You Can Have My TIPs When You Pry Them From My Cold, Dead Hands 170
szczys writes: Should you trash brand new parts developed decades ago and adopt newer models? The argument centers around TIP parts which are a standard type of transistor developed in 1969. This debate started out with a post from Tom Jennings who is known as the creator of Fidonet but works a lot with electronic hardware. Adam Fabio — himself an Electronics Engineer — picked up on the argument for the other side. He attests that if used in the proper application these parts are second to none.
adam fabio (Score:1)
Are we supposed to know who adam fabio is? Why do you think its important to tell the readers who Tom Jennings is but not who adam who is?
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Adam Fabio — himself and Electronics Engineer
I'm more interested in the name of the Electronics Engineer.
If your hands are cold you could use other parts (Score:2)
If the part were critical, it'd be running hot enough that you had to worry about using the right one. If it's still cold even when you're pumping power through it, you've probably got lots of design headroom for evaluating other parts...
TIP series are good devices (Score:2, Informative)
...but the things expected have evolved from that time until now. The TIP devices, being bipolar technology, are inherently less efficient than their modern cousins, which are mostly CMOS FET technology. The operation of bipolar and FET transistors is fundamentally different, and what is taught today very often overlooks bipolar devices altogether. Further, the older devices tend to be physically larger than modern equivalents, which is a natural consequence of the lower efficiency demanding more surface
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And yet, carburetors are used for a lot of engines - small engines such as those in lawn mowers or chainsaws and also in light aircraft engines.
Sometimes the smaller device does not mean better - SMT parts, for example, are more difficult to solder pretty much require etching a PCB (instead of using a perfboard or point-to-pont construction). Also, if I am building an electronic load or an analog amplifier, the transistors are going to dissipate a lot of heat anyway, so I might as well get a TO-3 part.
Carburetors are evil! (Score:2)
Carburetors are evil! They tried to kill Harrison Ford (Han Solo) [go.com] and should be banned
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The TO-3 part was a response about size. And while I am able to etch a single sided board, I found it is too much hassle for me compared to using a perfboard since I am not making multiple copies of the same device.
And if I wanted to build a transistor amplifier (I recently completed a tube amp that does not use any semiconductors, and plan to build a couple more (but different)), I would most likely use linear design, not switching. Disregarding any comments about sound quality (which depends on more thing
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TO-3 and TO-204 power MOSFETs are rare and expensive these days so it is best to avoid them in new designs. Neither Mouser nor Digi-key have any available. I have a bag filled with NOS IRF351s.
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I guess it is easier to me to solder bigger components. If I make a mistake (or want to improve the device) and need to desolder a part, with SMD it is even harder to do properly (without destroying the part) than soldering it. Something like SOT is more difficult than TO92. and DIP is easier than SOIC and much easier than TQFP, especially desoldering. Also, with DIP I can use sockets (that are cheap). PLCC would be OK too, but not many modern components are PLCC.
And if I do something with tubes I do not ev
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I have a desoldering gun, it does not take a long time to desolder a big DIP chip. While most parts are cheap, I still get the inconvenience of having to buy one, so I'd rather use sockets.
I have a hot air gun, but so far, my rate of success with it (managing to desolder a chip without destroying a nearby chip) is not that great.
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being bipolar technology, are inherently less efficient than their modern cousins, which are mostly CMOS FET technology.
This is not insightful or informative, it's plain wrong. Firstly, the competitor to BJT is MOSFET, not CMOS, since the latter implies two transistors not one. Secondly BJT and MOSFETs have substantially different characteristics. BJTs are faster linear amps, MOSFETS are faster at power switching, whereas BJTs handle very high powers better MOSFETS have better drive characteristics etc etc.
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Bipolar transistors and FET works on very different principles. For example, the input capacitance of a FET is much higher which can bring some problems in "high frequency" (sometimes, not so high) designs.
FET are also more sensitive components (Vgb can get quite high due to static electricity and lead to component destruction) and may need special driver circuits (for example to make the switch faster).
And, don't forget that more and more of "today's" components are SMD only... which makes using them on a
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Gate capacitance on a junction FET (not all FET's are MOSFETs) and base to emitter capacitance on a typical bipolar are comparable. However, the best-case use for a bipolar is a cool little magnetic device called a transfluxer (no, I am not making that up; see US Patent number 4,459,653 for the 'bifluxer' variant and the citations to the original, Google's link is https://www.google.com/patents... [google.com] ). A transfluxer-based inverter is very close to being as efficient as a MOSFET design. (And, don't worry, t
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But of course I had to misremember intersil when I meant International Rectifier (HEXFET is a trademark of I-R, by the way).
