueWheeling, IL 60090(847) 541-3800Web site: www.elenco.come-mail: [email protected]

-2-* These parts are part of the main rotary switch assembly. This may come preassembled by the factory.SEMICONDUCTORSQty. Symbol Value Description P

IntroductionAssembly of your M-1250 Analog Multimeter Kit will prove to be an excitingproject and give you much satisfaction and personal achievement.

-4-ASSEMBLE COMPONENTS TO THE PC BOARDAfter each step, put a check in the box located next to the step that you have completed.Place the PC board on a

-5-C3 - .047μF Discap (473)R29 - 820kΩ 1% 1/4W Resistor(gray-red-black-orange-brown)Q1 - C1815 Transistor(see Figure C)R30 - 260kΩ 1% 1/4W Resistor(re

-6-ASSEMBLE COMPONENTS TO THE PC BOARDAfter each step, put a check in the box located next to the step that you have completed.R28 - 3MΩ 1% 1/2W Resis

ASSEMBLE THE BUZZERTin the buzzer in the three locations shown in Figure Ka.Tin both ends of the 3.5” red, white, and green wires as shown in Figure K

SOLDER METER MOVEMENT WIRES TO PC BOARDTin the ends of the meter wires. Solder the red meter wire to M+ and the black wire to M– on the foil side oft