The oscilloscope is arguably one of the most useful general purpose tools ever created for use by electronic engineers. This oscilloscope is not intended for professional use, but a great learning experience and educational. Introduction to oscilloscope before you begin prerequisite labs introduction to matlab expected knowledge ohms law. Analog, digital storage, and digital phosphor oscilloscopes. This tube, is commonly used to obtain a visual display of. Mar 17, 2017 this book is about how i built a dual trace sound card oscilloscope, calibrator and signal generator project from start to finish. This tube, is commonly used to obtain a visual display of electronic information in oscilloscopes, radar systems, television receivers, and computer monitors. Crt oscilloscope more of an audiovisual display how to make a crt tv into an oscilloscope. Looking at the face of the instrument, you are viewing the screen that the electron beam strikes. Oscilloscope lexicon a glossary covering some of the more common oscilloscope characteristics. When troubleshooting a malfunctioning oscilloscope.
This is quite a nice piece of test equipment, if not a little bit old made in the early 90s. Since its invention more than 100 years ago, new types, features and functionalities have been introduced. A crt makes available a large number of electrons which are accelerated to high velocity and are brought to focus on a fluorescent screen where it produces a spot when strikes it. The cathode ray tube example 7 on an accelerated electron see lesson 1 describes a portion of a cathode ray tube crt. The cursor function allows measurement and digital display on the crt of voltage. There is a combining network akin to a loudspeaker crossover. The monitor in question is a combined colour tv, radio and cassette player that i hope to rip the innards out of and turn into a nice oscilloscope. The oscilloscope is a tool commonly used by engineers and technicians to analyze and. Buy the catahoula technologies oscilloscope crt driver pcb. On older analog scopes this is a cathoderay tube or crt. Using an oscilloscope tips and tricks for someone using an oscilloscope for the first time. The pcb was mainly designed to drive a 2inch to 3inch oscilloscope crt, but some 5inch crts will work.
Beginner oscilloscope tutorial contd once youve learned the basic oscilloscope controls, here are a few other things that you should know about. I describe all the circuits and how to build them into small cases that sit nicely on your desk. The crt is a special type of vacuum tube in which electrons, emitted when the cathode is heated, are shaped into a narrow beam and accelerated to a high velocity before striking a phosphorcoated screen. In my senior year of high school, i ripped apart an old crt monitor and replaced the horizontal drive signal with the output of an audio amplifier. While similar in function to the crt used in televisions, oscilloscope display tubes are specially built for the purpose of serving an a measuring instrument. Oct 26, 2011 had an old dell crt monitor laying in the corner and decided to do something with it. The screen glows at the point where the electron beam strikes. Short descriptions of the available features are as follows.
When set to 1x, the oscilloscope will display the actual signal to scale. Had the idea in my head to make an oscope, and i found online that there were others that had already done it. However, the video camera apparently cannot record color from the monitor screen for some reason. Anatomy of an oscope an overview of the most critical systems on an oscilloscope the screen, horizontal and vertical controls, triggers, and probes. The basic component of an oscilloscope is the cathoderay tube crt, figure 1. Push the frontpanel default setup button to set the oscilloscope to a known starting point.
An oscilloscope, previously called an oscillograph, and informally known as a scope or oscope. Oscilloscope basics all oscilloscopes share certain basic features. Introduction to the oscilloscope purdue university. Oscilloscopes basic use and measurements by paul harden, na5n page 3 of 12 somewhere. Gmbh, a major manufacturer of both combiscopes and analog scopes. The oscilloscope oscilloscope operation x vs y mode an oscilloscope can be used to measure voltage. Crt oscilloscope lcd mod motivation matts projects. The cathode ray tube or crt is a vacuum tube of special geometrical shape which converts an electrical signal into a visual one. The voltage drop is amplified and used to deflect an electron beam in either the x horizontal or y vertical axis using an electric field. Learn how with this video tutorial, which offers stepbystep instructions on setting up and adjusting an old cathode ray tube oscilloscope for the measurment of signals. In an oscilloscope, the beam is deflected horizontally x by a. As automated measurements become ever more complex, many of the key considerations, such as probing, sampling, vertical and. Suppose you want to combine pdf files named example1.
Oscilloscope fundamentals case school of engineering. For more information, or to get started using your own oscilloscope, take a look. How to use a crt oscilloscope other devices wonderhowto. On older analog scopes, these are mostly controlled by a dedicated switch for each function. Color problems when turning a crt tv set into an oscilloscope. Probe compensation before using the oscilloscope probe, the oscilloscope must be calibrated, or compensated, to account for the nonideal effects that the probe has on voltage measurements.
