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Logic Pulser Kit
User Manual
12 pgs394.24 Kb0

Elenco Logic Pulser Kit User Manual

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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
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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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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).
R11 - 2kW Resistor
(red-black-red-gold)
(see Figure 1)
R14 - 20kW Resistor
(red-black-orange-gold)
R9 - 100kW Resistor
(brown-black-yellow-gold)
R7 - 100kW Resistor
(brown-black-yellow-gold)
R10 - 100kW Resistor
(brown-black-yellow-gold)
R6 - 1.8MW Resistor (brown-gray-green-gold)
R13 - 2kW Resistor
(red-black-red-gold)
R3 - 1.8MW Resistor (brown-gray-green-gold)
R12 - 20kW Resistor
(red-black-orange-gold)
(see Figure 1)
R15 - 20kW Resistor
(red-black-orange-gold)
R17 - 470W Resistor
(yellow-violet-brown-gold)
R8 - 68kW Resistor
(blue-gray-orange-gold)
R4 - 10MW Resistor
(brown-black-blue-gold)
R2 - 100kW Resistor
(brown-black-yellow-gold)
R5 - 1MW Resistor
(brown-black-green-gold)
R16 - 100W Resistor
(brown-black-brown-gold)
R1 - 100W Resistor
(brown-black-brown-gold)
Figure 1
Stand resistor on end.
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ASSEMBLE COMPONENTS TO THE PC BOARD
Refer to the top legend on the PC board, install and solder the following diodes and capacitors.
D5 - 1N4001 Diode
(see Figure 2)
C8 - 10mF Lytic Capacitor
(see Figure 3A)
C6 - 100pF Discap
(may be marked 101)
C7 - 100pF Discap
(may be marked 101)
D3 - 1N4148 Diode
(see Figure 2)
C5 - 1mF Tantalum
(May marked 105)
(see Figure 3B)
D4 - 1N4001 Diode
(see Figure 2)
D2 - 1N5246 Zener Diode
(see Figure 2)
C2 - 22mF Lytic Capacitor
(see Figure 3A)
D1 - 1N4001 Diode
(see Figure 2)
C3 - .01mF Mylar Capacitor
(May be marked 103)
C4 - .001mF Mylar Capacitor
(May be marked 102)
Figure 2
When mounting diodes horizontally, mount as indicated by the band (diodes have polarity).
Band
C1 - .1mF Discap
(may be marked 104)
Figure 3A
Polarity Mark
(–) (+)
Figure 3B
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(–) (+)
Some capacitors have polarity markings indicating the positive (+) or negative (–) lead. The PC board is marked to show the lead positions.
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)
Q4 - 2N3904 Transistor
(see Figure 7)
Q5 - 2N3904 Transistor
(see Figure 7)
Q2 - 2N3906 Transistor
(see Figure 7)
Figure 4
Tin Here
Figure 5
Install and solder the IC socket. Insert the IC into the socket with the notch in the direction shown on the top legend.
D6 - LED
(see Figure 8)
Q1 - 2N3904 Transistor
(see Figure 7)
U1 - 14-Pin IC Socket U1 - 74C04 IC or 4069
(see Figure 5)
SW1 - Switch
(see Figure 6)
P1, P2, P3 - Pins Do not install the pins to the PC board. They will be installed later. Tin (that is, put a small amount of solder on) the foil around the holes for the three pins. Do not block the hole. Tin the bottom fo the pin as shown in Figure 4.
Figure 7
Mount the transistor with the flat side in the direction shown on the top legend. Leave 1/4” between the part and PC board.
Notch
Figure 6
Insert the tabs and terminals into the PC board. Solder terminals only.
Ta b
Ta b
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1/4”
Figure 8
Cut a 3/8” piece of tubing for each LED lead, to be used as stand-offs. Mount the LED with the flat side in the direction shown on the top legend.
Flat
Tubing
3/8”
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). Solder the ribbed wire to the hole marked “+” and the smooth wire to the hole marked “–”.
Install the pulser tip as shown in Figure 10. Using the 1 1/2” wire, strip 1/4” of insulation off of both ends. Solder one end to point P on the PC board. Solder the other end of the wire to the pulser tip groove.
Punch out the five holes in the front label. Peel the backing off the front and back labels and stick them to the case as shown in Figure 11. The front label should be placed toward the back of the indent (toward the 3 pins) so that the LED and switch holes align with the case holes.
Insert the 3 pins P1, P2, and P3 into their holes in the front label. Insert the PC board into the case so that the LED and switch protrude through the label (see Figure 11). Insert the 3 pins into the PC board and solder (see Figure 4).
