A brief overview of the development history of oscilloscopes

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An oscilloscope is a widely used electronic testing instrument. He is able to convert electric signals that are invisible to the naked eye into visible images, making it easier for people to study the changes in various electrical phenomena. Some people think that a multimeter is enough to get by; why waste time and effort learning to use an oscilloscope? In short, times have changed. The complexity and operating frequency of modern electronic equipment systems are beyond comparison to those of old devices such as black-and-white televisions and radios. Learning to use an oscilloscope can definitely **reduce your repair workload and improve work efficiency. Moreover, the application of oscilloscopes is not limited to the electronics field. An oscilloscope can measure various phenomena when appropriate sensors are installed. Such as sensors for sound, mechanical pressure, pressure, light, or heat. Medical professionals can also use oscilloscopes to measure brain waves. Therefore, it is no exaggeration to say that an oscilloscope is a highly versatile electronic testing instrument. Today, we will take a brief look at the history of oscilloscopes. I. The history of hand-drawn waveform oscilloscopes dates back to the 1820s, when galvanometers were combined with mechanical plotting systems to manually record waveforms. The device consists of a special single-contact commutator mounted on the axis of the rotating rotor. The contact point can move around the rotor according to the precise degree indicator scale, and the output is displayed on a galvanometer, which is then manually plotted by technicians. Since this process is formed over thousands of wave cycles, it can only produce a very rough approximate waveform. II. Mechanical automatic waveform drawing: The first automatic oscilloscope used a galvanometer and a pen to capture waveforms on a continuously moving sheet of paper. Since the frequency of the waveform is relatively high compared to the slow reaction time with mechanical components, the waveform image is not drawn directly; instead, it is created over a period of time by combining many small segments of different waveforms. It will automatically charge and record the capacitor from the 100th wave, with each subsequent charging of the capacitor starting from a point slightly further along the wave. The measured values for such waveforms are still the average of hundreds of wave cycles, but they are more accurate than the previously hand-drawn waveforms. III. Analog Oscilloscope: An analog oscilloscope is primarily based on a cathode ray tube (CRT); the electron beam generated by it is directed at the phosphor coating on the screen through horizontal and vertical bias systems, thereby displaying the waveform. Cathode ray tube used in oscilloscopes: 1. Deflection voltage electrodes 2. Electron gun 3. Electron beam 4. Focusing coil 5. Screen coated with phosphor. In the 1940s, the development of radar and television required high-performance tools for waveform observation; Tektronix successfully developed a synchronous oscilloscope with a bandwidth of 10 MHz, which became the foundation for modern oscilloscopes. An oscilloscope with synchronous scanning function. To increase the bandwidth of an analog oscilloscope, it is necessary to advance the cathode ray tube, vertical amplification, and horizontal scanning all at once. To improve the bandwidth of a digital oscilloscope, it is sufficient to enhance the performance of the front-end A/D converter; no special requirements exist for the oscilloscope tube or the scanning circuit. In addition, digital oscilloscopes can make full use of memory, storage, and processing capabilities, as well as various triggering and pre-triggering functions. The 1980s saw the dominance of digital oscilloscopes, with many manufacturers ceasing to produce analog oscilloscopes; as a result, analog oscilloscopes gradually faded from use. IV. Digital Oscilloscopes Digital oscilloscopes are high-performance oscillators created through a range of technologies such as data acquisition, A/D conversion, and software programming. Digital oscilloscopes generally support multi-level menus, offering users a variety of options and analysis functions. There are also some oscilloscopes that provide storage, enabling the saving and processing of waveforms. For oscilloscopes with a bandwidth of several hundred megahertz, domestic brands now offer performance that can compete with that of foreign brands, along with a clear advantage in terms of cost-performance ratio. Digital oscilloscopes have most of the basic functions of analog oscilloscopes. For example, the function of displaying basic waveforms, the x-Y operating mode, basic triggering methods, etc. It also includes things such as trigger delay, the coupling method of the input signal, afterglow adjustment, and calibration of the signal source output. Digital oscilloscopes offer a variety of additional useful functions compared to analog oscilloscopes. The most common ones include automatic range selection, automatic measurement of various parameters, storage of waveforms and setting conditions, interface buses, display of average-level curve fitting (interpolation method), high-pass and low-pass filtering for bandwidth, trigger operation modes and selection of trigger conditions, as well as cursor measurement. V. Touchscreen Oscilloscopes: In today’s era, humanity is undergoing a digital revolution, with emerging technologies such as 5G, the Internet of Things, big data, cloud computing, and artificial intelligence continuing to evolve. Oscilloscopes are also going through a revolution. The touch-based operation of smartphones has proven to be more efficient compared to traditional button-based systems. Oscilloscope manufacturers are also considering applying touch technology to oscilloscopes, as a replacement for the traditional button and knob control methods. The obsolescence of existing technical equipment and the slow progress in improving current technologies are causing great headaches for engineers. Touchscreen oscilloscopes offer engineers a completely new way of working, **improving their efficiency. This entirely new way of interaction allows engineers to more quickly identify issues within the overall product design. They can also use test results for analysis in order to detect and resolve problems, without having to worry about how to operate the oscilloscope.