I made this!   - Page 1
Forum section: electronics / beginners

author: jewelie
author_rank: Regular Contributor
timestamp: January 23, 2018, 04:50:18 am
content: Hi all.Just a quick pride post.Yesterday I made this! Squee!Finally doing the things on my to do list that I got the parts for a year or two ago.It went faultlessly from LTspice to pencil and paper stripboard planning to soldering... was only when I tried to put holes in the board for the big terminals that a mini disaster happened and the board split, but worked around it.Cutting the holes in the box is still the hardest part of all this for my cos it's bit I'm newest too. Dremel still scares me a bit and my better half was sleeping, so did it by hand.Stripboard planning was interesting, took a while before I got a layout that just clicked and took a minimum of space and just fitted on a bit of spare board I had.Strange choice for battery I know, but the sweet spot for this 2.5V ref is 10V (around 9V to 12V seems accurate enough) and it also meant I could use a small cheap project box I had.Started with an 2 x NPN circuit for battery LEDs from the web then reworked it for 2 x PNP (because the bi colour LED was common cathode) and adjusted the values to minimise current usage whilst balancing LED brightness and green/red switch over point. 6mA in use, which should be fine with this battery for occasional use.Need to meet up with some makers at some point to get it trimmed as accurately as I can get it. Plus I need more electronicy friends really anyway, else I'm gong to end up just posting pictures of what I make on the Internet and boring people instead.JulieX

author: daybyter
author_rank: Frequent Contributor
timestamp: January 23, 2018, 05:09:09 am
content: Congrats!

author: jewelie
author_rank: Regular Contributor
timestamp: January 23, 2018, 06:51:45 am
content: In case it's of any use to anyone else. Schematic, simulation plot and LTspice file.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: January 23, 2018, 01:22:40 pm
content: Nice work!There are a couple of ways to make nice holes in plastic boxes. For round holes in thin plastic, a "step-bit" in your drill works very well, without splitting.For odd-shaped holes ... use your soldering iron to melt the hole! And an xacto knife to trim the molten edges clean. Experiment to find the right heat setting, go slow, clean and re-tin the tip afterwards.https://images-na.ssl-images-amazon.com/images/I/51lyO-rmDuL._SL500_AC_SS350_.jpg

author: jewelie
author_rank: Regular Contributor
timestamp: January 23, 2018, 01:34:49 pm
content: Quote from: alsetalokin4017 on January 23, 2018, 01:22:40 pmMaking roundvholes isn't too bad. I've got some wood drill bits that generally do a nice job. Odd shaped holes I've struggled with. The dremel plus ebay cheap "diamond" burrs worked out okayish for the last box I did, although that also melted the plastic which ended up attached to the burr (oops.) For the box in the picture, for the switch, after drilling an initial hole I just expanded it by hand using needle files. Took ages but was neat. Never thought of using the iron! Nice idea, when my current tip is deceased I'll save that for using for such purposes! Thanks.PS Shameful admission for this forum: I'm still on my original 25W and 12.5W plain Antex irons from 15-20 years ago. I know the posh temperature control ones are better, but I'm so used to these irons. I have changed the tips though, lol.J

author: jewelie
author_rank: Regular Contributor
timestamp: January 23, 2018, 01:36:53 pm
content: Quote from: alsetalokin4017 on January 23, 2018, 01:22:40 pmPS It wasn't the box that split, it was the stripboard!

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 23, 2018, 01:46:32 pm
content: Quote from: alsetalokin4017 on January 23, 2018, 01:22:40 pmLast year, I finally decided that the solution is a 3D-printer. Holes, curves, angles, size...no problem! That revolutionized all of my hobby projects. I take adventures that I never would have attempted before. Yeah, not cheap...but loads of fun!!

author: kalel
author_rank: Frequent Contributor
timestamp: January 23, 2018, 01:53:09 pm
content: Quote from: Wimberleytech on January 23, 2018, 01:46:32 pmI guess it would be a good opportunity to learn some mechanics basics, as you could make gears, limbs, joints, and work with servos and such. Or even experiment with your own fan blade shapes, to see if one seems more effective than another. However, it's still not really not affordable for everyone.Maybe one day.

author: Kalvin
author_rank: Super Contributor
timestamp: January 23, 2018, 02:12:02 pm
content: 6 mA for the LED is quite a lot to sacrifice as the reference consumes only 1 - 1.5 mA. If you want to extend the battery life 4X, add a momentary push button for the battery test and modify the circuit so that it will light the green LED when the button is being pressed. It is ok to keep the red LED functionality as it is now ie. red LED is being lit on low battery voltage, as the red LED will be lit only after the battery has already gone bad. Just my 2c.

author: phil from seattle
author_rank: Super Contributor
timestamp: January 23, 2018, 03:44:15 pm
content: It is very satisfying to make something like this and put a "bow" on it. Too many boards get left bare.Some points:Use an old soldering iron to melt plastic. I picked up a crappy, used radio shack one for that purpose at a thrift store. Don't use your "good" one for plastic.Get a nibbler. Good for rectangular holes in thin material - plastic, metal, perf board, fr4.+10 to the 3D printer. Makes it a lot easier to put a nice finish on your projects. You can wow the non-techies in your house by printing up replacement parts for broken plastic items. That stopped my wife stopped complaining about my hobbies.And to up your game, learn PCB layout (KiCad or what ever) and get real PCBs made. It's cheap and fast these days.