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... what is taught today ...
Your electronic gear is no longer repairable. Just toss it out for the latest and greatest. Stay calm and carry on.
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They are less efficient in most although not all hard switching applications but most power MOSFETs now are not suitable for linear applications.
And if your application calls for high powe
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MOSFETS can be used for analog output, it's simply a question of designing the circuit properly. In particular, the high input impedance of power MOSFETS at audio frequencies makes them appropriate for being driven by an op-amp.
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JFETs will always be low power devices compared to MOSFETs or bipolars because they have limited enhancement range do to the clamping of the gate to source voltage by the inherent gate to source diode. They did make higher power JFETs in the past but even then they were pretty low power.
Do something productive ... (Score:4, Insightful)
If you're actually concerned about this, rewrite the tutorials rather than complaining about them. A big part of the reason why reach for those parts is because someone taught them how to use them.
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You should have gotten a +5 for that point.
old clunky junk (Score:3)
Not sure why the "hobbyist" community holds onto old crud like this when newer things are cheaper and better, win win. Darlingtons are terribly inefficient. It will work fine for turning on a lamp from your arduino but so will 10,000 different FETs.
Like people using ua741 opamps that are older than me. At least move into 1980 and use an LM358 or something. Same price or cheaper, and the input actually goes to one rail. Still very old junk, but significantly less so.
I guess people read some circuit from 1975 and figure they need to use the same parts verbatim, buy a bunch and are stuck with them making new circuits, that they then post, and more noobs buy the same old junk!
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The same reason why some people still build stuff using tubes even though a IC could do it, easier, faster, and cheaper.
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Except when it can't There's a great deal of continued tube use in harsh environments, where the temperature sensitivity of semiconductors presents a very real limitation, or where their very small size makes them more vulnerable to radiation damage, there's the behavioral differences when overdriven, and the list goes on.
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I work with Apple products and often use them in an production line with PDF document for publications.
Work, for real, with Excel, Photoshop, Illustrator and a slew of PDF tools every day. Both command line and GUI.
If you can tell me how Linux is better for that I will give you a medal.
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If you can tell me how Linux is better for that I will give you a medal.
Linux is better because it's webscale and can fight off systemD infections since it uses MongoDB to reprioritize client engagement in customer-facing paradigms.
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On the other hand, if you want to work with FPGA, you'll be toast with your mac as Xilinx and Altera both support Linux and Windows but no Mac...
Linux UI is not that poor... don't mix Linux and the apps... I'm quite sure that The Gimp on your Mac will give you the same time loss than The Gimp on Linux... it's not Linux' fault but the Gimp's fault.
For coding tasks, Linux is on par (or sometimes superior) to the other OS... Netbeans, Eclipse, Microchip's MPLABX and even Arduino are all supported on Linux..
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Sure, if you work with FPGAs linux is great, but then, I work with PDF's. What does FPGA's got to do with it? I am not going product a PDF pipeline in FPGA logic. Mind, you that WOULD be a hell of an interesting project and if it works.... $$$$$!
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GIMP's UI is not Photoshop.
No, it's shit.
When they make it so that you can do layer operations without reading a manual, then gimp will be a worthy replacement for photoshop. Every time I use gimp I have to go figure out how to use it again. Every time I use photoshop it's like putting on my favorite robe. If gimp's interface were not the typical total shitfest which OSS developers usually create, perhaps things would be different.
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Gimp's biggest problem is the lack of a full 16-bit-per-color capability for all operations. Layer operations, while still somewhat clunky, aren't bad for the simple work (not more than 4 layers) I've done.
I've bought Photoshop 3 times; never again. I don't process photos for a living, so it's not worth it.
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Bingo
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Alternate windows manager does not help me when I ACTUALLY WANT TO PRODUCE A PROFESSIONAL PDF FILE.
Linux cannot do that, but then, my customers are paying me for that. "Hey, you PDF file has the wrong fonts in, it looks like sh!t on some readers and no metas, but at leat my window manager is great".
How long do you think they are going to pay me?
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"Like people using ua741 opamps that are older than me. At least move into 1980 and use an LM358 or something. Same price or cheaper, and the input actually goes to one rail. Still very old junk, but significantly less so."
