Books/links to learning how to read schematics
Apr 23, 2009 at 1:40 AM Post #2 of 9

Uncle Erik

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If you're just starting out, read "There Are No Electrons," by Kenn Amdahl. Then move on to the Navy manuals, and the books by Morgan Jones and Bruce Rozenblit. Also, make use of the free library generously hosted at Pete Millett's DIY Audio pages.

Sorry I'm not posting the other links - I'm on the iPhone at a Waffle House in Tucson. But Google those and nose around what you find. Reading symbols is the easy part - understanding why they're there takes a little more study. Don't worry, anyone who reads up will get it.

You might want to try building an amp like the CMoy while reading up on schematics. If you follow your learning with hands-on experience, it will sink in a lot faster. Good luck!
 
Apr 23, 2009 at 2:17 AM Post #3 of 9

BlizzofOZ

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Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif
If you're just starting out, read "There Are No Electrons," by Kenn Amdahl. Then move on to the Navy manuals, and the books by Morgan Jones and Bruce Rozenblit. Also, make use of the free library generously hosted at Pete Millett's DIY Audio pages.

Sorry I'm not posting the other links - I'm on the iPhone at a Waffle House in Tucson. But Google those and nose around what you find. Reading symbols is the easy part - understanding why they're there takes a little more study. Don't worry, anyone who reads up will get it.

You might want to try building an amp like the CMoy while reading up on schematics. If you follow your learning with hands-on experience, it will sink in a lot faster. Good luck!



Thanks... I've already built a Cmoy. Looking to move forward and I wanted to include understanding schematics. I understand there is more to it than that, but need to start somewhere.

Mmmm... waffles...

Anybody with other suggestion?
 
Apr 24, 2009 at 1:40 PM Post #5 of 9

BlizzofOZ

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Quote:

Originally Posted by danobeavis /img/forum/go_quote.gif
FWIW, I wrote an article called From Schematic To Reality that attempts to explain how to read schematics and how they map to the real world. It is written for guitar audio folks, but the same principles apply. Give it a look: Beavis Audio Research


Really nice write up... Someone posted your site to another question I had on building some speaker ams. I didn't notice this page.
 
Apr 24, 2009 at 6:05 PM Post #6 of 9

NelsonVandal

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Start playing around with LTSpice. Look at what others have done, and start with some simple schematics and move on to more complex. There are a lot of schematics to be found at Diyaudio.com and all over the web.

I think it's too tedious to learn it the proper way. Besides, you can never predict the sound of it, being an engineer or not. You have to learn by doing, and doing is a lot easier when using simulators like LTSpice.
 
Apr 24, 2009 at 6:40 PM Post #7 of 9

BlizzofOZ

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Quote:

Originally Posted by NelsonVandal /img/forum/go_quote.gif
I think it's too tedious to learn it the proper way. Besides, you can never predict the sound of it, being an engineer or not. You have to learn by doing, and doing is a lot easier when using simulators like LTSpice.


True, I agree... I'm a computer programmer by trade and I find that I cannot be taught or site through classes. I have to do... make mistakes and learn from it.

I think the trouble I'm having is converting from schematic to actual hardware.

For example:
I got my hands on an older Evil Genius electronics book. I saw a simple project where you project a sound source via a infrared LED. It is to be contained in IR type remot control, point 2 point.

I know this electronics 101, but I don't understand how the grounding is done off the IR LED.

Check out this, page 92:
http://http://books.google.com/books?id=0foFgRiIpUQC&pg=RA1-PA91&lpg=RA1-PA91&dq=evil+genius+voices+grave+schematic&source= bl&ots=IO4o7xQhJM&sig=PoDaP88HJap1DISHThrDUp0hPOA& hl=en&ei=SQbySYTVCc2LtgeiorGfDw&sa=X&oi=book_resul t&ct=result&resnum=1#PRA1-PA91,M1

How/where does the ground tie to? To me, the Audio input grd, amp legs 2 & 4 and IR LED gnd all tie together, correct? Then where does all tie/go to?
 
Apr 24, 2009 at 7:08 PM Post #8 of 9

SiBurning

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The simple answer is they all tie together. Unfortunately, grounding is part black art. You might just pick one spot and connect anything that needs to be grounded directly to that through a wire or pc board trace. Don't take shortcuts and connect two things together before going to ground. This is a star configuration, and probably a good place to start.

An alternative is suggested in the schematic. Tie the two amp grounds and the output ground--the bottom of the LED--together. This becomes a local grounding point for the high current stages. Next, pick a main grounding point where you tie all the grounding points together: the local "high current" ground, the power supply, and the input ground.

Personally, I'd start with the second. The issue is whether or not you get interference where the return currents in the "high current" stages flow back into the more sensitive input stage. You prevent that by making it much easier for the current to flow back to the power supply. You also want to keep your grounding leads short, which suggests putting that local "high current" grounding point right at the op amp grounds. The first thing I'd question if there was a problem is where to connect the power supply, and whether to place the main ground at the power supply, or possible at the op-amp ground. With "at" defined as having the shortest amount of wire to that component, and preferably no wire except for the component lead itself. A grounded case would complicate this by adding another grounded connection.
 
Apr 24, 2009 at 7:10 PM Post #9 of 9

r_d

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"Ground" is just "zero electric potential"
Electric potential is relative, so ground can be whatever you want it to be, as long as all of your voltage supply lines are defined relative to ground. In the example you provided, +9V would be the positive terminal of a 9V battery, while ground would be the negative terminal.
You need to be careful when connecting the grounds of separate systems. In an isolated, battery-driven circuit, such as this, ground loops usually aren't an issue, but if you're trying to connect several devices it's something you have to consider. A ground loop occurs when you connect two grounds with different electric potentials.
 

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