Electronic ignorance

I can't recall just how many Practical Wireless and other similar sources of designs that I have built that didn't work. There were a number of them. Part down to my source of components and also in part down to the designs. Wireless World designs had a habit of working what ever active bits were used within reason. The signs of a good design.

Nah what I actually meant was start with bipolar transistor design. Get the various types of functions that can be done with these and it's doubtful more modern items will be a problem.

If people want to do this though they ideally do need some gear. Oscilloscope, function generator and a dmm. These things needn't cost a lot of money. eg

**LINK**

Thandar and Black Star function generators crop up on ebay and are ok. Picoscope make USB scopes that work but probably cost more than the above.

An alternative route is the virtual one I mentioned earlier.

Books - I did mention these

**LINK**

Were maths is involved they do include plenty of worked examples. New ones are cheap too but there will always be plenty of used one about as students find them rather useful.

John

-

If you want to understand simple electronics, Practical Wireless is good. Everyday Practical Electronics is too, and they produce "Teach Ins" on CD covering various aspects of electronics. PW is mostly amateur radio, but the same principles apply, and EPE is mostly microprocessors, which seems an overcomplicated response, but, I was brought up on valves, and regarded transistors with suspicion for many years.

If you want to build projects that work, the RSGB RadCom, again amateur radio, publishes work of a high standard, is peer reviewed and has access to real experts in the field, inc. a contact point with the IET.

Maplins sell good guides to electronics, depending on your interest, and the radio control magazines and associated model engineering societies like the Gauge 1, Gauge 3 and 2 1/2 inch gauge society cover the subject at times.

Geoff

From what I have seen lots of sources get over complicated and don't deal with reasonable approximations such as the outline of a simple transistor amp I outlined. The art of electronics mentions exactly the same arrangement and also adds what I thought of adding but needed to do something else - the effective input and output impedance ( resistance ).

Those are important because once something else is hooked up to them they will have an effect and it's back to Kirchoff etc again.

On the other hand many sources on information on subjects like this will analyse the circuit to death in any number of ways using any number of the active parts characteristics. This is the sort of thing some one might try later. However don't be surprised if it doesn't produce better results. Some of it such as extensive ac analysis can identify certain possible problems and can involve what for some may be rather bizarre techniques, complex numbers, transforms, dirac pulses and all sorts of things. Often these things will be put over as if they are a complete cure for every problem. Sadly they are not.

Dirac is one of my hero's because he came up with the idea of using a dirac pulse for analysis. Like most good ideas it's incredibly simple - in principle. Using it is a bit hairy though.

John

-

Steve posted a link to an online tool in his post 1/07/2016 11:52:02

As far as I can see it has not prompted a single response, perhaps no body could be bothered to take a look?

I did, it certainly appears to be the best example of a simple simulator I have ever seen. It took me about 3 or 4 mins to get it doing interesting stuff. It might not simulate a bulb, battery and switch (it might, I never tried?) but it is very easy to use and has building blocks that are easy to edit. It shows flows (voltage/power etc) as moving dots that change in intensity relative to each other and is very interactive. You do have to have a grasp of schematic diagrams but that is par for anything in electrics/electronics.

Take a look and forget about what constitutes beginners or advanced, this shows you visually what is occurring, just like engineers like it!

Mark

It depend Rod how basic you want you information. However, there are four basic articles on my website being, Direct Current, Alternating Current, Electronics and Electrical motors. You will find the four listed on my website index here.

Harold

The one called Electronic Work Bench I linked to it pretty intuitive. I'm assuming it's the same as the one I have used. Different types of parts can be hooked up in the usual schematic fashion and following that it can actually be powered up and run. Signal generators, oscilloscopes and what ever can also be connected to it to actually see what is going on - just as people would generally do when working on electronics. I'd guess that the latest version is far more complicated to use as the simplicity of the older one was not that attractive to many electronics engineers.

I used it to design a metal detector once. Built the circuit and found that the amplitude of the oscillations was wrong by a rather odd factor so just did it again accounting for that. The problem may have been me, the package or a real implementation having factors that the simulation couldn't account for. Probably the stuff I wound the coil on. I also used it for a few other things. Seems fine to me.

John

-

Rather than assume (always a risky choice), why not try looking, then you would know how they compare..... it should take about the same time as it takes to type a response on here.

It is nothing like conventional simulators and at the same time very similar in operation, the graphical presentation is unique I think?

Mark

Just in case anyone missed it, the "Practical Wireless Circuits" that I referred to (tongue-in-cheek) earlier is a 1931 publication dealing with valve circuits. I still have my copy after (thankfully) not throwing it out half a century ago.

(I also still have both volumes of the "Practical Mechanics How To Make It Book" which actually still have some relevance - iirc there is a rather nice harmonograph build in one of those. Might dig it out.)

Bandersnatch, I have a small collection of books of this nature. Inc. one on how wonderful the new material called 'Radium' is! One on photography from the late 1890s, how to make your own 'Televisor' etc.

Geoff

Bandersnatch- re -red neg. cable- van is corsa, about 10 yrs. old, so modern. Wiring and battery are original. I only found out 'cos I'd flattened the battery and wanted to check the voltage after charging. Battery still good, so not bad for 10 yrs. My fault really, when I took off the plastic cover it was clear that both cables were red and clearly marked + & --. Lesson learnt.

It's a windows package and while it part works on Linux and looks much like the version i have used I can't actually use it. It's very similar to the web based one you mentioned ie this one

**LINK**

That shows something I did with it out of curiosity. There are links that can lead to a stand alone java version of it about on the site as well.

