[QUOTE=aydin690;36700180]A lot of people have been asking basic questions. Here's a great all around book for people who want to learn the basic practical stuff:
[URL]http://books.google.ca/books/about/Practical_Electronics_For_Inventors.html?id=NmD0SD1-1YwC&redir_esc=y[/URL]
Imo it's better than art of electronics that you guys are suggesting for newbies because it's more practical, up to date and it doesn't go into too much theory.[/QUOTE]
The Art of Electronics [b]is[/b] a practical book compared with many other electronics books I've read, it teaches how to design good reliable circuits using very little complex math, many other books tend to omit quite a lot of very useful information, obscure it with a lot of math or give a poor explanation.
Theory is extremely important, if you don't learn it fully your circuits will be of poor quality (assuming they work) and you will have trouble understanding the details of how they function, and more importantly their limitations.
When I started getting into electronics I spent more than a year just learning the theory before I built a single circuit, as a result even my early designs were of decent quality, the Art of Electronics was and still is my main book of choice and one I highly recommend anyone serious about electronics read.
[QUOTE=Chryseus;36703478]The Art of Electronics [b]is[/b] a practical book compared with many other electronics books I've read, it teaches how to design good reliable circuits using very little complex math, many other books tend to omit quite a lot of very useful information, obscure it with a lot of math or give a poor explanation.
Theory is extremely important, if you don't learn it fully your circuits will be of poor quality (assuming they work) and you will have trouble understanding the details of how they function, and more importantly their limitations.
When I started getting into electronics I spent more than a year just learning the theory before I built a single circuit, as a result even my early designs were of decent quality, the Art of Electronics was and still is my main book of choice and one I highly recommend anyone serious about electronics read.[/QUOTE]
Not saying art of electronics is bad book, quite the opposite actually. I'm just saying, there are other books that we can recommend people that don't know anything about electronics.
Running out of stuff to take apart so I thought why not take apart my Samsung ML-1865 laser printer.
[img_thumb]http://i.imgur.com/Muctd.jpg[/img_thumb]
[img_thumb]http://i.imgur.com/7y5bl.jpg[/img_thumb]
[img_thumb]http://i.imgur.com/e3OGI.jpg[/img_thumb]
[url]http://imgur.com/a/ewL1F[/url]
No idea how the Chinese manage to get this kind of awesome build quality for only €50.
[QUOTE=ddrl46;36720925]
No idea how the Chinese manage to get this kind of awesome build quality for only €50.[/QUOTE]
I've wondered this. There are so many printer models out there, each with different specific circuit boards (though probably with the same components, mind you). Mass production is how they do it, but I don't understand how they sell enough of each model when there are so many different models
Toner cartridges, they cost more than the printer itself which is kinda stupid.
You can buy cheap refills but they will only work so long before the drum wears out.
That said when it does eventually wear out you can buy yourself a new cheap printer and loot the old one for parts.
Get a refurb HP 4350 if you need cheap. Works out to 0.2p per page in toner and they are unbelievably easy to work on and repair. :)
Replaced the Fuser gear in one at where I work, 2 hour job.
[QUOTE=Tezzanator92;36727626]Get a refurb HP 4350 if you need cheap. Works out to 0.2p per page in toner and they are unbelievably easy to work on and repair. :)
Replaced the Fuser gear in one at where I work, 2 hour job.[/QUOTE]
Or you get a LaserJet 4 for about a dollar and never run out of toner.
[QUOTE=Staneh;36680651]Well, he will be using them mostly, not really building them.[/QUOTE]
I think the proper place to start with radio's would be a shortwave communications receiver. I cannot advise this enough if one wants to start with RF. Shortwave bands hold a lot more interesting stuff then the usual AM/FM bands do.
Only thing is, has been said before, it is expensive.
My first receiver was a Kenwood R-1000, and I must say, it is a very good radio for the beginner, plus, experimenting with antenna's as much as you like with it.
[QUOTE=ddrl46;36720925]
No idea how the Chinese manage to get this kind of awesome build quality for only €50.[/QUOTE]
Printer manufacturers actually sell them at a loss and then make money by selling overpriced ink cartridges.
[QUOTE=aydin690;36745466]Printer manufacturers actually sell them at a loss and then make money by selling overpriced ink cartridges.[/QUOTE]
Same with the xbox and wii, they only make money via games and extra hardware.
