New Here! - Page 1
Forum section: electronics / general

author: SomeGuy
author_rank: Contributor
timestamp: January 22, 2022, 01:51:37 am
content: Hey everyone, new here but have been reading for a little while. I've started working on an RC project (building a wheeled RC tank from scratch) and was researching some electronics equipment and came across this place, impressed with just how much information there is here. Helped me decide on getting a Siglent SPD3303X-E bench power supply and Siglent SDS1104X-E scope.The bench supply was pretty much a no brainer that I needed one, lots of low voltage DC equipment to power up and test and a lot easier/less risky than plugging in big battery packs.The scope I ended up getting because I ran into some issues with the RC receiver and motor drivers not talking nice to each other. Helped me understand what was going on with them.Anyway, I hope this isn't against the rules, but I am documenting the build on YouTube if you want to check it out:https://www.youtube.com/channel/UCBwA36YGRBRyjJd-ZZM7qLwI have part 1 up now, and explains that RC/driver problem I ran into. I'll probably get part 2 up this weekend as my new motor drivers arrived today. Also a couple "shorts" (less than 1 minute videos) of unboxing of both pieces of Siglent gear I just got, nowhere near as good as some of the deep dive videos the guys here have done, but I'm also new to this YouTube thing...I'm actually learning electronics, YouTube, and machining (recently got a metal lathe) all at once for this projectAnyway, nice to be here and I'm sure I'll be using this place for more research as I work through this project.Cheers!

author: jpanhalt
author_rank: Super Contributor
timestamp: January 22, 2022, 10:55:49 am
content: I don't know whether posting a link to your blog is against the rules. Others have done that here. However, your only other post on this forum is also a link to your blog. That type of double posting is frowned upon, but its not fatal so far as I know.

author: tooki
author_rank: Super Contributor
timestamp: January 22, 2022, 10:59:13 am
content: I think it’s ok as long as it’s not posted for commercial/advertising purposes, which does require moderator approval.

author: SomeGuy
author_rank: Contributor
timestamp: January 22, 2022, 04:04:18 pm
content: Quote from: jpanhalt on January 22, 2022, 10:55:49 amI realized the other forum was there after I made this post.Honestly, I've just been doing more reading here than anything. Most of the topics are a bit over my head so I don't have a lot to add at this point.

author: SomeGuy
author_rank: Contributor
timestamp: March 03, 2022, 02:58:58 pm
content: Part 3 of the RC Tank Build is finally up, has taken a while getting parts and learning how to use a lathe, but none the less it's here:https://youtu.be/pPY6EV8jBKEAlso, seems I didn't share Part 2...but this has the Siglent scope and power supply I picked up from reading stuff here on this forum...used it to figure out some of the RC signal issueshttps://youtu.be/L_xpE2DQ55Q

author: RJSV
author_rank: Super Contributor
timestamp: March 06, 2022, 01:34:48 am
content: WELCOME !There are PLENTY of us, out there eager to read some (well written) LATHE processes, for fab.A bit of background info, maybe the good deal, you scored, all of that summarized carefully is nice.When I mention a consumer product, I often just say things like: "...purchased at nearby Drugstore Toy aisle."(See my R/C car, with Robot Dog Driver...attached photo).

author: SomeGuy
author_rank: Contributor
timestamp: March 06, 2022, 02:02:52 am
content: Quote from: RJHayward on March 06, 2022, 01:34:48 amHonestly, I'm a complete machinist noobI have never used a lathe before this, though I've read/watched/researched a bunch before I just jumped in doing it so I had a fair idea of how it works. This is as much a learning experience for me as is the electronics of the RC and the youtube stuff too. Always trying to learn something new, just bit off a few more at once this time

author: RJSV
author_rank: Super Contributor
timestamp: March 06, 2022, 05:10:47 am
content: You can always send PM, apologies if it takes, couple days, or whatever.Yeah:. Send PM, with any questions, I'll try(To send, just find the little cartoons bubble, next to user name)-Rick B.

author: EEVblog
author_rank: Unknown
timestamp: March 06, 2022, 07:50:03 am
content: Quote from: SomeGuy on January 22, 2022, 04:04:18 pmWe have a Projects section for postign your projects and updates etc, and a Other Blogs section for technical channels to post their latest video etc. If videos are related to one project then I'd say the Projects section is best.