My favorite is the oldy-moldy OP-10. I happened to be interested in a _very_ low Input Impedance Op Amp at one time, (Not FET stuff...). Ten OP-10s in parallel brought the Input Impedance below 0.01 Ohms, and with some attention paid to topology, a linear sensitivity down to the 1:1 Pic
Re:old clunky junk (Score:5, Insightful)
Looks like we have a component snob here.
Some people are amazingly derogatory about the "maker community". I wouldn';t exactly class myself as one but I don't get the hate. As far as I can tell, the maker community is about making (duh) *things*. The point being, the final thing is what matters and the process of getting there is "whatever works". This is fine. The emphasis is not on building something using the best tools available, it's about getting to the end goal.
Makers as a result tend to only care about the guts of the circuits and stuff if those affect the final thing. Hence the near obsession with Arduino. It reduces 99% of the work to an already solved problem, even if the solution is in some sense not optimal.
But they're not trying to make the smallest/cheapest object, they're trying to make AN object generally that no one else has.
And you know what? There's nothing wrong with that.
Not sure why the "hobbyist" community holds onto old crud like this when newer things are cheaper and better, win win. Darlingtons are terribly inefficient. It will work fine for turning on a lamp from your arduino but so will 10,000 different FETs.
Who cares? The price probably isn't significant part of the overall cost. $MAKER has a box of darlington pairs, all $MAKER's friends have them and he can probably pick up a replacement in a Maplin on a Sunday if he blows out one away from his normal supply.
Hobbyists oddly enough don't tend to have a trade account with Farnell or want to wait until Tuesday morning (which to them translates to next Saturday) to get the part.
And if the maker in question has a circuit known to work and give enough power, there's no point saving a buck but adding a few hours to a multi-hundred hour project.
Like people using ua741 opamps that are older than me. At least move into 1980 and use an LM358 or something. Same price or cheaper, and the input actually goes to one rail. Still very old junk, but significantly less so.
I say this as someone who refularly uses the sub 3V micropower rail to rail single supply op-amps from TI and Linear (ever seen an 8 pin BGA before?). A 741 is essentially a tank with 8 pins. For low spec stuff the performance is perfectly fine. If you don't need low power, rail to rail operation or high speeds they work and do the job perfectly. They are also infeasibly robust.
For a circuit which only needs a 741, you may as well design it for one. There's lots of pin compatible ones you can swap in at a pinch if you really need. But again it doesn't matter.
741 does the job if the job is not to have the most optimised circuit but instead one that does the job.
I guess people read some circuit from 1975 and figure they need to use the same parts verbatim, buy a bunch and are stuck with them making new circuits, that they then post, and more noobs buy the same old junk!
No the problem is yorr goals and attitudes are different from other people's. You don't understand them so you assume they're idiots. I know a bunch of them and they're not.
If you tried to make some of the stuff they made they'd probably be shaking their heads in week 3 when you've been poring over datasheets and finally sent your circuitboard plans off to be made when they'd have their 4th arduino already bodged inside the laser cut wood case with duct tape and jumper wires with the thing mostly working.
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Yes, and to get from "mostly working" to "fully working" they'll have to pore over the same datasheets for 3 weeks too. I mean, Jesus, I had to make a stage prop that involved a switch, a resistor, 12 LEDs and a switch, and it still took a bunch of analysis of the LED datasheet to make something that was going to work reliably as a stage prop instead of burning out halfway through the second performance.
Why would a total noob even do that? They would just buy an LED driver shield, and do absolutely no circuit design. Make it all up in code.
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Yes, and to get from "mostly working" to "fully working" they'll have to pore over the same datasheets for 3 weeks too.
Nope, because they're not trying to get the most optimised working thing.
I've seen some of the stuff they cobble together and frankly it leaves me shaking my head sometimes, but darn it if they don't get stuff cobbled together awfully effectively and remarkably fast.
Yeah it wouldn't be a great way of making a product (but that's not the goal). And sure, if they're trying to make something s
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oops realised I replied to your quote of an AC, assuming it was you. Sorry!
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Arduino fill a niche that nothing else can fill...
My last design used some PIC16F and other... it took me several hours to get the program running on the prototype (breadboard and such)...