This homemade tube oscilloscope is based on the waterman pocketscope 0510a, a 3 tube oscilloscope made in 1946. The electron gun produces a beam of highspeed electrons focused to a small spot on the screen. A chemical phosphor coated on the crt creates a glowing trace wherever the beam hits. The cathode ray tube crt consists of an electron gun, deflecting apparatus, and luminescent screen. Some analog oscilloscopes display a second trace for the delayed sweep rather than combine them as. What is crt and what is its use in an oscilloscope. The heart of the oscilloscope is a cathode ray tube or crt, of the sort you have already studied.
When set to 10x, the oscilloscope reading will be one tenth of the actual signal. It does this by measuring the voltage drop across a resistor and in the process draws a small current. Jan 25, 2016 last semester i was given a decommissioned hp 1662as logic analyzeroscilloscope from mit. Ive recorded my steps in detail so that you can build one too. Primer xyzs of oscilloscopes university of colorado boulder. Then the test leads must be connected to the oscilloscope inputs. The signal voltage deflects the beam up and down proportionally, tracing the waveform on the screen. Mar 16, 2007 oscilloscope built from an old monitor. Compact portable oscilloscope crt readout and cursor function set values using the crt readout function and measured values using the cursor function can be displayed with letters and numbers. Electronic circuits in the scope apply voltages to one set of deflection plates to sweep the beam across the screen from left to right at a constant rate, thereby providing the time axis. Besides its awkward shape, weight and high voltage requirements, the crt offers many advantages over its competitors. The core of an analog oscilloscope is a special type of vacuum tube known as a cathode ray tube, or crt. An oscilloscope, previously called an oscillograph, and informally known as a scope or oscope, cro for cathoderay oscilloscope, or dso for the more modern digital storage oscilloscope, is a type of electronic test instrument that graphically displays varying signal voltages, usually as a twodimensional plot of one or more signals as a function of time.
As used in an oscilloscope, its a funnelshaped glass bottle with a flat bottom which is the screen and a long, narrow neck. As opposed to other display systems that require a driver for each picture element pixel, the crt requires a single driver to drive the tubes cathode or. Lets study in more detail each component of the oscilloscope. On digital scopes, there may be a pushbutton, but you may have to locate the options in a menu. How to rotate pdf files and merge using pdftk in linux. I did some hunting and managed to find the original service manual as a pdf, and started working down the troubleshooting chart. The price to pay is an attenuation of the signal that reaches the oscilloscope input3. The cathode ray oscilloscope introduction the following should give the student some familiarisation with the function and uses of the cathode ray oscilloscope c. Consider a simple sine wave electrical signal from some source as in fig.
An analog scope is an oscilloscope constructed with analog circuit. The oscilloscope places an image of the timevarying signal on the screen of a cathode ray tube crt allowing us to observe the shape of the signal and measure the voltage at di. It is very similar, but slightly simpler than the waterman. The deflection of the oscilloscope beam is proportional to the input voltage after ac or dc coupling. To connect a probe that uses a bnc connector, push and turn the probe connector until it slides on the oscilloscope channel input connector. Then switch on the instrument and afterward the device under test. Sound card oscilloscope pdf download free pdf books. Howard, wanted to send you a few pictures of the evolving project. The back side of the screen is treated with a coating that phosphoresces wherever the electron beam hits it. The oscilloscope is switched on by depress the onstby pushbutton before. If we can arrange things so that this sinusoidal voltage is applied. The purpose of this lab is to introduce students to the basic tools used by engineers and technicians in analyzing electronic equipment. Early oscilloscopes used cathode ray tubes crts as their display element hence. When trouble shooting a malfunctioning oscilloscope.
The electron beam creates a bright dot on the face of the cathode ray tube. Turn your old tv into an oscilloscope and try to avoid death. Hello, and welcome to my latest project turning a small crt monitor into a fully functional oscilloscope. Some waveforms combine the characteristics of sines, squares, steps, and. Example 7 on an accelerated electron see lesson 1 describes a portion of a cathode ray tube crt. Check that the device under test is switched off and connect the test leads to the test points.
The manual provided with your oscilloscope will give you. Feb 12, 2017 a cathode ray tube, or crt, is one of the earliest forms if not the earliest form of electronic display. All you need to do this macguyverstyle project is an old tv, some wire, a soldering gun, some rubberhandled pliers and a screwdriver. Energized the native oscilloscope circuit to illuminate the scope display grid. The crt clocktvscope is the result of efforts to develop a reasonably simple circuit that incorporates a few common and fun uses of an electrostatic crt. Y deflection block diagram of the crt the oscilloscope. Electronic circuits in the scope apply voltages to one set of deflection plates to sweep the. What the heck is a radiator plate in a crt based oscilloscope.