velleman K7103 Digital Storage PC Oscilloscope User Manual

velleman K7103 Digital Storage PC Oscilloscope

DIGITAL STORAGE PC OSCILLOSCOPE

Any hobbyist’s laboratory needs an oscilloscope, but funds are usually insufficient for acquiring such a device. This kit thus represents a very good, and cheaper alternative to anyone who already has a computer. The K7103 is a digital memory oscilloscope that is operated from any IBM compatible computer using the computer screens as the oscilloscope display. All standard oscilloscope functions are available from the DOS program supplied. Operation seems like a normal oscilloscope, with one difference that most operations are performed using the mouse. Markers are included and are a user-friendly way of indicating voltage and frequency and can easily be operated also with the mouse. Connection is via the parallel port of the computer. The oscilloscope has two completely separated channels with a maximum sampling frequency of 32MHz. Any waveform on the screen can be stored in TIFF format so that it may be retreived later for use in documentation or for comparison to other waveforms. All components for using the oscilloscope with one channel are supplied. The components for the second channel are available in a separate kit with reference nº:K7104.

TECHNICAL DATA

General:

• Two separate channels (channel 2 is optional)
•  Markers for voltage and frequency
• Input sensitivity: 10mV to 5V / division
•  Input impedance: 1Mohm // 30pF
• Maximum input voltage: 100V (AC+DC)
•  Input coupling: DC, AC en GND
•  Supply voltage: 9 – 12VDC / 700mA
•  Dimensions: 200x65x160mm

Horizontal deflection:

• Time base: 100ns to 100ms / division

Triggering:

• Trigger source: CH1, CH2 of free run
• Triggering slope: positive of negative
•  Trigger level: adjustable by ½ division

Digitization:

• Vertical resolution: 8 bit
•  File format: TIFF 320×256 black/white
•  Sampling frequency: 32MHz. (max.)
• Memory: 4Kb / channel
•  Interpolation: linear or rounded

Minimum system requirements:

•  IBM compatible PC
•  VGA display card
•  Mouse
•  An available printer port LPT1
•  400Kb conventional memory available
• MS Windows 3.1 or later version is necessary for accessing the assembly instructions.

USE

ATTENTION, VERY IMPORTANT!
The oscilloscope earth is connected directly to the computer earth. The probe earth must NEVER be connected to any potential other than the PC earth.
Safe equipment is:
Battery supplied equipment
Equipment supplied via a transformer or adapter.
Potentially hazardous equipment is:
Equipment connected directly to mains (eg. old TV sets). Equipment that contains components that are connected directly to mains (eg. dimmers). If such devices are to be measured then an isolating transformer has to be used for connecting this equipment. If the PC earth is connected to the MAINS earth, and the earth of the oscilloscope probe is accidentally connected to mains voltage, a high current will flow through the oscilloscope and the PC. This can destroy the oscilloscope and computer.
COMMANDS ON THE OSCILLOSCOPE:
Potentiometers RV2 and RV5: Y POSITION, are used to adjust the vertical position on the screen.
Switches SW1 an SW2 have three positions:
AC: The input signal is capacitatively coupled to the input amplifier/attenuator. Only AC components are measured.
GND: The input signal is interrupted and the input amplifier/attenuator is set to ground. Use this setting to select a reference point on the screen.
DC: The input signal is directly coupled to the input amplifier/attenuator. AC (alternating current) as well as DC (direct current) are measured.
COMMANDS ON THE SCREEN:
Start the SCOPE.COM programme. This is a DOS programme but can generally be run from Windows by double clicking on the SCOPE icon in the K7103 programme group.
Select a value by clicking on the right number ON/OFF Turn on / Turn off a channel
VOLTS/DIV Indication of the peak-to-peak value needed to fill one division TRIG ON/OFF Select “free run” or “Trigger”
TRIG LEVEL Adjustment of the trigger level, a mark on the screen indicates the level
TRIG CH Select the trigger source: channel 1 or channel 2
EDGE Select the triggering slope, positive slope ↑ or negative slope ↓
RUN ON/OFF Update screen continuously (RUN) or freeze screen (OFF)
SINGLE Update the screen only once after the trigger level has been reached (only if the device is set to RUN OFF!)
X-POSITION Scroll the signal horizontally on the screen. A blue line represents the trigger reference level. Press 0 to return to the previous state.
SAVE Save the current signal on disk, the name is rendered automatically until a key is pressed.
EXIT Leave the program TIME/DIV Time indication between two divisions
L/S Since a digital signal is composed of dots, it may be necessary to connect the distance between two dots in order to obtain a smooth curve. This button allows you to choose between rounded interpolation S (best to use for higher frequencies) and linear interpolation L for slow signals.
The L/S selector only works with TIME/DIV positions 0.5, 0.2 and 0.1µS.

Zoom and scroll function

A still image can be zoomed in simply by changing the position of the TIME/DIV switch.The original signal. Time scale 20µ’s/DIV Same signal on tiime scale 5µS/DIV Trigger level reference point in x direction is rendered on the screen. Pre-trigger function allows the user to view the signal before the triggering.
Use of the markers:
Four markers are available: two horizontal for measuring voltage, and two vertical for measuring time and frequency. The markers can be made to appear as follows: FOR VOLTAGE:

• Move the mouse to the upper edge of the signal screen.
• Press on the left-hand mouse button and keep it pressed in, then drag the marker into the signal window.
•  The second marker can be made to appear in the same way.
•  The voltage between the two markers can be read from the bottom left.

Note:
The markers in channel 1 have precedence if both channels are being used. FOR TIME AND FREQUENCY:

•  Move the mouse to the left-hand edge of the signal screen.
•  Press on the left-hand mouse button and keep it pressed in, then drag the marker into the signal window.
•  The second marker can be made to appear in the same way.
• The time between the two markers, as well as the converted frequency, can be read from the bottom right.

Note:
When enlarging the screen it is possible for the vertical markers to disappear to the left or right of the screen. If this happens they can be retrieved from the edge that they went into in the same way as described above.
How to avoid interference (aliasing) with the sampling frequency:
Due to interference between the incoming signal and the sampling frequency, it may be that the signal on the screen is not correct in frequency; in order to avoid this, begin the time base at as high a value as possible (0.1µs) when reading unknown signals. The sampling frequency should at least be twice as high as the signal to be measured (see table below).

TIME/DIV
settings

| Shown sampling frequency in RUN mode| Real sampling frequency (Sampling rate)
---|---|---
0,1 us| 32 MHz| 32 MHz
0,2 us| 32 MHz| 32 MHz
0,5 us| 32 MHz| 32 MHz
1 us| 32 MHz| 32 MHz
2 us| 16 MHz| 32 MHz
5 us| 6,4 MHz| 32 MHz
10 us| 3,2 MHz| 16 MHz
20 us| 1,6 MHz| 8 MHz
50 us| 640 KHz| 3,2 MHz
0,1 ms| 320 KHz| 1,6 MHz
0,2 ms| 160 KHz| 800 KHz
0,5 ms| 64 KHz| 320 KHz
1 ms| 32 KHz| 160 KHz
2 ms| 16 KHz| 80 KHz
5 ms| 6,4 KHz| 32 KHz
10 ms| 3,2 KHz| 16 KHz
20 ms| 1,6 KHz| 8 KHz
50 ms| 640 Hz| 3,2 KHz
100 ms| 320 Hz| 1,6 KHz

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>