Step 4: Lay Out and Solder Circuit

This next step requires the most skill out of the others, namely the ability to read a schematic and the ability to solder. Both have an incredible amount of resources both on and offline, so even if you aren't the most technically minded, you should be able to learn both incredibly quick. One that I would suggest is Sparkfun's "How to Read a Schematic."

Above is the schematic used for the square wave oscillator. If you're unfamiliar with schematics, it may look daunting, but take some time reading up on schematics and you'll be able to put together this circuit rather easily.

Note that I have also included a pdf version of the schematic, in case the first one is hard to read in your browser.

If you've never soldered before, I would suggest testing out your skills on a couple of extra wires and components before you try your hand on your actual circuit.

Also, I would suggest getting a "Breadboard," which is a tool that allows you to lay out a circuit and test it before making anything permanent. The second image above is an example layout of the breadboard that will work. Because breadboards are designed to be easily changed and are for prototyping purposes only, your breadboard will probably not look exactly like the one shown here.

If you're new to breadboarding, Sparkfun.com has a really great tutorial to check out.

After you've assembled your circuit, you need to transfer it to the "Perf" Board to be permanently soldered on. Take your time with this step and make sure that all of the connections are correct and that no excess wires are touching.

When you're ready, solder all of the points, and then cut all of the excess wire off. Shown above is the Perf Board, both soldered and unsoldered.

