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How to Make a TV Oscilloscope

Fundamentally, there are two types of electrical signals and these carry a direct current (DC) or an alternating current (AC). DC electrical signals operate at constant voltage and have no variation with time. This type of electricity is generated by batteries. AC electrical signals have a sinusoidal dependence with time and the voltage oscillates at a set frequency. Oscilloscopes are devices that are used to visualize AC electrical signals. A simple oscilloscope can be made using a personal computer with TV (monitor), and a data acquisition card.

Things You'll Need

Personal computer with USB 2 port
National Instruments USB data acquisition card
USB cable
Signal generator
BNC coaxial cable

Instructions

- 1
  Switch on the personal computer. Insert the CD that came with the digital acquisition card and install the "Signal Express" software and the device driver for the card.
- 2
  Plug the small socket on one end of the power supply lead into the digital acquisition card. Plug the opposite end into the electrical mains. Plug the USB cable between the digital acquisition card and the personal computer. The computer should make an audible beep indicating that it has detected the new hardware.
- 3
  Plug the BNC coaxial cable between the output of the signal generator and one of the inputs on the digital acquisition card. Switch on the signal generator, press the square wave button and set a frequency of 10 Hz.
- 4
  Launch the "Signal Express" software. In the first window, click on the radio button, "Create new project." In the second window that appears, select "Acquire signal, analogue input, voltage." A new screen appears displaying all of the available inputs channels. These are labeled A0-A1. Select the input which the coaxial cable is plugged into (it will be written next to the input on the card). Click "Finish" to get into the main acquisition screen. To visualize the signal in oscilloscope mode, click on the "Data View" tab at the top of the window and click "Run." An oscilloscope graph appears with the square wave signal. The oscilloscope graph auto scales so further adjustments are necessary. A simple oscilloscope with TV (Real-time signal graph) has been created.

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