Logic Probe Stripboard Veroboard

quite a simple and boring little thing, but an extremely useful bit of test gear so I urge you to build it. I actually laid out the veroboard to fit inside the little tin in the picture, I had envisioned it looking a lot better than it does but I am quite frankly shit at enclosures whether they are old mint tins or proper ones from the shop.

when you've built up this circuit, to use it you connect the power clips to the power of the circuit you're testing and probe the logic outputs. 

you'll notice that when you power it up and the probe is not touching a test point all the LEDs are lit up, once it detects the actual logic level the LED (high or low depending on the logic output) will light up and the others will go out.

Stepper Motor Controller Stripboard Veroboard

This weeks entry is a stepper motor driver. you will notice this has 4 LEDs on the board, this is to stop flyback current from damaging the other semi conductors, they are necessary so don't omit them + you could maybe mount them on a control panel cause the flickering looks cool.

when I made this circuit I used a motor I ripped out of an old HP deskjet so I used the colour code on the wires on the board layout so I have included a stepper motor diagram that shows where the wires actually go so you can use any stepper motor

similar NPN transistors can be used - I just have loads of BC549s


NOTE: pin 14 of the CD4013 is connected to the 12v rail

it is moving, it's just kind of hard to capture the act of movement in a still picture, still kudos to my phone camera for not blurring on movement.

Resistor Substitution Box

I built this after finding some cool push wheel edge switches on eBay from a really cheap Chinese seller, I honestly thought they would be crap but over a year later it is still working as new.
to make it as accurate as possible I measured each resistor with my just calibrated Fluke 87 III on hi-res mode and my old Fluke 77 for second opinions sake. so that it isn't just in a tolerance - it is exact and I also got resistors that change value as little as possible over temperature ranges. I know things don't need to be that accurate but I'm a bit weird that way. it's kind of a "confidence in your tools" thing.

anyway although I've tried to get pictures of how I made this thing with a crudely drawn picture, I'm not sure if it's clear as to how I did it.

Also it's probably worth me mentioning that with each decade you use the resistor value you're multiplying by
so the first one (on the right) is 10 1ohm resistors, the next one is 10 10ohm resistors, next 10 100ohm resistors and so on.
feel free to comment and ask for any further help should you need it.

Simple Forward/Reverse Motor Controller Stripboard Veroboard

this is a pretty simple build, I needed something to control a motors speed and direction with just one potentiometer so I came up with this - essentially it is 2 555 timers bridged together so that when you turn the pot one way the frequency on the first one increases and the second decreases and vice versa - it outputs a PWM signal so you may need to use a smoothing capacitor on the Motor (non polarized of course)
when the pot reaches the center position it will stop.
I'm sure this will have many more uses too.

Headphone Amplifier Stripboard Veroboard

I haven't experimented too much with this, I just needed something as small as possible based around a Class AB headphone amplifier IC I found in an old TV that would pretty much compensate for the crappy volume limit that Apple have implemented on their iPods (as mentioned in the Apple Rant blog earlier)
and I'm sorry Chu Moy - your op-amp based buffer type headphone amp just doesn't cut the mustard for me.
the datasheet for this IC claims a THD of 0.001% so if that's your thing - power to you.
and a S/N ratio of 110dB
however the thing that interested me the most is that it's pretty low on current usage which maxes at about 7mA under load and around 3-5mA quiescent. I desoldered a 3v lithium battery holder from an old PC motherboard and used a lithium battery as the power source. but I'm sure 2 AA's or AAA's will work fine.
originally I was going to power it via a 9v/5v regulator method but I thought it would be a pain in the arse when carrying it around in my pocket. 
I may do some scope captures at some point but until then - this thing works great.
 
Since everyone feels the need to disclaim liabilities I shall do the same. If you build this and listen to music too loud and you damage your hearing, it's your own fault. 

Testing to see if it works - it does!