But last year's Halloween, I had a "last minute idea"... an Arduino, one servo, one movement detector module, some bamboo sticks, some nylon wire and a plastic spider... It took me about 1/4h to wrap it up (and 10 more minutes to install it in my entrance "black chapel")... that's the Arduino real strength... You can hack
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holds onto old crud like this when newer things are cheaper and better
Monkey see, monkey do.
The vast majority of hobbiest, and definitely in the subset of the Arduino crowd are not practising electronics engineers, they are people of all backgrounds dabbling into electronics and achieving great things. Ultimately though they achieve their goals without ever understanding how or why. By reading an online tutorial, sometimes even basic enough not to include a schematic but an actual drawing of a part and coloured lines showing the hookup they are building things that work, they
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Many of these hobbyists don't have the understanding needed to select suitable replacement parts. Even just picking a newer op-amp is hard for them, because they don't really understand op-amps or how to read datasheets or what parameters they need to look at. Forget about changing a few passives to account for different parts.
Thus they tend to rely on old circuits and information, and thus want to use those old parts. If you look on Make half the electronics tutorials are clearly written by people who don'
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Cheaper?
It's hard to be cheaper than something that is already in your junkbox. Don't have a junkbox? Show up at a hamfest and some time around noon somebody will give you a ready filled junk-box for free. Most likely it is the junkbox of a recent silent key (ham who died).
Don't worry. Some day those old parts will be rare and expensive so they will only get used for fixing old stuff and maybe making audio amplifiers for people who are nostalgic for the sounds of their childhood. Hobbyists will then be bui
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The 358 is not always a good replacement for the 741 although in most circuits it would not matter. It's input bias current is the opposite, it has no input offset voltage adjustment, and single operational amplifiers are more useful in circuits where the power supply is bootstrapped.
There
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Programming microcontrollers is difficult, especially debugging the program (it's not like with a PC program where you can use a debugger or log everything etc), Arduino makes it a bit easier. Discrete logic is easier still, but if you want to do anything complicated the 74xx chips take up a lot of space.
Also, there is such thing as "good enough". If I want to drive a nixie tube (or something else that requires relatively high voltage and low current), I'll use a MPSA42. Why? Because it's cheap and works OK
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It is still more difficult and also the chip needs to be programmed in the first place. The programmer also may not be cheap. So, if all I need is to flash a LED, I'll use two transistors or a 555 chip. For something complicated, yes, a MCU is better than a board full of 74xx or 4xxx logic. And for stuff that needs Ethernet connection, I'll just use Raspberry Pi.
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You can find cheap PICKit 2 on EBay. You can also find cheap AVR programmers, JTAG interfaces and you may even find cheap (E)EPROM/PAL/GAL/PIC/AVR/8X51 programmers like the TL866 which is supported both under Windows and (using a 3rd party project) under Linux.
You can buy PICKit 2 + TL866 + AVR programmer + JTAG for less than 200$ and it'll open you a very vast choice of devices... more than needed for an hobbyist.
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200$ is a lot of money. Most of the time the device I want to build costs less (in parts). Even if I used an Arduino. Then again, I don't do a lot of stuff with microcontrollers. It's tubes, discrete logic, analog stuff or a Raspberry Pi (when I need Ethernet support).
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Less than $200 for the 4 programmers... and you've got redundancy (TL866 allows to program both PIC and AVR, the mentionned PICKit 2 is for ICSP debugging (and direct interaction from MPLABX) and the AVR programmer would allow you to program "in situ" (TL866CS is only through the ZIP connector).
TL866CS => 38$-50$ (depends on the extra adapter that you want to get)
Byteblaster compatible JTAG => 12$
PICKit 2 => 12.5$
STK500 (AVR) => 20$ (there are cheaper alternatives)
If you buy through EBay and Chi
Re: old clunky junk (Score:2)
You can also buy an Ardiuno knockoff on eBay for under $10. Pick one that uses a socketed through-hole AVR processor, and you can use it like a development system. Prototype and debug your design. When it's finished pull the chip out of the Arduino to build onto your custom board and plug in a fresh chip.