[QUOTE=DrLuke;36746611]Same with the xbox and wii, they only make money via games and extra hardware.[/QUOTE]
If I recall, the Wii still made money on hardware, though not much.
[video=youtube;lE62NOj-S2g]http://www.youtube.com/watch?v=lE62NOj-S2g[/video]
Little project I did just recently :smile:
[QUOTE=Staneh;36678059]So my friend wants to start with shit like antenna's and recievers to listen to frequencies and shit, but he has no idea how to start, he prefers something abot cheap to start with.[/QUOTE]
I know I'm late but RTLSDR is a fairly cheap way to get started. A lot of the DVB-T tuners for PC are in fact SDRs. They do from about 50MHz up to 2200MHz at 2.8Mbps. You want to try and get one with the Elonics E4000 tuner (becoming more rare now, they have been liquidated and demand has shot up) as they have the largest range. I am yet to receive mine from them, but "Cosy Cave" on eBay UK claim that they sell E4000 based tuners, and the reviews don't seem to say otherwise. He will then just need an antenna, for starting off just a wideband TV antenna can pick up a fair amount, otherwise you can use plain wire or go and construct a discone antenna if you want to get more advanced. If you want to receive below 50MHz you'll need an "upconverter" to increase the frequency. On Windows the main software used is SDR# and HDSDR, on Linux there is GNU Radio and gqrx.
Been working on learning Buck converters for about a week and half now, and my attempts at building a decent Buck converter have lead me nowhere. I'd like some advice please, the video is pretty self explanatory.
[video=youtube;XFZPNVMJ3Ic]http://www.youtube.com/watch?v=XFZPNVMJ3Ic[/video]
Here's a schematic of my attempt:
[img_thumb]https://sites.google.com/site/lonewolfscircuits/sitefiles/Buck%20Converter%20Attempt.png[/img_thumb]
I suggest trying a lower switching frequency, something like 20kHz is a good starting point.
Also at 370kHz D1 should be a fast recovery schottky diode.
Adding some feedback using a comparator would also be a good idea.
I had already designed a feedback circuit with a Zener as reference. I'd just adjust the voltage ladder in the 555 to change the duty cycle, hence the output voltage. Course this is just a really rough simulation, I haven't done all the math yet.
[img_thumb]https://sites.google.com/site/lonewolfscircuits/sitefiles/Feedback_Circuit.png[/img_thumb]
I'll try swapping out the diodes and lower the frequency too. So does longer ON time allow the inductor to energize more, hence storing more energy?
EDIT:
The 10Hz signal is demonstrating the output voltage changes, as an input to the comparators.
Do you guys think i can put a few supercaps in parallel and use them as a backup power system?
[editline]14th July 2012[/editline]
to power a TI msp430 5 series dev board, a cpld, and a few electromagnets and solenoids (the assholes here). I know i can run the ti board with a supercap for weeks and but i don't know how long the electromagnets and solenoids are going last.
[editline]14th July 2012[/editline]
[QUOTE=LoneWolf_Recon;36771883]Been working on learning Buck converters for about a week and half now, and my attempts at building a decent Buck converter have lead me nowhere. I'd like some advice please, the video is pretty self explanatory.
Here's a schematic of my attempt:
[img_thumb]https://sites.google.com/site/lonewolfscircuits/sitefiles/Buck Converter Attempt.png[/img_thumb][/QUOTE]
I don't have time to check your set up but i would also suggest lowering the freq, make sure your diodes trr is low enough (something like a 1N5817), and also make sure you're using a Electrolytic Decoupling Capacitor, something like [URL="http://www.digikey.ca/scripts/dksearch/dksus.dll?vendor=0&keywords=P975-ND"]this[/URL], and for inductor i'd use a radial lead RF choke ([URL="http://www.digikey.ca/product-search/en?FV=fff40003,fff80013,ffec0190"]these guys[/URL]).
Also, get your hands on this book:
Power Electronics: Converters, Applications and Design, 3rd edition
Ned Mohan, Tore M. Undeland, and William P. Robbins
Published by Wiley, October 2002
ISBN-10: 0471226939
ISBN-13: 978-0471226932
Not sure if it's late or not, but for those interested, apparantley there's some free online courses in AI programming, including lessons from the guy who won the DARPA grand challenge a few years back.