The main difference between that and EWB is it doesn't use models of actual parts. In other words rather than just pick transistor pick the type eg BC108 or etc.

John

-

Edited By Ajohnw on 01/08/2016 10:55:07

My favourite circuit simulation s/w is SIMetrix / SIMPLIS. It's actually British and has been around for a few years now. The free version supports up to 140 nodes which is pretty useful. There are quite a few compts in the std library including controllers, opamps, FETs etc. There are tutorials, videos etc on the website to get you going as well as plenty of examples that you can simply run and play with, some of them pretty complex.

There is also LTSpice which is used by many professionals. Amongst its advantages are the fact it is free but also it supports models of industry standard components such as active devices, ICs (such as PSU controllers and opamps) etc. Obviously it helps LT to sell their components but it's not restricted to just their products. Although it's based on SPICE, it's got a modern graphical GUI and is fairly simple to use. It's also a simple means of drawing up a schematic if you want to sketch out a circuit to illustrate a concept.

Murray

Yes, Practical Wireless used to publish some really excellent articles(!)

Edited By Muzzer on 01/08/2016 11:28:38

Rod, I'm not sure all this is helping you much. I suppose the question is, what do you want to achieve? Do you want to be able to design your own electronic circuits at component level, or to be able to wire up ready-built modules and troubleshoot common problems with them? If the former, you could try H&H, but if the latter you would just find it baffling and probably unhelpful.

To illustrate what I mean, I've been in electronics all my life and designed things for a living so wouldn't have any fears about designing most things, but in the past couple of years I've built the control electronics for 2 CNC machines and a dividing head, in all 3 cases buying things like stepper drivers, breakout boards, power supplies and so on. There has been little electronics design as such in any of them (but I guess the experience of 50 years counted when a few problems emerged that needed debugging).

So if you're building the electronics for CNC tools or 3D printers you need to know about how the off the shelf modules work as black boxes but you don't need to know much about what goes on inside or how to design them.

I would say to the OP, how far do you want/need to go with understanding electronics?

You mention struggling to commission a 3D printer - depending on what set of electronics you used, this can be anything from a set of modules (Arduino Mega, RAMPS shield, StepStick/Pololu stepper drivers), an all in one board (Azteeg or Beagle Bone) or a solder it yourself controller, again with StepStick/Pololu drivers (Sanguinololu, etc). whichever route you take, they mainly achieve the same thing - they provide a microcontroller platform on which to run some firmware (Sprinter, Repetier, etc) which in turn needs a few dozen parameters setting in order that it works correctly with your printer and steppers.

All that is in addition to configuring the mechanical printer for squareness, minimal backlash, an accurate origin and being able to traverse your bed accurately such that the nozzle is the same distance above it at all points in a given horizontal plane.

There is very little electronics knowledge required - from the moment you have plugged all of the modules together and wired up the motors and power supply, the electronics side is done and dusted.

Some understanding is required with regards what each of the firmware parameters do (even if you use a known checklist and only ever set them once) and how to upload that firmware, and then some trial and error with regards understanding what difference the various printer settings can have before you find some that are optimal for your printer.

Just trying to clarify what the OP is actually after and whether or not they really need to understand electronics, transistors, op-amps, etc, etc, for what they are trying to achieve, or if they were simply a little overwhelmed by whole end to end process of commissioning the 3D printer, most of which actually has very little to do with electronics itself.

If the wish is to move onto making other projects from scratch, then there is a wealth of information provided by others above in this thread.

John, I never heard of a Dirac pulse before, although I knew who he was. Now, having read it up on Wikipedia, my head is spinning, but a picture is worth a thousand words. Just as my Geometry teacher said, "a line has length but no thickness," a Dirac pulse is one occupying zero time with a 100% energy content. Simples! Real life is not so simple though. Gosh, the things I learn in Model Engineering!

Sorry Gordon, you lost me. Are you sure you replied to the right person/thread?

Ooh .... jogged a memory there, Geoff. I used to have an old book with an article about constructing a flying-spot transmitter and receiver. Wonder where that went ..... would be fun to build in modern guise.

There is a very clear explanation of why it is used in electronics here Geoff.

**LINK**

As daft as it sounds it simplifies things. I think it's use is demonstrated in one of the Schaum's books

You might find more by looking around at Laplace transforms such as this one which probably  wont help but does indicate the need for partial fractions.

http://people.seas.harvard.edu/~jones/es154/lectures/lecture_0/Laplace/laplace.html%20

No I don't carry that lot about in my head but have used it once or twice.

John

-

Edited By Ajohnw on 01/08/2016 17:53:51

I checked it out last night Mark and will be playing with it again later. I had no trouble getting an oscillator going. It seems to be a pretty good way of trying circuits without actually building them, and you don't have to be a genius to use it. Nor do you have to install anything.

Thanks to Steve for highlighting it.

Cheers,

Dave

Hmmm, no it doesn't! Anyway, as a practical radio user, I know that to transmit a true square wave, as in keying Morse code, you need a circuit that will respond without rounding off the corners or spreading out the signal,. This means creating a wider and wider bandwidth in order to accommodate all the higher harmonics, thus getting further and further away from the ideal. Too square and it will 'ring' or oscillate at the 'corners;' of the waveform, giving 'key clicks'. Too round and it will sound muffled and indistinct.

Also, re PW, they also do CDs of collected simple articles and projects, plus two books on Technical for the Terrified, etc.

Muzzer, you too, eh? Join the club! Rob Mannion was giving a talk at Otley Radio Club, and recognised me in the audience. I had to stand up and take a bow!