<p>Hello everyone! I never anticipated this would become such a popular instructable! Because of its popularity, I'm going to be making some updates addressing the most common questions I've been asked.</p><p>First, I have uploaded a much nicer looking schematic, with more detailed notes on it. There is one embedded in the instructable as well as a pdf download for easier/more convenient reading.</p><p>Other planned updates:</p><p>-A fritzing diagram for the breadboard layout</p><p>-An eagle file so you can order a PCB custom made for this project!</p><p>-Information on how to get different frequency ranges</p><p>-A troubleshooting guide for some of the most common problems people have</p><p>If any of you have any suggestions for things you would like to see added/improved, please let me know!</p>
<p>Update #2!</p><p>I have just designed an eagle pcb for this, I've ordered a set and will confirm that it does what it's supposed to do, and then I'll post the eagle file, so everyone can have a nicely laid out PCB!</p>
<p>can I use a lt1019 or 1013 op amp?</p>
<p>The 1013 would work just fine, but be sure to check the pinouts so that your - and + inputs and output line up with the corresponding inputs in the schematic.</p>
<p>Hello! :) </p><p>Great tutorial! but I have tow questions. Where is the eagle file? And what kind is your perf board? Is a board that needn't design? Is better this or make my board? </p><p>Thanks in advance</p>
Just realized I haven't uploaded the eagle file - I will get that up soon!<br><br>The perf board I used in the instructable is just a general purpose general design perf board (I have a link to it to buy something similar on Newark in the &quot;gather your parts&quot; step).<br><br>The general perf board will be a bit cheaper, but you have to do a bit of design to get all the nodes to line up correctly, whereas the eagle-designed PCB is an easy way to just place your parts exactly where they need to be. The other advantage to the Eagle PCB is you can skip the breadboard part of it, and build it directly, though that's not as fun!<br><br>If you want to alter or expand the design in any way, the pre-fabbed PCBs can be restrictive depending on what exactly you want to do.<br><br>Hopefully that helps!
<p>Okey, thanks for your reply :) Another question, where I buy my components, there aren't a capacitor 0,001uF with 1600V (like your list). I can buy one of this but 630V. Is there a problem? Thanks!</p>
<p>Nope, that's a maximum voltage rating for the capacitor. the maximum possible voltage we'd see across that capacitor in this circuit is 9v, so one with a 630v rating is 100% ok!</p>
<p>Hello:)</p><p>My first project in this area, had success from the start that I attribute to the author.</p><p>cant wait for the next one.</p><p>Cheers</p><p>Steve </p>
<p>Thank you very much! Glad to hear it worked!</p>
<p>hi ! looks like a great and fun thing! im out to make one. as for the 741 op amp, i ordered this thing- </p><p><a href="http://www.taydaelectronics.com/ne5532-5532-ic-dual-low-noise-op-amp.html" rel="nofollow">http://www.taydaelectronics.com/ne5532-5532-ic-dua...</a></p><p>is it the right componenent? will it work?</p><p>thanks</p>
<p>Yep! It will work, but you'll have to change the pin numbers from my schematic, as the 5532 is a dual op amp (there's actually two of them in the package), and the 741 is a single. Here's a translation for you, with the 741 pin on the left, your 5532 pin in the middle, and the explanation of that pin on the right:</p><p>2 -&gt; 2; Negative input</p><p>3 -&gt; 3; Positive input</p><p>4 -&gt; 4; Negative rail</p><p>6 -&gt; 1; Op Amp Output</p><p>7 -&gt; 8; Positive rail</p><p>Hope that makes sense, thanks for trying it out!</p>
<p>Hello and thanks for this awesome tutorial! I'm going to make my own version of it next week (when I get the parts). Does the cable out of OP amp 5 go directly into the oscillator cable or is it connected to the frequency pot and R8? Just to be sure. I'm going to build exactly this oscillator except for that I'm going to put 5 potentiometers parallel next to each other with each a button in series, so you can play it like a piano (except more notes together won't work). Thanks for inspiring me to do this for my physics assignment and giving me this awesome tutorial!</p>
<p>I should have looked better at the breadboard schematic. I already know the answer</p>
<p>Glad you got it figured out!</p><p>Regarding the switches and frequency, as long as you're doing your calculations with the series/parallel resistors, it should work! Just note that pressing multiple switches with the resistors in parallel will cause the resistance of that leg to decrease, which actually causes the frequency to increase. So, you won't be able to &quot;play&quot; the keyboard without a lot of care being put into making sure the switches aren't pressed at the same time.</p><p>The other note I will make is that the switches, when unpressed might also have some erratic behaviour, as the oscillator may still oscillate, but at a very low frequency. I would suggest using SPDT (Single Pole, Double Throw) switches, with the second pole connecting across the oscillator output. This will &quot;Gate&quot; the oscillator off of these switches as well as change the frequency, so if none of the switches are engaged, literally nothing is coming out of the oscillator!</p><p>Hope that helps</p>
Thanks for the info. I've just got it working with one note! I'm aware that I can't play more notes at the same time but I don't know what kind of switches I have. I'm going to &quot;tune&quot; the potentiometers by putting them through my computer, so I will see low notes if that's the case
<p>Awesome! Thank you for sharing that; just what I've been looking for! I want to build a simple tone generator for syncing two multichannel sound recorders. I'd need to adapt your schematic to incorporate an extra mono output and a 'push to make' momentary switch to trigger a simple pulse tone for sync-up. I'm a bit of a noob to electronics; just a few veroboard stompbox fx layout builds and the odd guitar wiring harness under my belt. I don't suppose you could tell me the best way to incorporate a second mono output and a momentary off/on push button switch into your circuit design? </p>