LM317 Fragment Stripboard Veroboard

I often make power supplies for whatever project I design and the simplest and cheapest way is to buy in loads of LM317s (or salvage them or their pin compatible lower current 1117 counterparts) and use a couple of resistors to set the voltage you need rather than having to buy a load of separate value voltage regulators.
you can always just set the voltage with a trim pot but that's messy so we can use a simple equation to get the value needed, but since no one can be arsed to do equations - even simple ones - I have listed values  of voltages I have commonly used.
if you don't have the right value resistor - don't be afraid to make resistor tipis or resistor canoes (series or parallel) to get the right value - every good project has a tipi/canoe in it :)

Experimental Class D Amplifier Stripboard Veroboard

the reason this is qualified as "experimental" is because it does work but I haven't found a use for it yet. I designed this primarily to see how well the 555 timer IC would reliably create the PWM at high enough frequencies for audio. I haven't done much testing other than a quick check with a signal generator/speaker to see if it worked and of course a few passes with an oscilloscope to make sure things were doing what they were meant to be doing. I used a LF351 op-amp pretty much because it was the nearest wideband op-amp to me. I often try to explain that the reason I choose certain ICs is not because they have some magical "warm" sound or any of the other shit audiophiles make up but because I have looked at the datasheet and determined it's the best part for the job based on the explained data within the data sheet, either that or I'm lazy and I know a specific one within arms reach will work.

this kind of amplifier requires an inductor, a value I didn't have to hand so I used some salvaged enameled copper wire from the secondary of a burned out mains transformer (24AWG if you need a wire size)
to make the inductor I wrapped 70 turns around a bolt from my massive box of all the screws I've collected over the years salvaging stuff, the bolt is about 5mm in diameter.and that will get you in the ballpark of 470uH I think mine ended up being 500uH ish.

anyway I will draw up the schematic maybe tomorrow but for now here is the veroboard layout

My Apple iPod Rant

So no one can accuse me of just being an Apple hater I have posted a picture of the 2 iPod classics I own - why do I own 2? cause I have shitloads of music.
I don't give much of a shit about the physical design of these things - they look like little rectangle pods and there's not much more you can say about that.

being into electronics and also having owned a lot of these things - I have taken these apart, made frankenstein iPods from bits of lots of broken ones and so on, electronically I do love the circuitry involved in them and the engineers who designed them are obviously extremely talented.
   
With that said certain things really annoy the hell out of me and it's more to do with the operating system on these devices - first of all there was a really idiotic decision to limit the output volume in retaliation to lawsuits filed by morons who didn't realize that if you listen to sound too loud it could damage your hearing.DICKHEAD

"so why is this a problem then?" I hear you ask, "surely you don't want to damage your hearing" no, I don't but there are quite a few genres that play music very quietly - I'm a big fan of sigur ros for example and when the sound of a car in the distance completely drowns out the entirety of the music you are listening to then what is the use of even having an iPod in the first place?

I don't get why putting a disclaimer on the box saying something to the tune of "if you listen to loud music for  too long you will damage your hearing and you are also a moron - we are not liable" isn't enough, it's enough for smoking and everything else.

This is precisely why I hate people who file lawsuits, they don't realize that their short term ambition to extract money for nothing because they were injured by their own idiocy will be paid in some form by someone and in this case the people footing the bill is people like me who now have had the option of being able to hear what we are listening to taken away from us.

so I know that the limit wasn't initially Apples fault but they backed down to prevent further law suits, they put in that limit which makes me think that Steve Jobs' vision of not having sniveling lawyer types running his company has been betrayed.
   
my second issue is the equalizer on the iPod, this is basically a list of selectable presets with no user definable option which is just bullshit, I would guess that not bothering with the presets and just having the ability to make your own presets and save them would have taken a lot less time to code than the current method.

the nearest preset that makes the sound how I want is the "bass booster" preset and that is by no means anywhere near what I want, it distorts the low end too much which just suggests that the people coding these presets didn't take into account that music is mastered at different levels. If there was a user definable EQ I could compensate for this oversight, you know - like every single other digital music player has - even a lot of the old analogue portable music players had this feature, only one hung low shit things had presets minus the user definable EQ.

I think my main gripe concluded is that I want to at least have the illusion of control in what I do, I want to be able to turn my music up so I can hear it and I want to be able to change the EQ abit.

Apple are the ones most guilty of trying to make everything completely idiot proof and I really don't think we should allow anyone to do that because there are too many idiots on this planet. I just don't think they should be rewarded by being given things that were technologically more advanced than a space shuttle that even they can figure out how to use by engaging just 2 brain cells.

