Learning the Art of Electronics - 1L.4 The diode - Page 1
Forum section: electronics / beginners

author: ultrageranium
author_rank: Contributor
timestamp: June 12, 2020, 02:41:16 pm
content: Hi everyone,First post here, and on a journey to go through both AoE and its Lab Course addition. So far so good, but today I encountered my first moment of complete confusion with section "1L.4 The diode" from the Lab Course (p. 29-30).By looking at how the circuit behaves, the current going through the ammeter goes beyond 1mA, and the scale of the empty plots (Figure 1L.8 ) also implies this could potentially go up to 10mA. However so far in the previous lab experiments and the parts needed, the only ammeter mentioned is one with a 0-1mA range. So is it that this experiment is meant to be done with a better equipped lab with a 10mA available, or am I overlooking something?Thanks!PS: what's the best practice for such questions and future ones I may have? I bump my thread with a new question? I make one post per question?

author: ultrageranium
author_rank: Contributor
timestamp: June 13, 2020, 11:38:00 pm
content: Replying to my future similar self who may be wandering desperately as well: I just went ahead and turned the 1mA ammeter into a 10mA with the adequate shunt resistor. As it turns out, soon enough a 20mA and 50mA range were also needed (it's more handy at least). It's still completely unclear to me if that's what was supposed to be done, or if your own lab is supposed to have several kind of ammeters available, but at least I could move on!

author: gfmucci
author_rank: Regular Contributor
timestamp: June 14, 2020, 01:50:05 am
content: My technique for asking questions, and I haven't been banned from the board yet, is to ask the question in different ways, with different leading words in the title, if you don't get any response that answers your question unambiguously. Don't give up asking!

author: gcewing
author_rank: Regular Contributor
timestamp: June 14, 2020, 05:08:52 am
content: Quote from: ultrageranium on June 13, 2020, 11:38:00 pmIt's probably expected that most people doing the experiment will have a multimeter with a variety of current ranges available. It's a basic piece of equipment that anyone pursuing electronics as a hobby or career should get.

author: gcewing
author_rank: Regular Contributor
timestamp: June 14, 2020, 05:13:01 am
content: Quote from: ultrageranium on June 12, 2020, 02:41:16 pmStart a new thread for each new question. Only add to an existing thread if it's something directly related to it.

author: james_s
author_rank: Super Contributor
timestamp: June 14, 2020, 06:49:01 am
content: Only one day has passed since the original question was asked, nobody here is a professional support person, sometimes you just have to be patient. Ask a question, then wait a few days before following up or asking it again. Also make sure you provide enough information so that people can figure out what you're asking, I don't have the book myself so I can't look up the exercise.You definitely need a multimeter, a basic one costs less than the book, there's no excuse to not have one and you will not get anywhere in electronics without it. My multimeter is the most used tool I own, I use it nearly every single day despite the fact that my day job has nothing to do with hardware anymore.

author: ultrageranium
author_rank: Contributor
timestamp: June 14, 2020, 10:42:19 am
content: Quote from: gfmucci on June 14, 2020, 01:50:05 amQuote from: gcewing on June 14, 2020, 05:13:01 amGood tips, thanks!

author: ultrageranium
author_rank: Contributor
timestamp: June 14, 2020, 10:55:12 am
content: Quote from: gcewing on June 14, 2020, 05:08:52 amQuote from: james_s on June 14, 2020, 06:49:01 amYes, of course! I should have added the full text to avoid confusion! Here it is attached. I already have a DVM, but as you can see this experiment requires simultaneous voltage and current samples with both a DVM and an analogue ammeter. So far in the book, and the list of equipment to follow the course, there is only mention of a 1mA full scale ammeter (I have one) which is not enough for this particular case. It was unclear to me if I was supposed to first extend the range of the 1mA ammeter or if they take it for granted that the reader has a whole range of analogue ammeters at their disposal. I ended using a shunt resistor to extend the range of my ammeter, and the results I get make complete sense, so I think that was an acceptable way to proceed.It was a bit confusing because the writing so far tends to be very explicit when it comes to give hints to the reader.