Other Basic Electronics, Multimeters, & Oscilloscopes

This thread is about basic electrical, electronics, Multimeters, and Oscilloscopes. It is an outcome of interest that various members have expressed about these subjects.

@Janger , @Johnwa , and @kevin.decelles have all recently obtained a starter Oscilloscope so I think the timing is good for a thread like this.

The primary resource will be a book (available on Amazon in paper or kindle) called Electronics for Dummies by Kathleen Shamieh. The book isn't a requirement, but it always helps to have a reference of some kind to facilitate discussion. Other references might get added as the thread progresses.

I'm not picturing this thread as a course, just a good place to ask questions, find answers, and share knowledge and experience about basic electrical knowledge and testing.

As always, a good time and lots of great jokes are expected!


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Settings suggestions? Let's assume I'm trying to catch a 7 Volt, 3 Hz square wave for about 180 RPM. About 2V/cm & 200 mS/cm?

I'd use the external trigger input, connect that to the same point as your regular input with an alligator clip, and try setting the sensitivity to auto. You shouldn't need a high frequency input nor trigger filtering for this job. I've been known to just push buttons too.... LOL!

When you speak of a small RC circuit are you speaking of a series resistor (value?) with a small (a few pf) cap between the signal side of the resistor and ground?

Given how low the frequency is, I was thinking two 50k resistors in series with the signal input to the device or the scope and a few microfarads in between them to ground. You will know when you see the signal whether that is too much or too little. I just want to get rid of the high frequency noise - if any. The resistor on the scope side isn't required, but it usually helps maintain a better signal too. You are just making what is frequently called a "low pass filter". You can find formulas on the web, but I usually just play with it till I see what I want.

I understand the reed is a mechanical switch subject to wear but I’m scratching my head on this one because that’s what most of the treadmills use for their Tach input. Designed to price point? Maybe they aren’t designed to get that much use over their lifetime or maybe it’s a planned service revenue stream.;)

I'm just not a fan of reed switches. Their quality can vary all over the map.

Base on my limited experience you do indeed want to mock up your installation before spending any time designing and making in-machine mounts. From what I hear, it also pays to mount the display right side up for the test.;)

I guess I'm just used to that kind of stuff working first crack. My confidence is probably misplaced.

I can’t guarantee that a genuine Noga mount will work, I used an imitation Nauga from PA, I’m not sure that stood out in my description. :p

It didn't. I honestly thought it was a typo! LOL!

I prolly won't use a Noga either. Anyone of my mounts should work and all are easier than fabbing a custom bracket.