Dual LED 3PDT Stomp switch daughterboard PCB layout

I haven't done stripboard construction for a long time, truth is I've been busy with my engineering work, my bands and my mixing work to sit down and do stripboards but I've been doing PCB layouts for little projects and I thought I might aswell post them here

first of all is this little daughter-board for your guitar fx builds that will change a dual colour LED from red to green depending on the switch state; so you can use it as some kind of channel indicator or simply just have a LED to say whether the pedal is engaged or not

here is a link to the rar of the .PDF files (the only way I can seem to get boards to print at the right size) http://www.mediafire.com/file/aszhtwj0vd9xcc0/Stomp.rar/file

Here it is in a pedal I made years ago (https://paulinthelab.blogspot.com/2014/06/green-wizard-guitar-overdrive.html)

Guitar FX Switching Diagrams

I keep getting requests to do some diagrams on how to wire up guitar FX circuits so I've done the ones I use.

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)

Drone Synth Fragments Stripboard Layouts

I was initially doing this little project for myself and it was based purely on the devils triangle drone I made a couple of years ago - can be found HERE
but this project uses 6 drones and push to make switches so it makes a rudimentary keyboard.

This was totally a personal project but since I planned out the little sections on stripboard before starting I thought I would provide those fragment pieces here

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.

Adjustable Mains Hum Notch Filter Stripboard Veroboard Layout

I built this for those of you who have guitars with single coil pickups or indeed anything that picks up mains interference up (that annoying set of speakers in my bed room for example) anyway this little device reduces the mains hum by several orders of magnitude

it is adjustable between 45Hz and 90Hz so just put it before your amp or whatever and adjust the trim pot till the hum goes away.

it uses the same Texas Instruments TLC071 OP-AMP as I used in the last project for pretty much the same reason

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.

Floating Power Supply For DVM Panel Meters Stripboard Veroboard Layout

this was another one done out of necessity really.
I needed to power a panel meter from the same supply as I was measuring.
I actually didn't have the meter to test it with however it powered a cheap Digital Multimeter which I imagine takes up more current than a panel meter.
I also tried to make it small enough to be glued onto the back of the panel meter. 

6 Tact Switch Debounce Veroboard Stripboard Layout

This is one of those boring circuits which you need to know when dealing with CMOS circuits and I imagine it would come in useful for those of you using microcontrollers like Arduino/PIC etc.

using this circuit you get a nice clean switch signal from a mechanical switch avoiding miss-switching

2 channels of the switches in action

PWM LED Dimmer Stripboard VeroBoard Layout (Orig. By Dave L. Jones)

Dave Jones did a cool little circuit using a 555 to dim the LEDs on his Mantis microscope. Obviously this little circuit has a lot of uses so I thought I would make a little stripboard layout for it.

There isn't much to say about it as it has already been covered in his video (linked below)

so here you go.

 

Low Battery Indicator ( 9v ) Stripboard Veroboard Layout

I was in the middle of designing a little 9volt battery operated music thing and I thought it would be nice to have a little battery indicator to tell me when it was getting low.
Once I made it up I thought it might be a cool little thing to share on here so you could add it into stuff like guitar FX and so on.

it has 3 states:
1. if the battery is good then the LED doesn't light
2. between 7.5v and 6.4v the LED flashes to warn you it's getting low
3. below 6.4v the LED stays lit

I know there are specific ICs for this purpose however I like making my own "solutions"
Anyway hope you like it.

Linear - Log etc. Potentiometer Conversion

sometimes it's not always possible to get the response you want from an existing potentiometer and sometimes like me, you don't want to have to keep buying loads of different types of potentiometer
or you're just too lazy to reach upto the draw with the log pots in and the linear ones are nearer, whatever the reason you can alter the response curve using the following schematics - I didn't bother doing a stripboard layout for these because it's pretty much 1 or 2 resistors - I tend to use resistors the same value or higher than the pot value however you can bias the curve response to one side or the other using lower values that the pot.

anyway experiment until it does the right thing, that's the best way

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

LED Ring Oscillator Stripboard Veroboard Layout

This was kind of a rush thing I did today because I have a few projects awaiting various IC's which I can't publish yet but I haven't posted anything this week so I thought I would lash up a LED Ring Oscillator - I'm sure you've seen these things on the net in various guises, mine has increasing value resistors which basically makes the oscillator more predictable in the way it rotates and which LED starts first which was quite important for this as it's going to be part of a LED/LDR circuit

you'll notice that the schematic I've done isn't in my usual notebook format but instead I used a program from the CD off the front of a magazine called circuit wizard - it's okay for testing little circuits like this so I thought I would just upload the schematic I drew in that

anyway as usual the stripboard has been built up and it works - the rate is voltage controlled so the less voltage you feed into it the slowed the LEDs will light up - my favorite voltage is about 3.3v which is cool for uController projects that already have that voltage available - I've tested mine upto 16 volts but I couldn't go any further due to the capacitors I was using.

 

Simple Sweep Generator Stripboard Layout

A very simple Sweep Generator - it goes through the audible (and beyond) range which is useful for Impulse Response recording and other stuff of course.
it also kind of sounds like one of those woop sirens from sci fi films

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

LM3914 Voltage Monitor Stripboard Veroboard Layout

This is pretty much a datasheet circuit that I put onto stripboard
it has a monitor LED that turns off when it drops below 8 volts however by changing the placement of the resistor you can make the LED go out at any voltage for example if moved the resistor leg from pin 12 on the IC to pin 14 on the IC the LED would turn off when it drops below 5volts

Nintendetar Add-On Oscillator Veroboard Stripboard

one of the first things I made in order to sell was the Nintendetar guitar effect, this basically reshapes an input signal as PWM - it has proven reasonably successful though not successful enough to sell out of them!
anyway I have always been meaning to design a little add-on for it to make it more animated and finally I have done. Rather than redo the whole board and annoy everyone who bought the original I thought I would make a little stripboard add on daughter board so anyone that already has one can just add the board to their existing nintendetar effect.Here is a little song I did with the nintendetar to just show what it was good for Nintendetar Full song

the tricky part was getting rid of oscillator "ticks" which I managed with the aid of my resistor sub box (build one!) and getting the right rate range which turns out to be best between 0.3Hz and 4Hz ish - this particular oscillator is a Triangle one however you can also get some cool effects inputting different signals - a fast 10 - 20Hz squarewave for example give you a good stutter type effect

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