<p>For the two mono outputs, you've got a couple options:</p><p>Two separate volume knobs:</p><p>On the schematic, the portion that is labeled &quot;Volume and Output Section,&quot; basically repeat that, and connect the incoming line to the same wire marked &quot;Oscillator Output&quot;</p><p>One volume knob for both outputs:</p><p>For this I would just add a secondary jack, with the sleeve connected to ground, and the tip connected to the same wire that the tip of the first jack is connected to.</p><p>For your momentary, I'd put a momentary switch in line right where it says &quot;Oscillator output.&quot; So, instead of that output going to the volume and output section, it goes to the momentary switch, and the output of that momentary switch is what goes to the volume and output sections.</p><p>Hope that helps!</p>
<p>Got it working! I couldn't find a 741 so I used 778a instead. Changes the pin out quite a bit but allows for a dual OSC. </p><p>That changed pinout tripped me up for a little bit</p>
<p>Cool! Glad you got it working! The dual oscillator could be cool if you add another pot for frequency - you could then either sum them or just mix between the two!</p>
<p>on the fritzing diagram, you have a green wire running from V- down row 22 to E. What is that doing?</p>
<p>It uh.... doesn't do anything. Good catch! I'll change that and reupload it!</p>
<p>This project was the first electronics project I've ever tried, and I managed to get it all to work the first time, so woot! I bought my supplies locally and followed the breadboard image. I couldn't match the exact circuit as my cheap breadboard only had 2 rails, so I made do. I was amazed that it worked properly the 1st time I powered it up. Thanks! My only request - if someone figures out the mod to give it more of a frequency range, that would be great. My next step is to transfer the osc into a project case so I can take my bleeps and bloops with me.</p>
<p>That's great to hear!!! I love it when somebody can complete it successfully - it really means a lot to me!</p><p>For the frequency question, I&quot;m just going to copy-paste a response I gave to a similar question below:</p><p>Using the schematics shown, you get roughly 207 to 310 hertz. What controls the frequency in this one is the 500k&Omega; variable resistor and the 1M&Omega; resistor connected to it (top center of the schematic) To achieve higher frequencies, lower the value of the 1M&Omega; resistor, and for lower frequencies, raise this resistor value. To achieve a larger sweep, get a larger valued variable resistor.</p><p>If I had to do this again (who am I kidding, I probably will!), I would change the 1M&Omega; resistor to a 300k&Omega;, and make the 500k&Omega; variable resistor a 5M&Omega; for a larger range, extending from 60Hz to 1KHz.</p><p>The math for all this is explained on this page (there's even a handy calculator at the very end if you're feeling adventurous enough to try even more values):</p><p><a href="http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/square.html" rel="nofollow">http://hyperphysics.phy-astr.gsu.edu/hbase/electro...</a></p><p>Keep blooping!</p>
<p>Hi, just wondering why there is a differing amount of resistors in the the fritzing diagram and the accompanying image of the breadboard? Also which image should I follow as Im new to all this and planned on matching what I have to the image on here to produce it that way? As well as that im wondering why the arrangement of the two images im talking about is different in terms of where the components are placed. Any help is appreciated :) cheers.</p>
<p>Im struggling to identify which resistors are which too on the fritzing diagram </p>
<p>The resistors are identified by resistor color codes. Here's a code calculator and a chart:</p><p><a href="http://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code-4-band" rel="nofollow">http://www.digikey.com/en/resources/conversion-cal...</a></p><p>As far as the differing number of resistors, I'm assuming you're referring to the 2x 10k&Omega; resistors vs. the 1x 20k&Omega; resistor? Those two are basically the same thing. 2 10k&Omega; resistors running in series just adds up to 20k&Omega;, so whether you have 2 10s or one 20, it's the same thing.</p><p>Long story short, in electronics there are multiple ways to do things yet still be what we call &quot;Electronically equivalent.&quot; It's the same idea as 4x2 is mathematically equivalent to 4 + 4.</p><p>Honestly I would go off of the schematic instead of the pictures of breadboards, as you can lay out a breadboard an infinite number of ways and still be electronically equivalent; the schematic actually defines the connections. If you don't know how to read a schematic, there are a number of great tutorials online to help you along the way. Here's one from sparkfun: https://learn.sparkfun.com/tutorials/how-to-read-a-schematic</p>
<p>hi, this is what i have so far but it isn't currently working. I replaced the speaker with a simple 1/4&quot; jack output so im not sure if its that, is there anything noticeably wrong with this breadboard layout as ive tried general trouble shooting but to no avail. Thanks in advance :)</p>
<p>Troubleshooting breadboard pictures is relatively difficult, but it just looks like there's a lot of stuff in the wrong spot. Take for instance your ground, which is the black wire coming off of those two resistors around rows 35-40; that is plugged into the positive rail of your breadboard, but nothing else is. There should be a lot going to ground. It also appears as if your 1/4&quot; jack is just plugged into the 9v + and -, which won't get you anything.</p><p>I would also recheck the pinout of the opamp, as that doesn't look entirely correct at first glance.</p>
<p>Your not wrong they are haha. Ive decided to start over using the fritzing diagram as a guide. The result was the same though unfortunately, this is it at the minute, same rule goes I haven't got a clue as to whats wrong with it. Im starting to understand the basics of schematics but need to complete this for a uni project so worry I wont have time. Also do the numbers shown on my breadboard differ from yours and the fritzing for any particular reason? Again, your help is much appreciated!</p>
