LOGIC PULSER KIT MODEL LP-425K Assembly and Instruction Manual Elenco Electronics, Inc. Copyright © 1995 Elenco Electronics, Inc.
PARTS LIST If you are a student, and any parts are missing or damaged, please see instructor or bookstore. If you purchased this kit from a distributor, catalog, etc., please contact Elenco Electronics (address/phone/email is at the back of this manual) for additional assistance, if needed. RESISTORS Qty. 2 1 2 3 1 4 1 2 1 Symbol R1, R16 R17 R11, R13 R12, R14, R15 R8 R2, R7, R9, R10 R5 R3, R6 R4 Description 100W 5% 1/4W 470W 5% 1/4W 2kW 5% 1/4W 20kW 5% 1/4W 68kW 5% 1/4W 100kW 5% 1/4W 1MW 5% 1/4W 1.
IDENTIFYING RESISTOR VALUES Use the following information as a guide in properly identifying the value of resistors. BAND 1 1st Digit Bands 1 2 Multiplier Tolerance Color Black Brown Red Orange Yellow Green Blue Violet Gray White Digit 0 1 2 3 4 5 6 7 8 9 Multiplier BAND 2 2nd Digit Color Black Brown Red Orange Yellow Green Blue Violet Gray White Resistance Tolerance Color Multiplier Black 1 Brown 10 Red 100 Orange 1,000 Yellow 10,000 Green 100,000 Blue 1,000,000 Silver 0.01 Gold 0.
CONSTRUCTION Introduction The most important factor in assembling your LP-425K Logic Pulser 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. Safety Procedures • Wear eye protection when soldering. • Locate soldering iron in an area where you do not have to go around it or reach over it. • Do not hold solder in your mouth.
ASSEMBLE COMPONENTS TO THE PC BOARD Refer to the top legend on the PC board, install and solder the following resistors. All are 1/4 watt, 5% tolerance. (Resistors R11 and R12 install vertical).
ASSEMBLE COMPONENTS TO THE PC BOARD Refer to the top legend on the PC board, install and solder the following diodes and capacitors.
ASSEMBLE COMPONENTS TO THE PC BOARD Refer to the top legend on the PC board, install and solder the following components. Q3 - 2N3906 Transistor (see Figure 7) D6 - LED (see Figure 8) Q4 - 2N3904 Transistor (see Figure 7) Q1 - 2N3904 Transistor (see Figure 7) Q5 - 2N3904 Transistor (see Figure 7) U1 - 14-Pin IC Socket U1 - 74C04 IC or 4069 (see Figure 5) Q2 - 2N3906 Transistor (see Figure 7) SW1 - Switch (see Figure 6) P1, P2, P3 - Pins Do not install the pins to the PC board.
Install the power cord as shown in Figure 9. Pull the power cord wires apart about 2 inches on one end. Strip the insulation off of both wires to expose 1/4” of bare wire. Note that one wire is ribbed on the edge. Solder the red alligator clip to the ribbed wire. Solder the black clip to the smooth wire. On the other side of the power cord, pull the wires apart 1/2”. Strip 1/4” of insulation off of both wires. Make a knot to serve as a strain relief (about 1 inch from the end).
TESTING YOUR LOGIC PULSER Checking out your Logic Pulser for proper operation is fairly easy. All that is needed is a 9V battery or other DC power source (5-10V). Connect the red alligator clip to the positive terminal of the battery and the black clip to the negative terminal. If you have an oscilloscope, connect it to the Square (SQ) Pin and observe the waveforms shown in Figure 12 for pulse repetition rate switch settings of 400PPS and .5PPS. The times shown are approximate.
SCHEMATIC DIAGRAM Note: All resistors are 5% 1/4W IC 74C04 or 4069 Schematic Diagram LP-425 -9-
QUIZ 1) The LP-425 Logic Pulser can produce a _______ microsecond pulse at 100mA. A. 30 B. 15 C. 10 D. 20 6) The LP-425 Logic Pulser is a very handy device for inspecting and repairing __________________. A. motor circuits. B. logic circuits. C. lighting circuits. D. radar circuits. 2) The Logic Pulser operates by producing a large transient current for a __________ period of time. A. long B. short C. long and short D. none of the above. 7) The Sync input impedance of the LP-425 is ___________. A. 3MW.
Elenco Electronics, Inc. 150 W. Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 http://www.elenco.com e-mail: elenco@elenco.
