Drive Safe for Christmas

There was an accident this morning quite close to where I work. Both occupants died.

All I can say is make this Christmas a safe one. Dont let the police knock on the door of your familyand friends. Below are photos of the accident, a gruesome reminder to drive safe.

Perth?

So Perth is fast becoming the most expensive place in the world to live, yet like Fremantle the whole state seems stuck in the dark ages. So I wanted to have a little whinge Perth Town Planning.

For the past year I have been staying in a cramped appartment in the kings park area. There are large numbers off appartments in the area, and heaps of commercial properties as well. However retail? There isn't any within 5minutes walk. And on a Saturday or Sunday there isnt any at all, you have to go into the city.

The problem I know, is multi faceted, however I have multiple suggestions to help.
1)I would like to suggest that all new multistory complexes should reserve an area for retail, a coffee shop, lunch bar, iga whatever. By forcing all new buildings to reserve this space should keep the price of rent cheap.

2)Now this might bring more people to the area so I would then like to suggest that complexes should take responsibility for parking. Rather then having just the street parking they should put some parking underneath for the public to stop by. A couple of bays at 1-2 hours should be fine, this would allow people to drive to the area without having to fret about parking.

3)Lastly take this and move it to all the inner city suburbs. My 700m² block has a 8 story 14 appartment building on it with underground parking. I dont see why these couldn't be littered throughout Leederville, Northbridge and so on... with their own parking and retail it would certainly make the place a lot more fun to live.

Guide to DeWalt

Ok if your looking at battery powered, power tools then DeWalt is definately one of the top brands. However they are a little naughty in that they dont publicly specify their batteries by amp hour ratings. This is important when picking a battery because it basically tells you the capacity of the battery. A 3AH is about the biggest you can get, 1.5 is the lightweight, and anything below that is pretty crap. So below are the amp hour ratings for all the current DeWalt batteries.

DEWALT Battery	Amp Hours
DC9181	1.1
DW9046, DW9048, DW9050, DW9051, DC9098	1.2
DW9057, DW9062, DW9072, DW9074, DW9094, DW9098, DCB120	1.3
DC9094, DC9099, DW9061, DW9071, DW9091, DW9095, DW9099, DW0240	1.7
DW0242	2.0
DC9071, DC9091, DC9096, DC9180, DC9360,DW9096,DC9280,DC9180,DC9144	2.4

This information is also available on the DeWalt support website.

VFD/VSD/VVVF Electrical eHow

I wonder if anyone will ever read my posts?
Well I am always asking Adrian to explain some Genetic thing or another so here is a little explanation on something that is in every persons house.

Ok in Australian Mining we call it a VSD (Variable Speed Drive), But its also called a VFD(Variable Frequency Drive) and a VVVF (Variable Voltage Variable Frequency) but what is it?
You probably know it as an Inverter. But what is it?

Well you all know AC and DC right? We all learned that at high school.
Step 2. You all know what a transformer does right?
AC power creates a changing magnetic field, you wrap a wire around a metal toroid and you induce a magnetic field in that toroid, then you wrap another coil around the other side and the magnetic field induces a current in the coil. This effect is called mutual induction.
P=VI ( Power = Voltage x Current)
If you keep power the same on both sides of the transformer you can reduce the voltage and increase the current and vice verse. This simple device is what won Tesla the battle for AC power generation over DC because he could easily step up the Voltage to reduce the current and deliver power with lower losses to his customers.  In DC there are no simple transformers because there is no changing flux.

So recapping, AC is cool, Transformers are cool. Right?
Nearly. According to this industry uses 40% of world energy and upwards of 60% of all of industries power consumption is through induction motors.

Now, the big problem with AC is that all of the motors run at a fixed speed.
Your natural instinct would be to say why dont you just reduce the voltage? Surely that would slow the motor down?
Well unfortunately a motor gets its power through that previously mentioned mutual induction principle. So if you reduce the voltage the current goes up. In fact you can damage a motor but giving it too low a current by forcing it to draw more current then its wires can handle.

So how do you adjust the speed of a motor? Well first we can calculate the speed of a motor using the magical formula below
RPM = 120 x Frequency/Poles
In Australia, the Utilities deliver power at 50Hz and nearly all 3phase motors are 4 pole.
So, RPM = 1500.