Also you can get Arduino clone boards from places like banggood.com for $3.20.
link here [banggood.com]
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Ok, I will bite. I am an Arduino enthusiast. While I know there are lots of microcontrollers out there, are there any platforms out there that allows a hobbyist to quicjly build a few circuits because the infrastructure around the controller chip is very easy and foolproof to us. I am talking about a SYSTEM here, not the Microcontroller chip itself. Arduino does a lot of interfacing for you. I know about the GPIOs on the Raspberry Pi, I build a circuit with it only 4 days ago. The Arduino was much easier to
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We all know Arduino makes things easy. The problem is there is a huge segment of the maker community who get all excited about the blinkenlights but have no drive to venture outside their comfort zone, and another huge segment which makes no attempt at providing the tools, know-how, or encouragement for them to do that, and instead just keeps building on the hype-du-jour even when it doesn't make sense. This is how you end up with a large chunk of the community being 10 years behind the curve, or who will k
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1) Arduino with FPGA shield
While it may sound stupid (as you said, the shield was more powerful than the arduino), don't forget that FPGA programming is much more complex than Arduino/C...
FPGA could be great to generate a video signal but will be very poor when you want to do string processing and maths... FPGA and Microcontroller don't share the same kind of uses...
So, the FPGA shield is not as stupid as it could feel..
2) Arduino is a commodity
Even if you can program a microcontroller in assembler, using d
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The dumb part is that you can stick an AVR-compatible core in the FPGA itself and skip the Arduino. Basically, an FPGA shield for an Arduino makes no sense when you could have a standalone FPGA board that is also Arduino-compatible by virtue of embedding an Arduino clone inside the FPGA itself. That would be a much better way of jumping on the bandwagon without doing something that is, design-wise, completely silly. It would run faster than a real AVR to
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The dumb part is that you can stick an AVR-compatible core in the FPGA itself and skip the Arduino.
Well, you also find Arduino FPGA shields like the "Gameduino" where the FPGA comes preprogrammed... Even if the user may reprogram it, if don't know anything about FPGA, ha can still use it...
Don't forget that Arduino is also a whole community sharing tips and code... the differences between AVR and Arduino are shields, easy to use libraries and community...
And, well, I don't see the point in using an AVR core in an FPGA... you could use smaller CPU cores which would leave you with more gates...
But... why? Why use a module when you can just stick the AVR right on your board and get a lot more flexibility? It makes a lot more sense to buy the USB-TTL converter as a module, since at least that is pretty much universal. Or just use a serial connector and have the USB-TTL converter as an external cable for testing/programming if your device doesn't rely on USB being around to actually function.
If you use
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From a hobbyist perspective, building that board is very hard. The Arduino does all the legwork for you and you only have to plug your external components into the board, which already exists. That is the main point. Arduino gives you the infrastructure to use the MCU and only worry about the externals.
When one comes from the point where learning about things like pull-up resistors is exciting (like me) building an actual board is something you leave to gurus and experts.
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The thing is, it really isn't. Assuming you're wiring things up on a breadboard, what you do is:
Sure, it's a couple more steps than "Connect Arduino to US
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I was talking about the ACTUAL SURFACE MOUNT BOARD. As OPPOSED to using a breadboard. And that IS beyond hobbyist use.
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An example? One that is easy to use and would do well as a platform to learn basic FPGA programming?
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We all know Arduino makes things easy. The problem is there is a huge segment of the maker community who get all excited about the blinkenlights but have no drive to venture outside their comfort zone
It's a problem for you if people aren't comfortable?
Just be happy these people are trying to create things.
Ask yourself this question: if you want to actually build 5 or more of a particular project, would you just get an Arduino for each?
This question is shit. How many more? 50? 500? It doesn't make sense to actually design your own circuit until the number gets up there someplace. Certainly at 5 I would just buy the Arduinos.
Or would you give a shot at researching the available microcontrollers, perhaps sticking to the AVR series, perhaps not, picking the right one, then making a custom board design, trying to optimize it a bit, and probably end up coming up with a much more robust, compact, and efficient design as a result, and learning a lot in the process?
Yeah, all that costs a lot more than just buying some $3 Arduino Nanos from China. People are part of the problem because they solve their problems efficiently? Maybe you are part of the problem, spending your tim
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I would do my own design at 2. Sometimes at 1.
What you and the people with this problem don't realize is that it's downright trivial to stick the same micro that's on the arduino on a broadboard, give it 5V and ground, and it'll run. You're presumably already designing the rest of the circuit that plugs into the Arduin
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No it doesn't. All it takes is to take the pins on your design that say "Arduino goes here" and instead plug in a bare AVR chip.
No, you're missing the point. Designing the PCB takes time that you could spend watching TV or shooting marbles. If you're only making a handful of units, why not just plug stuff together and ship it?