[url]http://www.khanacademy.org[/url]
[url]http://ocw.mit.edu/index.html[/url]
[url]http://see.stanford.edu[/url]
[url]http://www.udacity.com[/url] <- From the guy who lead the Grand Challenge winning team
[QUOTE=ben1066;36770528]I know I'm late but RTLSDR is a fairly cheap way to get started. A lot of the DVB-T tuners for PC are in fact SDRs. They do from about 50MHz up to 2200MHz at 2.8Mbps. You want to try and get one with the Elonics E4000 tuner (becoming more rare now, they have been liquidated and demand has shot up) as they have the largest range. I am yet to receive mine from them, but "Cosy Cave" on eBay UK claim that they sell E4000 based tuners, and the reviews don't seem to say otherwise. He will then just need an antenna, for starting off just a wideband TV antenna can pick up a fair amount, otherwise you can use plain wire or go and construct a discone antenna if you want to get more advanced. If you want to receive below 50MHz you'll need an "upconverter" to increase the frequency. On Windows the main software used is SDR# and HDSDR, on Linux there is GNU Radio and gqrx.[/QUOTE]
I've just ordered a dvb-t stick :3
[QUOTE=DrLuke;36779390]I've just ordered a dvb-t stick :3[/QUOTE]
You made sure it's one that's supported right?
[QUOTE=ben1066;36780512]You made sure it's one that's supported right?[/QUOTE]
Yes, one of the devs on freenode says he ordered the same one, and it's been confirmed to work.
[QUOTE=DrLuke;36780735]Yes, one of the devs on freenode says he ordered the same one, and it's been confirmed to work.[/QUOTE]
Ah yes, I see you there now :) Shall be fun to see what's going on around here.
Are you guys saying that I could buy a DVB-T tuner and use it as an amateur radio, given that I have the proper antennas?
[QUOTE=VistaPOWA;36787135]Are you guys saying that I could buy a DVB-T tuner and use it as an amateur radio, given that I have the proper antennas?[/QUOTE]
Yes. They even come with an antenna, which is crap though, but should be enough for a beginner.
This is one that has been confirmed to work: [url]http://www.ebay.de/itm/White-USB-DVB-T-RTL2832U-E4000-for-Windowns-XP-Vista-Seven-PC-SDR-GPS-P335-/170828244677?pt=US_Video_Capture_TV_Tuner_Cards&hash=item27c62826c5[/url]
Mind that you can only receive with those (unless I missed something)
If your in the UK [url]http://www.ebay.co.uk/itm/110898287043?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_2671wt_1186[/url] seems to be your cheapest option. I'm currently waiting for mine to ship, but people have been getting E4K tuners from cosycave. Yes you can only receive.
So I need 24 channels of very high resolution, NON PWM, dimming LEDs to control a bunch of NSL-32SR2 resistive optocouplers. I'm thinking of using 3 Ti DAC7578s (12Bit, I2C Bus, TSSOP16) but I need a [u]neat[/u] solution to up the current capacity because I'm not sure the DACs can handle 8 LEDs at 20mA itself.
Can anyone think of a part off hand rather than just using a ton of transistors? 3, 8 Channel Darlington Array ICs? :v:
Linearity is of the utmost importance.
you could use a DAC and an opamp to drive a transistor in it's linear region and thus manipulate the voltage, basically a linear voltage regulator.
[QUOTE=DrLuke;36799776]you could use a DAC and an opamp to drive a transistor in it's linear region and thus manipulate the voltage, basically a linear voltage regulator.[/QUOTE]
Or ditch the opamp and use a transistor with sufficient current gain (darlingtons for example) to drive the LEDs.
Just bought a Philips B3G97U 1957 tube radio for my first restoration project.
[img]http://www.thevalvepage.com/radios/philips/b3g97u/front.jpg[/img]
:rock:
I'm trying to regulate the speed of two 7-12 volt DC engines.
I was told in this thread [url]http://facepunch.com/showthread.php?t=1198296[/url] that i could use PWM to do this.
My question is, As I already asked there, Can i use an Arduino to do this or will i need to set up a circuit for this? Will it make the engine very jumpy and cause a lot of vibrations as opposed to letting it run regularly?
I know I'm asking a lot, But could you give me any hints on a good way of doing this? I'm basically wanting to create a way of steering without using a servo or any gears (Because I have neither available). Thanks in advance.
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