Amptweaker Defizzerator Stripboard Layout

I went to the shop yesterday hoping to buy 2 Amptweaker Defizzerators for a recording session but of course; they only had 1, so I bought 1 and reverse engineered it. it's a passive circuit so you get a bit of loss and I may work on a buffered version at a later date but for now;
enjoy.

Electret Microphone Preamp Stripboard Layout

someone asked me to do this, so I did. it's a useful little circuit to power those little electret microphones.

Quick And Dirty Laser Driver Stripboard Layout

This was just a quick little circuit I built to test all the salvaged CD/DVD lasers I have.
essentially it is a adjustable constant current power supply.

the Vin is 7.2 volts.

Simple Dual LED Battery Monitor stripboard layout

I got some 3 pin dual LEDs and I thought a good use for them is as little 9v battery status monitors for my guitar pedals. so I came up with this quick circuit that fades from green to red as the battery voltage drops (as shown in the video)

it's a good little mod circuit for any project you want to build that uses a 9 volt battery (or existing stuff you own)

Atari Punk Console Stripboard Veroboard Layout

Another quick one. A favorite among beginners - originally by Forrest Mims
I got an email this morning asking to check over a layout he'd found and also how to add a volume pot so I just did a new layout, built it and made some stupid noises for half an hour and now I'm posting it here.
this is obviously the version that is adapted to use 2 single 555 timers rather than 1 dual 556 timer but it's the same. 

have fun.

 

Op-amp +/- Power From Single Supply Fragment Stripboard Veroboard Part 2

a while ago I did a split supply circuit fragment which included a voltage follower HERE - however there are much cheaper ways of achieving split supplies for experimentation with Op-Amps and other dual supply IC's (obviously this is for low power circuits eg guitar FX development etc.)

The first example uses a Trim pot to divide the voltage which is pretty cool for biasing to favor either the positive or negative rail.

The second example is the most common type of rail splitter - cheap as buggery and does its job. in the example I've given - it will divide the voltage in half so that if you put in 9 volts you get +4.5v and -4.5v

The Third example uses Zener Diodes to give you a regulated split supply - however you do lose a volt or 2 so you need to supply them above their combined values.
eg if you use 2 5.1 volt diodes in the circuit provided - you need to supply it with 11 - 12 volts to get +5.1v and -5.1v

I shall include a table of Zener diode values at the bottom that I found in some datasheet a long time ago - unfortunately I am not sure where it came from because as usual I only saved the relevant page so if you stumble across this page and it's yours or you know whose it is - let me know so I can give you credit etc. I assume it's National Semiconductors though.

Linear PC Fan Speed Controller Stripboard Veroboard Layout

Extremely simple fan speed controller.

the input voltage depends on the fan you're using however the fan I used is a 12 volt fan so mine is powered by a 12 volt power supply.

I made this for a soldering iron fume extractor however it will work for your PC fans too and I plan on using it in mine.

here is a good video by fixitdaz on a very similar circuit

Simple LED Flasher Stripboard Veroboard Layout

I've done LED flasher type circuits before on here but usually they were for something someone wanted so they did specific things like fade in and out and so on.

So I thought for a little 10 minute project I would do one of the very first projects I ever made as a little boy. I was very proud when I made my first LED flash. it's not like now where people just load up the "blink" sketch in Arduino. this is a proper old school relaxation oscillator.
my original one had a few more components but I've managed to whittle this down to 3 resistors, 2 transistors and a capacitor + an LED obviously.

this particular circuit is known as a relaxation oscillator and there's lots of theory and stuff behind that but in extremely simple terms: it charges a capacitor until something "disturbs" it. in this case the "disturbance" is the threshold voltage of Q2 (the voltage at which the Base conducts) this quickly discharges the capacitor which results in a short blink.
which looks nicer than the conventional square wave oscillator which the LED stays on the same length of time as it is off

everyone loves a flashing LED

if you get this reference then you're ace.

White Noise Generator Stripboard Veroboard Layout

This is a very basic circuit which consists of 2 parts
1st is the noise generator which is the first transistor with no collector connection
2nd is the bit which may look more familiar which is an AC common-emitter amplifier and this is just to bring the noise upto a usable level - I have taken a scope screenshot of what the noise looks like however it is an audible sound which is pretty useful for testing guitar fx or filters and other such things.

if you wish to learn more about the common-emitter amplifier the best source for information is "The Art Of Electronics" book - on page 77 almost the exact same amplifier circuit appears with explanation 

you can of course experiment with different types of transistor in the noise section - i'm not sure how available the BC108s are now, I just happened to have a load of old ones, I hit it with a hammer to get a bit more noise out of it.

the best voltage I've found to use this at is 18volts however it does make noise at 9volts upwards

Constant Current Led Tester Stripboard Veroboard Layout

Not really much to say about this thing really except that when it is powered at it's optimum voltage (12v) it tests LEDs at about at a current you set with the 100k pot.
I made this because I have tons of LEDs in a component bin and not only did I not know if they worked but using this I can match them for brightness because I'm sick of projects looking half arsed with different brightness LEDs

The other LED based use is that when you buy lots of LEDs from a one-hung-low chinese source on eBay there can be the odd batch of crap ones and it's best to find out before you spend 4 hours troubleshooting a project only to find it was the LED that was bad.

555 Astable Timer Circuit Fragment Stripboard Veroboard Layout

I thought I would lash up a quick Astable 555 timer layout because this is one circuit that gets used a hell of alot - I certainly do. I included a little bit of math on the schematic but that's purely for the sake of it, normally I would just use a trimpot or something unless space is at a premium however even then it's not that important because you can use a trimpot/resistor substitution box to find the value required rather than doing boring mathematics.
it's always best to just try things until they work the way you need it to work otherwise you get bogged down with boring numbers.

I was also going to include the "one shot" version of the circuit because it's pretty useful when you need to convert something like a tact button press to a specific timed pulse so you don't get ghost switching but in the end I didn't, I'll save that till next time I can't think of something to do

EDIT: I just realized I made a little error on the "boring math shit" I meant to write for "t1" (R1+R2)xC1= 1.5mS
it doesn't really matter regarding the stripboard - that's fine, I just wanted to correct the little Math I do

Op-amp +/- Power From Single Supply Fragment Stripboard Veroboard

a simple little circuit that will help anyone really new to electronics. you'll see a lot of circuits that have ICs that require a split power source IE +5 volts and -5 volts, there are quite a few ways of achieving this, ranging from the full on voltage regulator method (so you have a LM317 and a LM337 with a center tap transformer) to charge pumps or you can use a voltage divider or in the case I have laid out, a voltage divider with a unity gain buffer to give you a virtual ground. basically the circuit splits the input voltage in 2 and makes a center reference point between the 2 voltages - that's the really stupid way of explaining it anyway.

for the sake of better performance (especially for you audioweirdos) I have included capacitors on the input however usually I wouldn't bother including them because I put filter caps on the main power supply but I put them on the layout for the sake of completeness.

it maybe worth noting that if you saw my headphone amplifier circuit earlier on, I used a different type of voltage divider, quite similar to this without the op-amp buffer but instead of giving me dual voltage supply, that one gives me a Vref of half the Vin.

anyway here is the circuit

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 :)

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

Mains Finder Stripboard Veroboard

a quick brutal mains finder stick thing - in close proximity to mains it will cause the LED to flash - I've used a weird type of layout in order to stick it in a tube