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So what are you plugging into the Arduino?
I'm not talking about the person who is still at the plug-shields-together stage and doesn't really know how to put more than 4 parts on a breadboard. Nor am I talking about some kind of custom solutions consultant who really doesn't care about efficiency and just wants to deliver the product ASAP with a minimum of effort and doesn't need it to be cost-optimized.
I'm talking about curious makers who start building things on top of the Arduino platform, understand bas
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I'm talking about curious makers who start building things on top of the Arduino platform, understand basic digital electronics... but then somehow never move on from basing everything around the Arduino board, and think there is some kind of magical pixie dust in there and that running a bare chip is rocket science.
I think it's more that if you never move into production, and you never need more CPU, that the Arduino is basically impossible to beat. Maybe this new C.H.I.P.S. $7 or $9 or whatever thing will be the new contender, but the Arduino platform was the first to offer what it offers, and is still the cheapest to offer what it offers. It's just very easy to get things going, in spite of the outdated libraries and documentation lurking out there.
For a user who is only making a handful of devices, the only reason
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I agree that if you're just plugging shields together and if you don't care about size or cost and if you're not building any custom electronics then the Arduino makes sense, even in production.
But really, I'm not focusing on commercial production here, I'm talking about hobbyists. Not those plugging in shields, but those designing their own. And making their own widgets using the Arduino as a base for their own custom electronics design. Often, people who are already designing their own boards, or at least
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Except that PCB design takes time, using a raw SMD AVR like the one you find on the mini pro/nano is not an easy task (unless you have some reflow oven) and the module already takes care of some of the burden...
That said, my latest design was PIC-based (using outdated 16F877 because I had it on stock and it's for a 1-unit production) and not arduino-based...
But should I use a design using some Arduino, I think I'll use the already made module instead of a DIP socket and a ATMega328 with some external compon
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10 years behind the curve
Well, maybe not quite exactly, but Arduino started in 2005. That's ten years ago. Then again, we still have people programming C with /* */ comments, and variable declarations at the top of the function, as though C99 never happened over fifteen years ago. (For instance, STM32 library/sample code is still written that way, but just try to find me an ARM C compiler that doesn't support // comments!)
What bugs me most about Arudino is that it's an 8-bit processor, from the dawn of the Flash-in-CPU era, still
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I completely agree about the chip choice issue. At least it's not PIC16/18, which were horrible for C (especially PIC16), but the maker world really needs to move on to ARM and Cortex-M0. However, even worse than the ancient chip choice are the people blatantly abusing it to do things it's just a horrible choice for.
The thing is at that point you might as well use the bare chip
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I'd add that /* ... */ comments are cleaner and more powerfull than their // counterpart :
It allows things like : /* the bar parameter*/ , char *barbar /* the output buffer */) {...}
void foo(int bar
End of comment is explicit (unlike the // where the end is implicit) which makes more sense with C that uses explicit end markers anywhere ";", "}"; "]", ")"... and "*/"...
As for the variables declaration in the beginning of the function, it's also cleaner... Having a cleaner code requires more work but, in the e
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I'm not talking about in-line comments, I'm talking about blocks of comment-only lines and right-side comments. Sheesh.
And variables being declared in the scope where they are used is cleaner because it's better in terms of locality. Especially when you make functions way too long. Declaring "int temp1" at the top when it's used in a single if statement near the end of a long function is hardly "cleaner".
And I can't see why you're bringing function and parameter declarations into this.
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I don't see anything wrong with a USB HID interface for NES controllers. That's pretty much what AVR-style micros are just right for. Assuming you're using an AVR board with a native USB uC of course, like a Teensy++ or similar. I've done similar things myself, both using custom PIC designs and off the shelf AVR breakout boards. Also, LUFA, which I assume you're using, is great and in general much higher quality code than a lot of Arduino stuff.
If you're using software/bit-banged USB, you really should look
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Video logic in FPGA reminds me of the "Gameduino" shield... (http://excamera.com/sphinx/gameduino/) except that to use it, you don't need to know anything about FPGA and it can be used by people who don't even know what an FPGA is.
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Yes, I was thinking of the Gameduino shield - it's completely silly. It even has a coprocessor inside the FPGA that is user-programmable and runs much faster than the Arduino. The SPI interface is a stupid bottleneck. It would make a lot more sense if they hadn't jumped on the Arduino shield bandwagon and instead had implemented it as a stand-alone product with its own CPU core (which could just as well use the Arduino libs if they'd wanted; it wouldn't require FPGA knowledge either).
