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Logic Pulser Kit
User Manual
12 pgs394.24 Kb0

Elenco Logic Pulser Kit User Manual

LOGIC PULSER KIT
MODEL LP-425K
Assembly and Instruction Manual
Elenco Electronics, Inc.
Copyright © 1995 Elenco Electronics, Inc. REV-D Revised 2002 753262
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. Symbol Description Color Code Part #
2 R1, R16 100W 5% 1/4W brown-black-brown-gold 131000 1 R17 470W 5% 1/4W yellow-violet-brown-gold 134700 2 R11, R13 2kW 5% 1/4W red-black-red-gold 142000 3 R12, R14, R15 20kW 5% 1/4W red-black-orange-gold 152000 1 R8 68kW 5% 1/4W blue-gray-orange-gold 156800 4 R2, R7, R9, R10 100kW 5% 1/4W brown-black-yellow-gold 161000 1 R5 1MW 5% 1/4W brown-black-green-gold 171000 2 R3, R6 1.8MW 5% 1/4W brown-gray-green-gold 171800 1 R4 10MW 5% 1/4W brown-black-blue-gold 181000
CAPACITORS
Qty. Symbol Description Part #
2 C6, C7 100pF (101) Discap 221017 1 C4 .001mF (102) Mylar 231017 1 C3 .01mF (103) Mylar 241017 1 C1 .1mF (104) Discap 251010
Qty. Symbol Description Part #
1C5 1mF Tantalum 260010 1 C8 10mF Lytic 35V 271016 1 C2 22mF Lytic 25V 272245
SEMICONDUCTORS
Qty. Symbol Description Part #
Qty. Symbol Description Part #
2 Q2, Q3 2N3906 Transistor 323906 1 U1 IC 4069 or 74C04 334069
1 D6 LED 350001
MISCELLANEOUS
Qty. Description Part #
1 PC Board 517009 1 Switch SPDT 541024 1 Pulser Tip 616001 1 Case 623005 2 Screw #4 x 5/8” 643450 1 IC Socket 14-pin 664014 3 Pins 665001 1 Alligator Clip Black 680001
Qty. Description Part #
SPECIFICATIONS
Maximum Allowable Supply Voltage +20V, +25V/15 sec. Maximum Allowable Voltage on Output + Maximum Sync. Input Voltage +120V/15 sec. Operating Supply Voltage Range 4 - 15VDC Free Air Operating Temperature Range 0 - 50 Output Pulse Width at 100mA Load 10mS Output Current
1) Pulser Mode 100mA Sink/Source
2) Square Wave Output 5mA Sink/Source Pulse Repetition Rate .5PPS / 400PPS Sync. Input Impedance 1MW
35V
O
C
-1-
or 34C004
IDENTIFYING RESISTOR VALUES
Use the following information as a guide in properly identifying the value of resistors.
Bands
1 2
Multiplier
Tolerance
BAND 1
1st Digit
Color Digit Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Gray 8 White 9
BAND 2
2nd Digit
Color Digit Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Gray 8 White 9
IDENTIFYING CAPACITOR VALUES
Capacitors will be identified by their capacitance value in pF (picofarads), nF (nanofarads), or mF (microfarads). Most capacitors will have their actual value printed on
Second Digit
First Digit
103K
100V
The value is 10 x 1,000 = 10,000pF or .01mF 100V
Multiplier
Multiplier
Tolerance*
Maximum Working Voltage
Multiplier
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 0.1
them. Some capacitors may have their value printed in the following manner. The maximum operating voltage may also be printed on the capacitor.
For the No.01234589 Multiply By 1 10 100 1k 10k 100k .01 0.1
10mF 16V
Note: The letter “R” may be used at times to signify a decimal point; as in 3R3 = 3.3
*
The letter M indicates a tolerance of +20% The letter K indicates a tolerance of + The letter J indicates a tolerance of +5%
Color Tolerance Silver +10% Gold +5% Brown +
1% Red +2% Orange +3% Green +
.5% Blue +.25% Violet +.1%
10%
INTRODUCTION
Assembly of your LP-425 Logic Pulser 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 in identifying the proper components and in good
CIRCUIT DESCRIPTION
The Elenco Model LP-425 Logic Pulser is a very handy device for inspecting and repairing logic circuits. By injecting a signal directly to the circuit, you can avoid removing the ICs or other circuit components. The Logic Pulser will thus help you to troubleshoot wiring errors and malfunctioning components. The Logic Pulser operates by producing a large transient current for a short period of time. This will not harm the components under test since the average current is very small. The injected voltage is produced by the transient current flowing through the inherent resistance of the circuit.
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”. Avoid making mistakes and no problems will occur.
The LP-425 Logic Pulser can produce a 10 microsecond pulse at 100mA load. The signal frequency can be set to .5Hz or 400Hz by the pulse repetition rate switch on the front of the Logic Pulser. This feature makes the Logic Pulser a very effective tool. The Logic Pulser also has a square wave output terminal (SQ). When the pulse repetition rate switch is set to 400Hz, the signal on the square wave terminal is a square wave. When the switch is set to .5Hz, the signal on the terminal is a pulse, high for 90% of the time and ground for the remaining 10%. The sync input terminal (SYNC) Logic Pulser can be used to produce an externally synchonized signal at the output.
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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. Solder contains lead and is a toxic substance. Wash your hands thoroughly after handling solder.
• Be sure that there is adequate ventilation present.
Assemble Components
In all of the following assembly steps, the components must be installed on the top side of the PC board unless otherwise indicated. The top legend shows where each component goes. The leads pass through the corresponding holes in the board and are soldered on the foil side.
Use only rosin core solder of 63/37 alloy.
Foil Side
DO NOT USE ACID CORE SOLDER!
What Good Soldering Looks Like
A good solder connection should be bright, shiny, smooth, and uniformly flowed over all surfaces.
1. Solder all components from
the copper foil side only. Push the soldering iron tip against both the lead and the circuit board foil.
2. Apply a small amount of
solder to the iron tip. This allows the heat to leave the iron and onto the foil. Immediately apply solder to the opposite side of the connection, away from the iron. Allow the heated component and the circuit foil to melt the solder.
3. Allow the solder to flow
around the connection. Then, 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.
Component Lead
Foil
Solder
Foil
Solder
Foil
Soldering Iron
Circuit Board
Soldering Iron
Soldering Iron
Mount Part
Bend Leads to
Hold Part
Solder and
Cut Off Leads
Types of Poor Soldering Connections
1. Insufficient heat - the
solder will not flow onto the lead as shown.
2. Insufficient solder - let the
solder flow over the connection until it is covered. Use just enough solder to cover the connection.
3. Excessive solder - could
make connections that you did not intend to between adjacent foil areas or terminals.
4. Solder bridges - occur
when solder runs between circuit paths and creates a short circuit. This is usually caused by using too much solder. To correct this, simply drag your soldering iron across the solder bridge as shown.
Rosin
Soldering iron positioned incorrectly.
Solder
Component Lead
Solder
Soldering Iron
Foil
Gap
Drag
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