author: jewelie
author_rank: Regular Contributor
timestamp: January 23, 2018, 04:21:17 pm
content: Quote from: Kalvin on January 23, 2018, 02:12:02 pmThe 6mA is total for the circuit, worst case. I REALLY like your idea of a monetary push button for the green to minimize normal use current, although I can't easily remove the board now to mod it.

author: jewelie
author_rank: Regular Contributor
timestamp: January 23, 2018, 04:23:46 pm
content: Quote from: Wimberleytech on January 23, 2018, 01:46:32 pmFortunately I'd have nowhere to put such a thing so I don't pine for one. There's a big local makers group near me that have one though. I need to go meet with them at some point.

author: james_s
author_rank: Super Contributor
timestamp: January 23, 2018, 07:34:24 pm
content: For cutting holes in boxes and panels I have a few favorite tools. One is a step drill, few people seem to know these exist but they're wonderful for drilling holes in sheetmetal and plastic. They look like a cone with ridges, they can be expensive but the cheap ones I got from Harbor Freight (pretty similar to Machine Mart in the UK) work fine.The other really handy tool for thin materials is a nibbler, these are great for cutting square/rectangular openings.Lastly a set of files, it's handy to have flat and round profiles in various widths, they work on most materials but are especially quick on plastic. Drill a hole big enough to get the file in and then file it out to size.I typically use Inkscape to draw a template, then stick that to the surface with double sided tape and do all the drilling, cutting and filing, that makes it relatively easy to get everything all nice and straight. Then if you want a really fancy looking panel, print out an overlay, laminate it and glue it on.

author: cowasaki
author_rank: Frequent Contributor
timestamp: January 25, 2018, 10:57:41 am
content: Quote from: alsetalokin4017 on January 23, 2018, 01:22:40 pmJust to correct your mistake.... usesomebody else'ssoldering iron to melt the hole! ....

author: Old Printer
author_rank: Frequent Contributor
timestamp: January 25, 2018, 01:44:37 pm
content: Quote from: cowasaki on January 25, 2018, 10:57:41 amReallyTo Jewelie: Very nice project, nicely finished! Your choice of multimeter says funding is available, or at least wasI treated myself to a Hakko 888 last year and put my trusty Antex in the drawer. Major upgrade, just watch for counterfits so buy from an authorized dealer. Wish Hakko still made the analog version

author: jewelie
author_rank: Regular Contributor
timestamp: January 25, 2018, 02:12:40 pm
content: Quote from: Old Printer on January 25, 2018, 01:44:37 pmThank you.Regarding the meter: I was very lucky, I was given it actually! It's the first version and extremely old (I gather the original owner got it when it had just been released and barely used the best features.) It was pretty crusty, to say the least, but I gave it a serious cleaning and repaired a few bits that were practical to do.There's a few minor issues but with luck it'll have a few more years of use. And yes, they're as nice as people make them out to be.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: January 25, 2018, 05:11:56 pm
content: Quote from: jewelie on January 25, 2018, 02:12:40 pmNicely done project! Congratulations, however, condolences to 'your better half' now since you have the bug. You will spend many hours on this beautiful hobby away from your 'better half' and that can be a problem.In regards to the 87, I lusted after the 87 for many years, couldn't afford the price when I was an electrician in the early '80s and settled for the 77, which served me very well in my craft. I still have my "crusty" 77 now, but it is the worse for wear and no longer works. I would like to get it to functioning again, but I now have 5 meters (DMMs) so it is low on priority list.Kudos for first project done! The problems that you described are typical and there has been a few members here wanting a mechanical engineering perm thread, we will see how that goes.https://www.eevblog.com/forum/chat/eevblog-like-forum-for-mechanical-engineering/msg1409655/?topicseen#newEDIT: Added link to thread.

author: james_s
author_rank: Super Contributor
timestamp: January 25, 2018, 06:02:12 pm
content: I love my Fluke 87, it's nearly perfect. The only complaint I have is that for some mysterious reason it lacks the extremely handy audible diode test my old Fluke 79 had, I really miss that feature. It's so useful that it's hard to believe it's not standard on all DMMs.

author: kalel
author_rank: Frequent Contributor
timestamp: January 25, 2018, 06:56:59 pm
content: Quote from: james_s on January 25, 2018, 06:02:12 pmHow does that work? I only know of audible continuity testers so far, but I do not own any expensive meters.

author: james_s
author_rank: Super Contributor
timestamp: January 25, 2018, 07:55:02 pm
content: Quote from: kalel on January 25, 2018, 06:56:59 pmA good diode or transistor junction makes a short "beep!" then silence while a shorted junction makes a solid "beeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeep" as long as the probes are on it. This allows you to easily test diodes and transistors without taking your eyes off to read the forward drop. Once you use it for a while it's hard to go back.