author: tautech
author_rank: Super Contributor
timestamp: March 06, 2022, 08:16:30 am
content: Quote from: SomeGuy on January 22, 2022, 01:51:37 amFYISPD3303X-E have a susceptibility when powering motors that provide regenerative braking that might exceed their reverse voltage protection so best advice is to install a beefy series diode to protect the PSU.It's not a common problem and only one unit I'm aware of has suffered in this way but this is something the novice can easily overlook.

author: amabelgokey
author_rank: Newbie
timestamp: March 06, 2022, 12:47:11 pm
content: I think it's OK only if you don't do it as an open advertisement.

author: SomeGuy
author_rank: Contributor
timestamp: March 06, 2022, 04:49:38 pm
content: Quote from: tautech on March 06, 2022, 08:16:30 amI haven't used the PSU to power the actual motors for this project and definitely won't. The motor drivers I'm using specifically say to use a battery as well.

author: RJSV
author_rank: Super Contributor
timestamp: March 06, 2022, 08:16:02 pm
content: Hello someguy:Hope folks here are helping!One good rule, (IMO), for criticism, is that NOW, one is obligated to see that person benefit.So, took a second, before I start my own day, to illustrate the response (from Kleinstein).Please see diagram, of basic low resistance in the supply line. SHUNTS, I think of more like less than one tenth (ohm)...but that's just me.How about, we look at just TWO cases, as you've outlined.Suppose the uP sleep mode is at 200 uAmps, and suppose running at ave. 85 mA...That's, maybe your best quick guess, before starting anything. Grab your 0.58 ohm and do first glance, at the PC Board waveform, maybe some noise on that but the PC circuit generally has cap. and then regulator, so that input point shouldn't be wildly noisey (?)So, a half-ohm, try expecting a drop of:At 85 mA, that's an easy 85/2 = about 43 mVNotice that has fairly good resolution...(Don't get all hung up on wanting an A to D converter show 'full scale' for best accuracy. I believe it's easy to get into false 'overconfidence', that lots of digits equates to 'lots of accuracy...On the low end, that nominal 200 uAmps load current brings a (less accurate) voltage reading, of 100 uV.My (Velleman) DMM appears to only show the first digit, on the '100 mV' scale. (The low 00.1 mA is what you see on meter display.)But you can see, the point Kleinstein had, about not putting in too much supply drop, or the usual regulator does not get sufficient input voltage. Here, you get something like a tenth volt drop...less than what normal battery use involves.(More response later)

author: SomeGuy
author_rank: Contributor
timestamp: March 07, 2022, 05:48:21 am
content: Quote from: RJHayward on March 06, 2022, 08:16:02 pmI have literally no idea what you just said

author: RJSV
author_rank: Super Contributor
timestamp: March 07, 2022, 03:12:47 pm
content: MY BAD, sorry.That was a misfired post, was supposed to send to the fellow doing processor current sensing...sorrysorry

author: SomeGuy
author_rank: Contributor
timestamp: March 07, 2022, 03:26:25 pm
content: Quote from: RJHayward on March 07, 2022, 03:12:47 pmLOL ok, no worries. I was so confused, couldn't make sense of any of that in relation to anything I had posted, and just some of the stuff was generally over my head.

author: RJSV
author_rank: Super Contributor
timestamp: March 07, 2022, 05:13:47 pm
content: ..thanks for overlooking,That other subject, was involving the lowest ranges, in a typ DMM.Just that measuring low current, it's better, somewhat, to stick a half-ohm resistor in series, and read the voltage, but meters generally only go down to, like 00.1 on the mV scale, so that 100 uV you see in the read out is getting rock bottom...Rick.

author: SomeGuy
author_rank: Contributor
timestamp: March 07, 2022, 06:52:31 pm
content: Quote from: RJHayward on March 07, 2022, 05:13:47 pmInteresting, I guess that makes sense (I know you can read voltage across resistor to get current at least lol). Also, my Fluke 287 seems to go lower than that on scale?

author: SomeGuy
author_rank: Contributor
timestamp: March 07, 2022, 06:56:02 pm
content: Quote from: SomeGuy on March 07, 2022, 06:52:31 pmOh, and the only reason I have a 287 is because when I went to buy a good meter, I found one new for cheaper than a 87V

author: SomeGuy
author_rank: Contributor
timestamp: April 01, 2022, 11:22:48 pm
content: Just posted up Part 4 of the build, it's coming together, starting to actually take shapehttps://youtu.be/xCvjLrztIIU