Place the unit into the case bottom and fasten with two #4 screws. Do not over-tighten or the holes may strip out.
Cut a 13/16” piece of red shrink tubing and slide it over the pulser tip until it touches the plastic case. Shrink the tubing by heating it with your soldering iron. Be sure the soldering iron does not contact the tubing or plastic case.
This completes the assembly procedure. Your Logic Probe is now ready for testing.
Solder the wire to the clip, then bend the tabs over the insulated wire.
Clip
Ribbed Wire
Smooth Wire
Front Label
Place knot in case
Back Label
#4 x 5/8” Screws
Case (top)
Assembled PC Board
Case (bottom)
Figure 10 Figure 11
Figure 9
Red Shrink Tubing
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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.
Set the pulse repetition rate switch to the 0.5PPS position. Check the red LED. It should blink once every 2 seconds (0.5PPS). Set the switch to 400PPS. The Logic Pulser generates a frequency of 400Hz. At this frequency, the LED flashes at a rate that makes it appear to be on continuously. If either of these tests fail:
a) Check the input cable. The ribbed wire with the
red alligator clip should go to the hole marked (+).
b) Check for cold solder joints and solder bridges
around the IC. Check that the IC notch matches the notch shown on the PC board.
c) Check the soldering and polarity of diodes D1,
D2, D3 and D6 (LED).
d) Check that transistor Q5 is the correct type and
is mounted with the flat side as shown on the PC board.
e) Check the soldering and the values of capacitors
C1 through C5.
f) Check the soldering and the values of resistors
R1 through R5 and R15 through R17.
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. If you do not get these waveforms:
a) Check the value and soldering of R16. b) Check that transistor Q5 is the correct type and
is mounted with the flat as shown on the PC board.
c) Check the value and soldering of capacitors C3,
C4 and C5.
Connect the pulser tip to the resistor combinations shown in Figure 12 and observe the waveforms shown for the pulser tip. If you do not get these waveforms:
a) Check that transistors Q1 through Q4 are the
correct type and are mounted with the flat side as shown on the PC board.
b) Check the soldering and polarity of diodes D4
and D5.
c) Check the soldering and values of resistors R7
through R14.
d) Check the soldering and values of capacitors C3
through C8.
Figure 12
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SCHEMATIC DIAGRAM
Schematic Diagram
IC 74C04 or 4069
LP-425
Note: All resistors are 5% 1/4W
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QUIZ
1) The LP-425 Logic Pulser can produce a _______ microsecond pulse at 100mA.
A. 30 B. 15 C. 10 D. 20
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.
3) The signal frequency of the Logic Pulser are _____ Hz and _____ Hz.
A. 10, 100 B. 0.1, 300 C. 0.5, 400 D. none of the above.
4) The Logic Pulser also has a ___________ wave output terminal.
A. square B. sine C. saw D. cosine
5) In operating supply voltage range is ____________.
A. 0V to 10VDC. B. 4V to 15VDC. C. 20V to 45VDC. D. 0.1V to 5VDC.
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.
7) The Sync input impedance of the LP-425 is ___________.
A. 3MW. B. 2MW. C. 4MW. D. 1MW.
8) When the switch is set to 0.5Hz, the signal on the terminal is a pulse, high for ________ of the time and ground for the remaining _________.
A. 50%, 50%. B. 20%, 80%. C. 90%, 10%. D. 60%, 40%.
9) The Sync Input Terminal (SYNC) Logic Pulser can be used to produce an externally synchronized signal at the ____________.
A. output. B. input. C. input and output. D. none of the above.
10) The Free air operating temperature range is ______.
A. 0 - 100 B. 30 - 40OC. C. 0 - 50OC. D. 25 - 75
O
C.
O
C.
Other Logic Probe Kits Available
Logic Probe Model LP-525K (kit)
Digital Logic Probe in kit form provides convenient and precise use in measurement of logic circuits. It displays logic levels (high or low), pulses and voltage transients down to 30 nanoseconds and a maximum input of 20MHz. Large PC board and detailed manual for fast construction.
Logic Probe Model LP-535K (kit)
Advanced design with audible sound for signal detection in logic circuits. It displays logic levels (high or low) pulses and voltage transients down to 10 nanoseconds. High intensity LED readouts provide instant response to the logic state. Simplified circuitry for fast construction. Detailed instructions, illustrations and testing included.
Answers to Quiz: 1. C; 2. B; 3. C; 4. A; 5. B; 6. B; 7. D; 8. C; 9. A; 10. C
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Elenco Electronics, Inc.
150 W. Carpenter Avenue
Wheeling, IL 60090
(847) 541-3800
http://www.elenco.com
e-mail: elenco@elenco.com
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