Think about it - the Ga
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I use a Pi as an AVR programmer. The Pi has SPI on its GPIO interface (or you can bitbang, avrdude supports both)
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Where are the advantages? (Score:5, Insightful)
I have no doubt that old-school TIP series transistors still have plenty of uses today, but the article is completely devoid of any examples. All it is saying is "look, these things aren't unusably bad for driving motors - they're just bad." Tom's post is still dead-on - using old school NPN BJTs for switching heavy loads today is completely dumb, and just because he exaggerated a bit about just how bad it can get doesn't mean he's wrong.
I was hoping for some insight, like a discussion of robustness (I've blown FETs way more easily than I've blown BJTs), or perhaps use in analog applications, or anything else really. But nope. TFA is literally just confirming the findings that it's trying to disprove, while providing absolutely no counter-examples. Somehow feels like par for the course for Hackaday these days...
I use old school jellybean parts all the time, sometimes because it really doesn't matter (driving a relay? meh, throw a BC547 on it, who cares, it's relatively low power anyway), sometimes because it's all I have lying around, but sometimes using ancient devices is actually very dumb, and I wouldn't turn a motor on and off with a BJT these days.
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There are also some pitfalls of MOSFETs he should really mention (probably why people are using these old BJT power transistors is they are a bit more forgiving in this respect). When driving motors and relays, you often get some inductive 'kick', and this will capacitatively couple across the MOSFET's gate and go right back to the microcontroller's pin. Usually this results in just the microcontroller crashing, but it may also result in latch-up which can quickly destroy the microcontroller (I've seen it h
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To be fair, I always had to put diodes across motors and relays when using BJTs. I'm not sure if it coupled back through the transistor or the rails, but I certainly got micro resets and crashes if I didn't. It's always a good idea regardless of what switching technology you use.
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I have not encountered this problem myself although I might not have noticed and I tend to be paranoid about interface circuits anyway. My guess is that the excessive reverse transfer capacitance of the MOSFET allows the high dV/dT from the inductive kickback to get into the microcontroller. This would be exasperated by a drive circuit intended for the "high impedance" input of the MOSFET compared to a bipolar transistor where the low impedance drive circuit would just absorb it.
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For many loads however using a bipolar transistor is more economical than a MOSFET simply because of economics. Current density of a bipolar transistor is higher allowing less die area making them less expensive. Insulated gate bipolar transistors have the same advantage over MOSFETs.
This becomes more important at higher voltages where MOSFET die size scales by the square of the voltage but it still applies at low voltages.
We actually use them in our telescopes (Score:5, Informative)
Needless limiting of options (Score:5, Insightful)
Where to begin?
Should one even bother to do anything about advice from someone who goes on about enhancement MOSFETs while everything else is rubbish, and then present the circuit symbols for Junction FETs as examples? Makes one wonder what else is inaccurate there.
The actual advice of throwing out anything designed in the past century is at sensitiveresearch.com/DoNotTIP/index.html [sensitiveresearch.com].
Where not only the so-called TIPs, (by which is meant a certain series of reasonably popular power transistors in TO220 packages, designed by Texas Instruments) but also other devices such as 2N2222, LM386, and "bipolar transistors" and so on, are no longer to be used. Just because they might not be the best choice for switching loads controlled by an Arduino or similar.
This makes for a needless limiting of options -- If all one ever does is to turn things on or off from some microcontroller maybe, but with whatever designs I make I find that to be a small fraction of what is happening. The rest are things like multi-frequency linear or RF where all kinds of semiconductor devices might be applicable. Even vacuum tubes in some cases.
And then looking around the site and discovering the author is in his own words, "reasonably obsessed with the early history of electronic (not necessarily digital) computing" --- and then he advocates discarding what amounts to the elements of the analog electronic computers? This does not ring true.
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One thing is true about the old parts, though... you can still buy them. I've had occasion to work on some 15 year old electronics, and none of the bigger chips are made any longer. We can still get 741s to fix our 40 year old spectrometer, but no
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The 7400s stayed in use for a long time in education, as they were a lot more durable than their CMOS counterparts in the 4000s. TTL doesn't die if you handle it without antistatic precautions.
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Actually, they were. Because digital computers either were too big, too unreliable, or too hard to use.
