20 Second Handwashing Timer (for Covid-19) stripboard layout

quite a simple project, during the Covid-19 coronavirus outbreak, one of the pieces of advice we've been given is to wash our hands for 20 seconds. so here's a timer circuit to help you do that.

"sw" is a push-to-make momentary switch, once you press the button, the LED illuminates for about 25 seconds (I added a few seconds to the timer to allow time to put soap on your hands). then just wash your hands till the LED goes off.
pretty good way to make sure your kids are washing their hands for long enough.

Stay safe.

    before it was deployed to the bathroom

Ellas Stylophone Stripboard Layout

I have a 2 year old niece called Ella and I wanted to make her something - so I thought I would make her a Stylophone.

NB: there were a couple of errors due to me somehow pressing the "up" button in "DIY layout editor" after I had built this but before I had rendered the image. these errors have been corrected

the original error was; the "tuning board" was listed as being connect to pin8 of IC2 - however it should be connected to pin 7 of IC2
I also missed out "R4" in the schematic (cause I drew the schematic after building it)

Me and Ella

Loud Beeper LM386 Stripboard Veroboard Layout

My gran is ill and is staying with me so I wanted to make a little but loud alert beeper in case she's not well in the night and needs to get my attention.
I just roughly followed the schematic from the LM386 datasheet HERE for the squarewave oscillator

I used a little laptop speaker and it works very well. remember - the bigger the speaker - the louder it will be.

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

Dark Activated LED Flasher Striboard Veroboard Layout

Around here we get the odd brown out because the local transformer station is inadequate and hasn't been updated since the 50's so obviously it can't handle the fact that houses have more than one electrical appliance. anyway I made this low power device to be put with my torch so I can find it when all the lights go off.

after you build it - you adjust VR1 so that the LED blinks when it's dark and it should last quite a while with 2 1.5v batteries powering it.
try and get the lowest power LED you can find - remember, it will also blink all night.

Logic Pulse Generator - Logic Pulser Stripboard Veroboard Layout

Often with projects that uses Logic devices such as previous projects like the devils drone sequencer or the Sound Activated Dancing LEDs you need to create a clock signal to make the logic transition from one state to the other. you don't want to have to deal with the clock (or oscillator) part of the circuit in the experimentation stage so you need something that is capable of creating a clock signal. This is just that piece of test gear.

it also uses the same power supply you're using to power the Logic ICs in question.

here is an example of a commercial version http://uk.rs-online.com/web/p/needle-point-probes/5375163/?origin=PSF_437277|alt

aswell as the layout and schematic - I have included some oscilloscope pictures of what it actually does.

Sorry if my explanation is a little off today in the making sense department - I am suffering from cluster migraines and one of the symptoms is Aphasia. the important thing is that the actual layout and circuit are correct - which as you can see - is the case!

As you can see I have soldered a nail to the pulse output - I've found this is the ideal probe

Devils Drone Sequencer Veroboard Stripboard Layout

This has taken some time to design and it's not perfect but it sounds pretty cool (As you can hear from the sample) it follows on from the devils triangle I did earlier this year ( Found HERE and no you don't have to build that to make this work!)
This is quite a big project and as you can hear I have built it using the stripboard layout provided (as I do with all my layouts) so take your time because I really can't spend lots of time answering why things don't work. The truth is that unless you have the board in front of you there is no possible way to troubleshoot things. But if you take it slowly it should be good.
also don't forget to check out the "tips and troubleshooting" page above

I would also recommend not to do this if you're in-experienced

Poor Mans Audio Signal Generator Stripboard Veroboard Layout

this is something I made in school 15 odd years ago. you had to take a square wave, use a passive filter network to convert the signal to triangle and sine - this also has square and integrator waveforms. it's quite good up to 1 KHz but after that it starts to clip and go funny but it's more than adequate as an extremely cheap audio signal generator using 2 transistors and 1 LM555 timer IC - if you've gone through alot of my projects you'll notice how useful this IC is by now.

I have done another signal generator project that uses a proprietary ICL8038 IC Project can be found HERE which is more fully featured as far as project function generators go but the IC can be costly in certain places where as you can go on the grey market (IE eBay china sellers) and pick up hundreds of them for next to nothing.

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.

Nintendetar Guitar Fuzz Stripboard Veroboard Layout

This is something I made a long long time ago and subsequently made actual PCBs for which I still have but due to the fact my agoraphobia has reached such levels I can't post them anymore so I don't bother selling them. however it's a cool effect so I made a stripboard for it. I also Made an Add-on board a while back located HERE

or with the Oscillator Add On..

LED Crossfader Stripboard Veroboard Layout

This was a request I got via email, they wanted the LEDs to fade in and out to mimic some aircraft lights rather than just turn on and off so I came up with this little circuit. he also wanted it to run from 12 volts - so it does.
I was going to use an op-amp at first but I thought a 555 would yield a more consistent result 

Signal Injector / Tracer Stripboard Veroboard Layout

A quick but very useful project. I "designed" (I say designed, it's just a simple astable multivibrator with a basic transistor amplifier) 10 minutes last night and built it this morning basically to help fault find because I'm sick of having to fire up the function generator/scope when I just need a quick tester.
so as usual I will share it with you people.

Behringer UV300 Rate Mod (Slow Down)

I thought I'd take a quick venture into modifying a effects pedal. The one I chose was the Behringer UV300 ( Ultra Vibrato ) I love Behringer gear and in most cases they do a really good job at effects and pretty well everything they put their minds to (see the X3!)
anyway I bought this on a whim cause it was very very cheap, I didn't even bother looking for samples because if I'm honest there is only so many times one can watch people doing out of tune covers of Lucy In The Sky With Diamonds while reviewing Vibrato pedals - also they never turn the rate down to nothing to show you how slow it goes.

as you can probably tell by this post, the "rate" didn't go as slow as I wanted, I like that sort of hypnotic warped record vibrato which this pedal couldn't do however with a little knowledge of how oscillators work and a bit of time probing around with a scope I was able to modify this to go slow enough

In order to slow down the range of the Rate control you basically just have to add capacitors in parallel with C12 and C15 - or you can swap them completely for higher values - the higher you go the slower it is however you need whatever capacitors you add to be very close in value to each other because if one is very different you get an uneven vibrato.
anyway here are the pictures.

if you have any questions - ask!

and you don't need to rehouse behringer pedals, the plastic is very strong - it easily withstands being dropped down stone stairs many times.

solder very quickly otherwise you'll be resoldering SMD stuff!

it's a good idea to do this in order to tailor it to your preference

the part of the circuit I am changing

The Behringer UV300 with its nice new switch

Devils Triangle Drone Synth Stripboard Veroboard Layout

this is a project based largely on the put up or shut up mentality, for quite some time I've been getting annoyed at seeing youtube videos of people pissing about with these "synths" which are basically boxes of 555 timers with a million knobs that make stupid noises that you couldn't ever actually use in music so I thought I would make my own little synth that would get repeatable sounds and be useful in music and what better type of synth? a droner type - basically cause I love bagpipes - I like drones
anyway the circuit itself is quite a simple one basically because I only designed it during the week, all it is really is 3 triangle wave generators configured to operate in the audio range going into a mixer op-amp configuration with the odd filter here and there to soften the waveforms
I've used LM358 op-amps cause they are the cheapest, I'm not too sure if others would work in the same way though they probably will.

why call it the devils triangle - well it has 3 oscillators one of which can oscillate a slightly high pitch range (for melody) it also sounds demonic so the name fit

Hope you enjoy

EDIT: I replaced the level knobs with on/off switches - it makes it so much more versatile being able to silent certain drones 
EDIT: I added a little schematic on how the switches should be wired as it was causing a bit of confusion.

the one I made - with a really shit paint job

Fading LEDs / Eyes for Halloween decorations stripboard veroboard layout

The inspiration for this little circuit with Halloween approaching was a post I saw made on this Thrifty Crafty Girl
basically the girl had an idea of putting glow sticks in toilet rolls with eyes cut out to leave in bushes however I thought it would be cool to add an electronic element to it.
so I made a little circuit that will make LEDs fade in and out - they will go in and out of sync and will look pretty dam creepy
Anyway this one quite cheap to make circuit will "power" 4 toilet roll monsters - 2 LEDs per toilet roll or whatever you want to put "eyes" or LEDs in
below is a video of it in action

Paul in the
Lab is here to help
Everyone that's into electronics
Always feel free to
Seek my advice
Either using the
Contact button or my email
Lately I am always at the computer because
I am  designing stuff for the site though I did buy a new
Camera recently it's pretty cool. I remember the first thing I built was the
Knight rider LED scanner which I uploaded
To the site a few days ago, remember if you need to know
How to do something
Even if you think it's
Abit of a stupid question just ask, I
Don't mind. We all had to
Start somewhere. 

Knight Rider Kitt / Cylon LED Sequencer Stripboard Veroboard Layout

This is a cool little project I've been meaning to do for a long time. One which was so simple I kept putting it off.
Essentially this is a 8Hz (ish) squarewave generator attached to a decade counter - it counts upwards displaying each count on the next LED however the outputs are wired in such a way that instead of just going upwards it goes back downwards. it should be obvious when you look at the schematic how the thing works.

Anyway as the name suggests the LEDS go back and forth like the eye things on Cylons from battlestar galactica or the front panel on the car from knightrider. my older brother drives a taxi so I plan on using this to drive relays to big lamps and attach it to his car when he's next away.

This circuit is very useful outside of replicating old TV show LED things, you can use it to sequence pretty much anything using relays or even digital circuits and you don't have to use the 555 to do it automatically, you can replace that with a push switch circuit to the CD4017 Clock pin (14) and control a pedalboard for example
or maybe even make your house seem haunted by using it to remotely control appliances. I will include a simple Relay Driver below.

 

To use the CD4017 to drive a relay

Mosquito Repellent Stripboard Veroboard Layout

I'm pretty ill at the moment and I didn't want to really get up let alone make a circuit however the reason I am ill is because of bastard mosquitos - you see they bite you and your body reacts to the bites as it would a virus and with an illness the actual feeling of being ill is your body attacking the illness. in most people this reaction lasts a very short time and you don't notice it however with me any illness I get prolonged reactions, I always have which is why I feel really ill right now.
So in order to stop it happening again I thought I would make an electronic mosquito repellent

it mimics the sound the pregnant female mosquito makes which warns others to stay away.