[Beginners] How to use oscilloscope

In this video, I would like to talk about the topic of how to use an oscilloscope.
If you are not sure whether or not to buy one, or if you have bought one but do not know how to use it, please refer to this video.
-Related Link
OWON Digital Oscilloscope SDS1022
amzn.to/3xN5ZyQ
-Self introduction
Hardware engineer
9 years experience of electronics
-SNS
Web : lab-b.jp
Twitter : / buonoatsushi
-Text
First, let me explain the basics of oscilloscopes.
An oscilloscope is a measuring instrument used to view changes in voltage over time at a given point. It consists of a probe to grab the point to be measured and a main unit to process the captured voltage and display it on a monitor. Testers are often used to view voltages, but the biggest difference between testers and probes is that testers are able to capture changes over time. Testers, in fact, only display averaged voltage values over time, so they cannot capture fast voltage changes. Oscilloscopes, on the other hand, can capture high-speed signals on the order of several ns for fast ones.
Therefore, oscilloscopes are used in all situations where time is involved, for example, to check the output value of a sensor over time, to check whether the signals to turn a motor are in the correct order, or to check whether the rise time of a signal is within a specified range.
To explain the principle, oscilloscopes and probes generally contain such a circuit, which, after reducing the voltage to 1/10 of the voltage to be measured, captures it into the CPU through analog-to-digital conversion and displays the waveforms. The reason why the voltage is reduced to 1/10 here is to minimize the effect on the measurement target. By putting a large resistor in the measurement system, the current flowing to the measurement target remains almost the same even when the probe is connected, so that accurate voltage values can be measured.
Next, let me explain the basics before using an oscilloscope.
Here, I would like to use an oscilloscope provided by a manufacturer called OWON. The basic functions and usage of other oscilloscopes are almost the same.
First, as for how to view the oscilloscope screen, the horizontal axis represents time and the vertical axis represents the magnitude of voltage. The rightmost horizontal axis is the most recent information, and time flows from right to left. The yellow and blue lines are the voltages for channel 1 and channel 2, respectively, and the lines here are the respective 0V standards. The numbers here represent the time per square and the voltage value per square.
The operating part of the oscilloscope is roughly divided into these two parts. The two main parts are used to adjust the length and position of the time axis here and the size and position of the voltage axis here.
The other important part is to adjust the position of this trigger. The trigger is the reference point at which the waveform should be displayed when the voltage is above or below a certain V value. Oscilloscopes cut off a certain portion of continuous time and display it, but if the cut-off width is short, the display will switch from one time to another at high speed if all the time is displayed, and the human eye will not be able to follow it very well. To use an analogy, it is like switching channels on a TV at high speed. In order to take the time to watch the program you want to watch, we generally set this trigger to take in the screen only when the voltage meets a certain criterion and ignore the rest. The trigger is a bit hard to understand, but it is a super important part of using the oscilloscope, so be sure to keep it in mind.
Next, let me explain the probes. Each probe has an alligator clip on the end like this, and the alligator clip is attached to GND, and the probe is used to pinch the point you want to measure in the circuit with the tip. What you must do before measurement is to adjust the probe to capture the voltage as accurately as possible. As explained earlier, oscilloscopes read the actual voltage at 1/10th of the actual voltage. However, if the frequency is high, the parasitic capacitor component that inevitably accompanies the probe will cause the voltage to become unbalanced, making it impossible to accurately measure the value. Therefore, by adjusting the value of the variable capacitor here, it can be reduced to approximately 1/10 of the original value at any frequency.
When adjusting the probe, first connect the GND wire to the bottom of this protrusion on the front of the oscilloscope and the probe to the top. Then, press the Autoset button. Then, the voltage and time axes are automatically adjusted so that the waveform fits on the screen. Since a pulse signal with an amplitude of 5 V and a frequency of 1 kHz is emitted from this protrusion, the waveform should normally display a beautiful, crisp waveform.

[@oppyoko]

オシロスコープは知っていましたが、実際の使い方等々に付いては全く知らない状態だったので、非常に参考になりました！！

[@BuonoTV]

よかったです！コメントありがとうございます👍

[@user-nr5qi1tv3e]

すげぇわかりやすい。プローブ、オシロスコープ、RCフィルタの回路図を貼ってくれるおかげでありえないくらい理解しやすい。いいねしておきます

[@BuonoTV]

いいねありがとうございます！はげみになります👍

[@user-sn3nq1hk5v]

結果的に自分の知りたいことはこの動画内には無かったのですが、文字起こしを掲載して頂いてたお陰で検索性や見通しが良くてとても助かりました。丁寧な動画づくりに感謝します。

[@BuonoTV]

そう言って頂けてうれしいです！🙏

[@RecycleMemo]

当時の職場に多くあったのは岩崎通信機さんのシンクロスコープ・・・なので今でもオシロスコープをシンクロスコープと言ってしまう・・・ 数十ナノ秒のパルス遅延の事象を見るためにアナログオシロのブラウン管に外光を遮断する筒を付けて観察してました。 使用していたオシロはテクトロさんと岩通さんでしたがブランウン管の表示は岩通さんがシャープで綺麗でした。

[@nekosan0]

プローブとオシロ内部回路を眺めたときの、オシロ内部側にある1MΩ抵抗に並列にしている20pFの容量って、実際に内部の回路に組み込まれているコンデンサのものなんでしょうかね？それとも、ADCの入力端子（ゲート）の容量なんでしょうかね？もしくは、それらや回路基板なんかの容量を全部合計した容量が「だいたいこのくらい」というものを指しているんでしょうかね？　なんとなく、少し大きめのコンデンサを意図的に並列にしておくことにより、回路やADCの入力端子容量なんかの誤差・ばらつきを、プローブのトリマコンデンサで吸収しやすく（ある程度のレンジに収めやすくする）ために、あえてコンデンサを並列につけているのかなぁ？と思えたのですが…。

[@BuonoTV]

質問ありがとうございます！ 自分も分からなかったので色々調べてみたら、以下のサイトが分かりやすかったのでシェアしときますね。 detail-infomation.com/oscilloscope-calibration/ 結論として、オシロ内部にある容量は実際に接続されているもので、トリマコンデンサとプローブ浮遊容量と合わせて、高周波時に大体電圧が1/10になるように調整できるようになっているようです（低周波時は抵抗のパスを通って1/10になる）。 さらっと書かれてますがこのあたりに測定器屋さんの工夫とかノウハウが詰まっていそうですね。

[@nekosan0]

サイトのご紹介ありがとうございます。ケーブル浮遊容量＋オシロプローブ入力容量とあるので、どうやらコンデンサを内蔵しているわけではなく、ケーブル自体とADCの入力容量（などの回路基板側の容量）を足したもののようですね。ありがとうございました。