Elenco Electronics LP-535K Instruction & Assembly Manual

LOGIC PROBE KIT

MODEL LP-535K

Instruction & Assembly Manual

Elenco Electronics, Inc.

Copyright © 1999 Elenco Electronics, Inc. Revised 2002 REV-A 753272

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. DO NOT contact your place of purchase
as they will not be able to help you.

RESISTORS

Qty. Symbol Description Color Code Part #

1 R4 470Ω 1/4W 5% yellow-violet-brown-gold 134700
4 R5, R6, R7, R9 1kΩ 1/4W 5% brown-black-red-gold 141000
2 R1, R11 20kΩ 1/4W 5% red-black-orange-gold 152000
1 R10 33kΩ 1/4W 5% orange-orange-orange-gold 153300
1 R3 560kΩ 1/4W 5% green-blue-yellow-gold 165600
1R2 1MΩ 1/4W 5% brown-black-green-gold 171000
1 R8 15MΩ 1/4W 5% brown-green-blue-gold 181500

CAPACITORS

Qty. Symbol Value Description Part #

1 C1 68pF Discap (68) 216816
1 C2 220pF Discap (220) 222210
2 C3, C4 .001µF Discap (102) 231036
1C6 .01µF Discap (103) 241031
1C7 .1µF Discap (104) 251010
1C5 .47µF 50V Electrolytic (Lytic) 254747
1C8 47µF 10V Electrolytic (Lytic) 274742
1C9 47µF 50V Electrolytic (Lytic) 274747

SEMICONDUCTORS

Qty. Symbol Value Description Part #

2 D8, D10 1N4001 Diode (epoxy) 314001
4 D2, D3, D4, D9 1N4148 Diode (glass) 314148
1 D1 1N5232 Zener Diode 5.6V (bag with capacitors) 315232
1 D5 L-323 GD LED Green Triangular 35323G
1 D6 L-323 ID LED Red Triangular 35323I
1 D7 L-934 YDT LED Yellow 359344
1 U2 3086 Integrated Circuit 333086
1 U1 74HC14 Integrated Circuit 39HC14

MISCELLANEOUS

Qty. Symbol Description Part #

1 PC Board 517030
1 SP1 Speaker 40Ω 521602
1 S1 Switch Slide SPDT 541025
1 Logic Probe Tip 616000
1 Case (two parts) 623019
2 U1, U2 Socket IC 14-pin 664014
1 Label 724009
1 Manual 753272
1 Cord Power 863080
4” Tubing #20 890020

0.6” Shr ink Tubing Red 3/32” 891020
1 Solder Tube 9ST4

-1-

-2-

IDENTIFYING RESISTOR VALUES

Use the following information as a guide in proper ly identifying the value of resistors.

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

Multiplier

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

Resistance

Tolerance

Color Tolerance
Silver +

10%

Gold +

5%

Brown +

1%

Red +

2%

Orange +

3%
Green +.5%
Blue +.25%
Violet +

.1%

Bands

1 2

Multiplier

Tolerance

IDENTIFYING CAPACITOR VALUES

Capacitors will be identified by their capacitance value in pF (picofarads), nF (nanofarads), or µF (microfarads). Most
capacitors will have their actual value printed on them. Some capacitors may have their value printed in the following manner.

Resistors

Capacitors

PARTS IDENTIFICATION

Switch

Speaker

Discap

Diodes

Epoxy

Glass

Integrated Circuit (IC)

IC Socket

LEDs

Yellow

Integrated Circuits

Green Red

Tip

Tubing

Top Cover

Bottom Cover

Power Cord

Label

PC

Board

+

Electrolytic

The value is 10 x 1,000 =
10,000pF or .01µF 100V

The letter M indicates a tolerance of +

20%
The letter K indicates a tolerance of +10%
The letter J indicates a tolerance of +

5%

Note:

The letter “R” may be used at times to

signify a decimal point; as in 3R3 = 3.3

Second Digit

First Digit

Multiplier

Tolerance

103K

100V

Maximum Working Voltage

For the No.01234589
Multiply By 1 10 100 1k 10k 100k .01 0.1

Multiplier

The LP-535 Logic Probe Kit tests different types of digital logic circuit families.
Working Voltage 4 - 16VDC

Current Consumption Max 5mA @ 5V

Max 15mA @ 15V
Frequency Response Over 50MHz
Minimum Detectable
Pulse Width 10nsec
Input Impedance 1MΩ
Input Overload Protection 70V AC/DC (10s)
Supply Voltage Protection 50V AC/DC (10s)
Operation Temperature 0

O

C to 50OC

Switch Selectable Audio Indicator HI Level

CIRCUIT DESCRIPTION

SPECIFICATIONS

-3-

INPUT LED STATES SOUND

SIGNAL LO HIGH PULSE

Probe not connected to power.

*

Interpreting

the LEDs

LED On
LED Off
LED Blinking
No Sound
Sound

*

*

Logic tip is not connected or Logic “0” no
pulse activity.

Logic “1” no pulse activity.

Logic “0” with positive single pulses.

Logic “1” with negative single pulses.

Logic “0” with positive continuous pulses.

Logic “1” with negative continuous pulses.

This information for switch to the sound position.

The Elenco Model LP-535 Logic Probe Kit is a
convenient and precise instrument for use in the
measurement of logic circuits. It displays logic levels
(high or low), sounds high level, and voltage
transients down to 10 nanoseconds. To detect the
high and low logic levels, the LP-535 uses two
inverters, U1A and U1B (see the Schematic
Diagram). One inverter dr ives the LO (green) LED
and the other, the HI (red) LED.

The red LED lights when the input voltage is more
than 50% of the supply voltage. The function of the
switch for TTL or CMOS levels input signal makes up
the special circuit on the base of transistors from U2

and additional components. The outputs of U1A and
U1B are connected to differential circuits C3/R3 and
C4/R7. These differential circuits select signals,
when the test signals are the pulses. After the
differential circuits, the short pulses go through
inverters U1C and U1D to the yellow LED. This LED
blinks when the detecting diode D4 opens. At this
time, capacitor C6 discharges. The lit time of the
yellow LED depends upon the value of C6. The LP­535 is equipped with a sound circuit. When the input
signal is HI, the oscillator (U1E, U1F) is started and
the frequency through switch S1 passes to the
speaker.