How to use Digital Storage Oscilloscope-DSO

How to use Digital Storage Oscilloscope

Digital  oscilloscope offer user-friendly front panel with clear indications to allow access to all basic functions for easy operation. The scaling and position buttons of all channels are optimally arranged for intuitive operation.

As design is based on the familiar practices of traditional instruments, users can use the new units without spending considerable time in learning and familiarizing with operation. For faster adjustment to ease testing there is an AUTO key to instantly display the appropriate waveform and range position.

• Dual analog channels width range : 1mV/div ~ 20V/div
•  HD colour LCD display system at 800 x 400 resolution
• Supports plug-and-play USB storage devices and capable of communicating with a computer through the USB storage device

 

• Automatic waveform and status configuration
• Storage of waveforms, setups and interfaces; waveforms and setups reproduction

 

• Fine window expansion function; precise analysis of waveform details and overview
•  Automatic measurement of 28 waveform parameters
•  Automatic cursor tracing measurement

Schematic diagram operating the front panel:-

Schematic diagram for the display interface:-

Power on the unit:- Power on the unit. Power supply voltage is 100-240 VAC, 45-440Hz. After connecting to power, let the unit carry out self-calibration to optimize the oscilloscope signal path for measurement accuracy.

Probe Compensation:-

When connecting the probe to any input channel for the first time, perform this adjustment to match the probe to the channel. Skipping the compensation calibration step will result in measurement error or fault.Please adjust probe compensation as follows:

1. In the probe menu set the attenuation factor to 10X.
Move the switch on the probe to 10X and connect the probe to CH1. If you are using the probe hook-tip, ensure a proper and secure connection. Connect the probe tip to the probe compensator’s signal output connector, and then connect the ground clamp to the earth wire of the probe compensator. Enable CH1 and press [AUTO]

2. Observe the shape of the displayed waveform.

3. If you see a “Under compensation” or “Overcompensation” waveform display, adjust the variable capacitor on the probe with a screwdriver with non-metal handle, until a “Correct Compensation”waveform illustrated above is displayed.
Overcompensation   Correct Compensation.
Probe.

1. 1X
2. 10X
3. 100X
4. 1000X

 

1. Select either one value based on the probe attenuation factor to keep
2. the vertical deflection factor reading correct. There are four values :
3. 1X, 10X, 100X and 1000X.
4. Invert Open Waveform invert function on.

Function Menu Setup:- 

• AC Intercept the DC quantities of the input signal.
• DC Pass Coupling AC and DC quantities of input signal.
• GND Disconnect input signal.
• Bandwidth limit Open Limit bandwidth to 20MHz to reduce noise display Off Full bandwidth.
• Coarse Coarse tune in steps of 1-2-5 to set up the deflection factor of the
• VOLTS/DIV vertical system. Fine Fine tune means further tuning within the coarse tune setup range to
• improve the vertical pixel aspect ratio.

Function Menu:-

       Type Math To carry out +, -, ×, ÷ functions CH1 Signal source1 Set signal source 1 as CH1 waveform, CH2 Set signal source 1 as CH2 waveform + Signal source 1 + Signal source 2 – Signal source 1 – Signal source 2,Operator × Signal source 1 x Signal source 2 ÷ Signal source 1 ÷ Signal source 2 Signal source 2 CH1 Set signal source 1 as CH1 waveform CH2 Set signal source 1 as CH2 waveform.

X-Y Mode:-

This mode is suitable for CH1 and CH2 only. After selecting the X-Y display mode, the horizontal axis will display CH1 voltage, while the vertical axis will display CH2 voltage.
Waveform display in X-Y mode

Caution: In the normal X-Y mode, the oscilloscope can use the random sampling rate to acquire waveforms. To adjust sampling rate and channel vertical range in the X-Y mode, the omitted sampling rate is 100MS/s. Generally, through adjusting time base range, lower the sampling rate appropriately will result in lissajous figures of better display quality. The following functions have no effect in the X-Y display mode:

• Auto measurement mode
• Cursor measurement mode
• Reference or math waveform
• Vector display type
• Horizontal Menu knob

Alternate Trigger When alternate trigger is selected, the trigger signal will be present in two vertical channels. This triggering mode is suitable for observing two signals of unrelated signal frequencies. The figure below shows the alternate trigger waveform. Trigger menus are below

X-Y function:-

To check the phase difference between two channels. Example: To measure the phase variation when a signal passes through the circuit, connect your oscilloscope to the circuit and monitor the input and output signals. To check the circuit’s input and output in the X-Y coordinate graph, follow the steps below:

• Set the attenuation factor of the probe to 10X. Set the switch of the probe to 10X.
• Connect the CH1 probe to the input terminal of the network. Connect the CH2 probe to the output terminal of the network.
•  If the channel is not displayed, press the [CH1] and [CH2] menu button to enable the two channels.
•  Press [AUTO].

 

• Adjust the vertical scaling knob to make the displayed amplitude of the two channels to about equal.
• Press the [DSIPLAY] menu key in the horizontal control zone to recall the horizontal control menu.

 

•  Press [F2] to select X-Y. The oscilloscope will display the circuit’s input and output characteristics in a Lissajous figure.
• Adjust the vertical scale and vertical position knob to achieve the best waveform result.
•  Using the elliptic oscilloscope display graph to observe, measure and calculate the phase difference If sin θ = A/B or C/D.