TDA2030 Based Amplifier Stripboard Veroboard

I needed a little boxed amplifier to power a 4 x 12" cab for studio use so I came up with this little thing, it works well. because I wanted to have a battery powered ability to it I used the OPA134 opamp because it draws stupidally low quiescent current, in fact it draws barely any current when you're hitting it with signal either. I'm not one of those dickheads who thinks that putting a Burr Brown op-amp in a tube screamer in place of the 4558 that comes in it will sound better - it's an overdrive pedal if there is any difference it will be gain not "clarity" "warmth" and any of that other Audiowank people talk about.
Anyway this thing is pretty cool - IT NEEDS A HEAT SINK!
The reason I chose this specific IC (TDA2030) is because it was in just about every broken thing with an amplifier built into it in my junk shed - there were 3 in 1 TV - 6 in another, 6 in just one of the old cheap shit surround sound system things so it made sense to just use a salvage part since I have loads of them.
I'm not sure if it is pin compatible with higher wattage types like the TDA2050 etc. but maybe I'll look into that at a later date.
I'll include my hand drawn schematic and update it when I can be bothered to draw it in EAGLE anyway here you go

My bands albums;
Double Negative - The Day The Dark Won
Double Negative - When We're Gone
Digital Versions

Sound Sample

Full Schematic

This is the layout including the power supply stage

my brutal transformer shielding, it buzzed a bit with a high gain distortion before it but the shielding sorted it out completely

The "In The Lab" Part

I always like seeing peoples workspaces so I thought I would post a picture of mine.I'm always on the lookout for interesting electronic equipment, most of which is elsewhere - the things you can see are the things I use most.

The Shed (a rant)
I also took a picture of the junk shed - this is where everything that doesn't work, that people have given me goes until I need a part from said item. the reason there is a polite sign to potential thieving bastards on my shed is because a few years ago some twat broke in about 3 times because the allure of electronic stuff he/they could sell for drugs was too tempting, I actually ended up constructing a nail board, it was a flat plank of wooden flooring with about 50 3" nails sticking up out of it, my reasoning being that everytime my shed was broken into it was dark and I would gain at least a little payback for the inconvenience of reattaching my goddam shed door everytime they came back, my plan worked, the next time they broke into my shed there was a very loud scream, needless to say nothing was stolen and they never returned after that.
people kept saying that I would get into trouble if I left my little bed of nails and someone stood on it but I maintain, I have the right to keep anything within the law inside my shed (nails are not illegal and nor is flooring)  and if someone happens to go into that locked shed there may happen to be a bed of nails that I keep on the floor inside my locked shed, either way no police came around to arrest me - they didn't come around when I reported for the 4th time some bastard was breaking into my property either.

my shit attempt at mixing 3 pictures together to get the whole thing in shot

Hameg dual function generator and ATTEN scope

lots and lots of cool circuit boards in these boxes

the sign reads: dear no-user robbing bastards, all items in this shed are broken and not worth anything - FUCK OFF

the rusty nail is rusty cause the guys blood made it go rusty.

DC 0-19.99V Blue LCD Digital Volt Panel Meter Voltmeter Review

Originally this had a glowing report, it worked well and was accurate - the original one was broken and so they sent me a new one HOWEVER
once I got the new one, I did this review and put it in a box for use at a later date.
After someone got in touch with me asking me for the connections (they don't provide them) I thought I would get it out so I could let them know.

The LED backlight lit up, then nothing else happened - I triple checked everything and still nothing.
so about 7 months stuck in a box waiting to be used has some way made it stop working.
the box was not thrown,dropped or mistreated - it was an ESD safe container. So I am going to contact the seller (who I linked below this) let them know it's shit and give them opportunity to explain - 2 failing through no fault of my own is completely unacceptable.  
 HERE

Klon Centaur Stripboard Veroboard

this is one of those very subtle overdrive pedals which from what I can hear when I use it has a HF exciter - I could be way off on that but, that's what I hear. nevertheless it's a nice overdrive

FET line buffer Stripboard Veroboard

Just a quick JFET buffer I made for my guitar for use with long stage leads, nothing special but very useful

The Amp Hour Podcast

a brief moment away from veroboards and such
if you're interested in electronics based chat - this is a fantastic online radioshow
hosted by Chris Gammell and Dave L. Jones (mentioned in this blog a couple of times)
The Amp Hour  



of course there is a personal gain for me to promote this (other than the fact I like the show and think everyone should listen to it - and everyone feels warm and fuzzy when they are listened to) since episode 76 they have used the theme tune that I wrote for them
you can hear the full song here

Stun Gun Stripboard Veroboard

here is the usual bollocks : this is probably illegal, it's also dangerous and if you use it on an animal I will track you down and have you castrated. I have a lot of issues with fear and I feel unsafe a lot of the time so I made this in order to have a piece of mind, I electrocuted myself with it and it certainly made me think twice about attacking me again

seriously don't be a dick.

70dB gain LM386 Amplifier Stripboard Veroboard

it always bores me when I see people use this IC, only because everyone does but I played around and got abit more gain out of it - so here you go.