<p>That looks much better! I can't completely tell in the picture, but that 1M&Omega; resistor looks like it might be going into pin 3 or 4, when it should be going into pin 2. Might be just the angle of the picture.</p><p>What I would do next is bypass all of the output management stuff. So take the positive/tip output of your 1/4&quot; jack and put it directly at pin 6. There you should get the square wave without any attenuation. The next thing to check is to make sure that your power supply is actually spitting out 9 volts. Hopefully you have a voltmeter or something of the sort. (Or just make sure your LED is lighting!). The last thing is you may have blown the op amp - which is not difficult to do.</p><p>Hopefully something in there helps!</p>
<p>Hi I got the breadboard set-up working and moved on to the perfboard. This is what I have so far but im finding it hard to understand where the pots and output are on the board from the schematics. Is there any chance anyone could give me a hand in identifying where they should go on the images ive uploaded? Id really appreciate any help, cheers :) </p>
<p>Ahh good, ill look in to getting a few more op amps then to make sure. Ive gone back over everything in relation to the fritzing and it all seems exactly the same but the LED wont light on the breadboard (but will if i just connect the +/- wires of my 9v battery) so I can only assume then that its the op amp. Thank you your a great help :) Ive uploaded a more detailed picture too just to re-confirm that its all right, cheers :)</p>
<p>Thanks for the help its much appreciated :)</p>
<p>No problem! Let me know how it goes/if you have any other issues!</p>
<p>Hi, just wondering why there is a differing amount of resistors in the the fritzing diagram and the accompanying image of the breadboard? Also which image should I follow as Im new to all this and planned on matching what I have to the image on here to produce it that way? As well as that im wondering why the arrangement of the two images im talking about is different in terms of where the components are placed. Any help is appreciated :) cheers.</p>
<p>hey guys! i just finished this project and it works like a charm... i just modified it to get larger frequency range.</p><p>Many thanks for the schematics ;)</p><p>And I was just wondering if it would be possible to build two oscillators with the same power supply and connect both outputs on the same jack out to get two different frequencies? :)<br>tnx</p>
<p>Awesome! Glad the project worked for you!</p><p>And totally with the two oscillators, single PSU, just connect all the gnd, +9v, +4.5 and -4.5v nodes together!</p><p>As far as mixing them goes, I would suggest altering the volume output portion to include an active summing mixer:</p><p><a href="http://electronicdesign.com/ideas-design/efficiently-design-op-amp-summer-circuit" rel="nofollow">http://electronicdesign.com/ideas-design/efficient...</a></p><p>That page should be a good start - let me know if you have more questions!</p>
<p>hey, after a cuple days i finally got some time to spare and started the mission... again :). </p><p>i tried building another oscillator on the same breadboard and just connected the outputs, but the effect was that at some pot position oscillator stops working, and quite some frequencies just jump from one to another while turning the pots. it was just a quick test...</p><p>thanks for the link, i'll read it and study it ;). its just that i dont have much of a electronic background and some of this things are quite new to me :). but hey, i got to start somewhere, right? :)</p>
<p>You mean put both of the outputs together without another summing amplifier in place? That will probably cause some strange things to happen!</p>
<p>so i need 3 op amps in total then? two 741s to generate different frequencies and the third one for summing? </p>
<p>Yep!</p><p>If you're getting yourself into electronics, I'd suggest buying about 25 of these from the get go. They're one of the most common components in electronics, and they're pretty easy to fry.</p>
<p>ok, will buy them tomorrow... can you just tell me which one to buy, or is 741 also good for summing?</p><p>thanks</p>
<p>741 is great for summing!</p>
<p>ok, here's the thing. I have two separated square wave oscillators on my breadboard each one working like a charm for itself. i put the third 741 on there to sum the two frequencies (non inverting mode)... i connected the two outputs each over a 10k resistor to '-', grounded the '+' and added additional 10k resistor connecting '-' and 'out' of the summing amp. out comes something strange (like if just the two outputs of the oscillators were connected together). If i remove the resistors, leaving just the one connecting the '-' and 'out', (assuming that the frequencies pots does their work) and connect the outputs directly to '-' it works, but both oscillators work as one. the higher frequency pot prevails and out comes just the frequency of that oscillator...</p><p>i hope its not too confusing, and thanks for helping out ;)</p>
<p>I believe you got your + and - flipped to go with a non-inverting summing amplifier.</p><p>You doing something like this?</p>
Yep, thats the thing... Is this the right way to do it? oh, i got myself confused with the symbols, i got it right on my board. My bad...
<p>That should work. I will say to make sure your resistors in that portion of the circuit are sufficiently large so they don't alter the impedance of the frequency circuit too much.</p><p>I will also add that I haven't tried this myself, but can within the next few weeks to verify that this will work.</p>
<p>if you'd be so kind to verify this i would very much appreciate it... I'm probably just missing something, but it would be nice to know if it works for sure... </p><p>Do you maybe know any good sine wave oscillator schematics?</p><p>The thing i want to do is to combine three oscillators, each one connected to an on/off and sine/square switch, in one box, one power supply and one output. And a volume pot for each one of course :). i know its a little bit of a long shot but why not try, eh? :)</p><p>many thanks!</p>
<p>ohh, and another question... is there any way to get even lower frequencies?</p><p>tnx ;)</p>

About This Instructable


247 favorites


More by dnhushak: Build a Square Wave Oscillator - Part 1 of DIY Modular Synths
Add instructable to: