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.

 

Battery Simulator With Voltage Sag And Bar LED Indicator Stripboard Veroboard Layout

This is sort of a request - I was asked if I had a layout for the KAT Deacy Amp Battery Simulator which of course I don't but I thought "it can't be that hard to design one"
the KAT one has a "voltage sag" control on it to simulate the various battery discharge states so I designed that into it as well.
I thought however; I would go one step further though and include a battery state monitor too which is configured to show the working voltage of a 9 volt battery.

I thought it would be a good idea to do this little project because it has many uses outside of the Deacy amp - you can of course use it to sag the voltage of any 9 volt device such as guitar FX pedals which I know people like to do.

As you can see - I tested this using my constant current load set at 100mA and even pushed it to 200mA but I didn't want to go too far because I couldn't be bothered to find a heatsink. you can get upto 1.5 Amps if you use a decent heatsink.

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

Acoustic Probe / Electronic Stethoscope ( based on Robert Penfold Design ) Stripboard Veroboard Layout

I was trying to track down a noisy inductor (I like to call them a squealer) in the back of a monitor so I thought I would design a electronic stethoscope - then I remembered I had one from something I built from Robert Penfolds article in a practical electronics (silicon chip magazine for people in other countries) magazine in my youth. so I checked my box o'junk and found that I had salvaged parts from it.
So I made myself a new stripboard layout and built a new one. I had to change the odd part cause the original called for stuff that costs stupid money by opportunist eBayers.
But it works a lot better than the old one ever did - so hurray for opportunists I guess.

I use this to drive a pair of in-ear headphones and it really does work really dam well. so if you need something to track down the source of noise or spy on people through the wall or something - this is for you.

NB: if it's a bit too hissy for you - you can remedy that by putting a 1n capacitor in parallel with R6