Discrete logic was brought into play by Apollo (you can thank the Apollo Guidance Computer for basically bringing the 74xx series logic chips to
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What's most inaccurate is that he says that using a MOSFET means always a really simple circuit with the microcontroller directly connected to the gate of the MOSFET and nothing else in the circuit (except the pulldown resistor). In Microcontroller And MOSFETs 101 you soon learn about inductive loads and the problems they can cause, relays are the popular example - when you turn off the current to the relay you get a big voltage spike over the MOSFET. This capacitatively couples over the gate and zaps the o
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Where not only the so-called TIPs, (by which is meant a certain series of reasonably popular power transistors in TO220 packages, designed by Texas Instruments) but also other devices such as 2N2222, LM386, and "bipolar transistors" and so on, are no longer to be used. Just because they might not be the best choice for switching loads controlled by an Arduino or similar.
So, I am not an EE, but it seems like what he's actually saying is that the MOSFET takes an order of magnitude less turn-on current and that it wasts an order of magnitude less power as heat. Is that true? And if so, why would you not want to save power? Are your driver transistors doubling as a heater?
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Where not only the so-called TIPs, (by which is meant a certain series of reasonably popular power transistors in TO220 packages, designed by Texas Instruments) but also other devices such as 2N2222, LM386, and "bipolar transistors" and so on, are no longer to be used. Just because they might not be the best choice for switching loads controlled by an Arduino or similar.
So, I am not an EE, but it seems like what he's actually saying is that the MOSFET takes an order of magnitude less turn-on current and that it wasts an order of magnitude less power as heat. Is that true? And if so, why would you not want to save power? Are your driver transistors doubling as a heater?
A lot of the energy budget depends on the circumstances. When running on batteries, power draw is much more of a concern than when running on mains power. Similar with heating -- it may or may not be anything that needs to be attended to. Now having said that, there are several good reasons to use the MOSFET instead of the bipolar transistor, but they are not so overwhelmingly good that it makes sense to discard all kinds of bipolar transistors just because ot that.
The turn-on current for the MOSFET comes
TIP? (Score:3)
The parts were widely used because they were very cheap, and widely available. The early ones used a plastic that tended to burst into flames if the device was overloaded.
There are generally perfectly adequate alternatives with the European Standard numbers (BCxxx). It is unclear why these people are promoting a strangely obsolete technology, and the OP is not much help in understanding any of the relevant issues.
fidonet... (Score:2)
Re: The 555 timer sucks. (Score:2)
arent we at the point where SOC's are cheaper than 555's?
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Maybe not a microcontroller, but a whole circuit.
Before high power LED bike lights were commercialized, I made a daylight visible rear light for my bike after I got rear ended, using 6 x 1 watt red Luxeon LEDs. I wanted it to flash a pattern so it would show up in a driver's vision, but for night time use I wanted it to be less bright and be a steady light. While the 555 timer is very very cheap and a PWM circuit for dimming the LEDs and flashing them could easily be made, an ATtiny13 turned out to be a che
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Sure, people will scream "why waste a microcontroller on something a simple 555 timer can do." The answer is "because the microcontroller costs less and is way the fuck more reliable."
On the other hand, a microcontroller needs software, which means a development and programming toolchain. Those tend to change fairly often -- come back to that project in a few years and you might have a whole new IDE to learn.
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"TIPs" refers to Texas Instrument Power devices. A _Trade_ Name. A more Generic name is BJT- Bipolar Junction Transistor, of which TIPs are a variant.
The Summary is one of the most ignorant in recent Slashdot memory. It's not even worth being labeled "Flamebait"; not enough thought was given for that designation. BJTs thrive in all sorts of Analog Markets to this day.
But, well, Samzenpus...
"Adam Fabio — himself and Electronics Engineer..." What the Hell is that supposed to mean?
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Just like the 2N3055.. Yes, old. but in some cases, absolutely perfect for the job. Usually as linear pass transistors for power supplies :D
There is plenty of reason to avoid the 2N3055, well actually to avoid the TO-3 [wikipedia.org] packaging. The package flexes when mounted, which can cause poor thermal transfer to its heat sink. TO-3 are manufactured to be curved so as to help ensure good thermal contact, but the curvature isn't preserved if the TO-3 is removed.
References: OnSemi's Application Note 1040 [onsemi.com], and Burr-Brown (TI) Mounting Considerations for TO-3 packages [ti.com].