Thats from that formula its pretty obvious if you want to adjust the RPM you just lower the frequency.

There is no transformer for adjusting frequency, but modern power electronics can. They first convert the power from AC into DC, then chop that DC signal into an AC signal at whatever frequency the user wants.

From Wiki

By varying the frequency we directly Alter the RPM of the motor. So if you have an Air Conditioner? Fan? Electric Car?

So yeah thats the theory behind how you control the speed of a motor :)

Getting up to date with linked in

Its taken a while to get right but I'm pretty happy with my linked in profile right now. I know its not really important in the grand scheme of things but its important to get it started because I'm pretty sure that having a good linked in profile is going to be like having a good resume in a few years. Having it done already is going to be a big advantage for me down the track when I am applying for Project Manager Positions ;)

Well I guess a link is in order
http://www.linkedin.com/in/zucaro
Pretty cool that I was the first Zucaro to get on linked in and request a custom URL. Love it.

Today I spent the whole day in a Engineering Training course. Learning about something called Arc Flash. Its not a very well known subject matter in the grand scheme of things but hey, electricity is important. The fact that you can read this on a computer / mobile somewhere shows that you use electricity. Try going home and living without electricity for a few hours and its just bizzarro world. I actually cant even get into my appartment without power. There is an electric sliding door with swipe card security, then there is the lift. There are no access stairs, only fire escape... So yeah I couldnt even enter my own house without power, but thats me getting side tracked.

Arc Flash Analysis is basically the study of the amount of energy released during a fault. It arises from the fact that switchgear degrades over time and accidents can happen (like digging through a cable with a backhoe) and this causes an arcflash to occur. Now against your natural impulse, its not the high voltage you have to be worried about in this case. High voltage faults although dangerous, dont have the same about of current that you get in a low voltage fault (low voltage here being 415V)

For example on the high voltage 11kV switchboard the amount of current in the fault is about 10,000Amps. Now thats a lot, however on the low voltage side its over 50,000Amps.
That current is enough to vaporise copper.
http://www.youtube.com/watch?v=-iClXrd50Z8&feature=related

Vaporised copper is at least 2500 degrees Celcius, and it expands from its solid state in a volitile explosion. If you are caught next to such an explosion unprotected it will melt your clothes onto your skin and you will be lucky to escape with your life.

So yeah. Thats a little about what Electrical Engineers do.

Life Update...

So started my new job as a Senior Electrical Engineer.
That's right Senior!
Pretty cool. Heaps of work to do and its quite challenging. But hey that's why I took the job in the first place. I like to go to work knowing that I am going to learn something new, solve a problem for someone and add value to a project. When it comes to Engineering Design you are really a part of building something. When I was working in construction it just seems like the whole game can get bogged down in bureaucracy and everyone trying to get the political one up on their respective rivals.

OK what else? My girlfriend and I have been dating for a whopping 3 years! Damn life goes by fast.

Tim has done a really good job with the Dental website. Kinrossdental.com.au
Pretty impressed with his handiwork.

I am living in West Perth now in a nice apartment. Still have a room in my house but haven't been staying there now that I can stay here.

Riding the bicycle everyday to work. Its only 6ks and its over before I have warmed up. But I guess its a guaranteed 15mins of exercise each way every day. I have already found my 30.

I also can't believe that I bought this DiNovo Logitech keyboard over a year ago. So? Well I haven't changed the batteries once. I cant believe it. Does the damn thing charge every time i press a button?
Hey There's a Patent Idea. Keyboard that charges itself based on the Impact of pressing keys. I think having a generator in each key is a little stupid. Rather have the two stands on the top edge of the keyboard have little pressure generators and leave the bottom as normal. I'm sure with my keyboards current battery life having two of those little suckers would guarantee a lifetime of use...

Hmm then how will you get the damn thing to start working once its run flat? Well a couple of well calibrated love taps should start it up.

Any hoot, I think I might post some more technical revelations on here. If I find a particularly interesting engineering problem or something I think I have enough engineering buddies to make it worth a read.

Well cheers. Until Next time.