Smashing the third-rail myth – or not?!

I am sure that most of the parts-ring readers have seen or read about mythbusters, the zany American TV series designed to dazzle you with the brilliance of Adam Savage, Jamie Hyneman and the rest of the crew set out to explore the truths and myths behind urban legend. Oh yes, most of it comes out true in the end but what about pee’ing on the third rail. I doubt very much that commuters in South Africa or the UK for instance would take a chance of pee’ing from carriage to power line but then again stranger things have happened. Here Mythbusters examine the pee’ing on the third rail legend.

Runaway Jet Engine

Being an avid lover of jet engines and the Darwin Awards I just had to post this snippet on these pages. Four things spring to mind:

  1. The operator has no ear-muffs;
  2. the jet engine is tethered to a pallet;
  3. it’s leaking fuel like a sieve.
  4. They must be Dutch.

2800W audio amplifier – link

Interesting website for various audio circuits can be found here.  ( Trying to load the link under the technical library came up with a spam error so we are posting the information here – the amplifier is significant in that is of a very simple design. When high powered amplifiers are of simple design it doesn’t mean that we can take chances – chances are that you’ll rupture the  output devices before the fuses like all electronic circuits. There is no current limiting fed off the emitter resistors of the power devices so if you play into a short circuit your lights are going to go out. Yours and the amplifier. This amplifier uses technology which is not new – it also uses transistors which in NO way will manage to handle currents at 1400W.  A word of caution: These transistors are 200W devices with a max Ic of 16A, so if you are typically sitting with a +70V -70V symmetrical power supply your max current into the 4 Ohm speaker is going to be in the vicinity of 18A which is over 1000W dissipation using I * I * R. Therefore if you are planning on pushing out this kind of power do add more output devices in parallel – this means more drain on the driver circuitry plus, plus, plus. So do the maths and be cautious. If you need a design where caution, good layout and engineering skills have been used then I’d suggest going to Elliott Sound Products, possibly the best website for tutorials, information and solid engineering advice.  There is nothing better than a simple design – just know the pitfalls. High powered audio comes at a price and this will always be around expensive mains transformers and loudspeaker drivers. If there is no protection you will burn a voice coil. If you overdrive a loudspeaker and you get the slightest hint of distortion be rest assured that the voice coil is starting to overheat. If one transistor in the output stage blows and you have no way of checking symmetry on the output the DC offset will damage the speaker before the fuse blows. Not wanting to sound like the Grim Reaper, do your reading and understand the dynamics of Ohm’s Law.

The 2800W audio amplifier is one of two mono block 1400W audio devices so it’s essentially NOT a 2800W amplifier but two 1400W amplifiers. Specs for the output devices can be found under the technical library – the component breakdown is as below.

T2_____2N5551 / C2240
T3_____2N5551 / C2240
T4_____2N5551 / C2240
T5_____2N5551 / C2240
T6_____2N5401 / BF423
T7_____2N5401 / BF423
T8_____2N5401 / BF423
T9_____2N5401 / BF423
T18____2SC2922 / MJ15024G
T19____2SC2922 / MJ15024G
T20____2SA1216 / MJ15025G
T21____2SA1216 / MJ15025G

Muscle cars – GT500

If you are an enthusiast of muscle cars then I’m sure you’ll appreciate the youtube link to the video below. I found it laughable how the hacks on the site all had a complaint how the horsepower was measured. Don’t despair kind sirs, the Brits are fairly conservative and I would not doubt for one second they measured the power with a dyno…. I gave up trying to work out the potential power through physics – a straight dyno test does it for me. Maybe for you too….


Apologies for many of the links not working or the images not displaying – it was a task passed on to one of the may importing plugins offered online from Joomla to WP but it obviously likes part of the text and not all of the images. In time we’ll add the images back but insofar as the inductance heater goes, well – keep primed, the links are great and they all work. 1M kudos to the scientists come entrants.

What is Dark Fiber?

Embarrasingly enough I heard this term not so long ago and didn’t have a clue as to what the person was talking about.The good news is that it’s nothing new – a well laid out network will utilise extra network cabling or lines which although unused saves the considerable expense of having a civil engineering company from having to re-lay cabling when the need arises . Of course in the event of a failure of one or more lines there is now also a redundancy check in place. These unlit or ‘dark strands’ of unused fibre can be leased out to companies requiring optical connections. Interestingly, the term ‘dark’ is still used if lit by the lessee and not by the owner. Continue reading “What is Dark Fiber?”

The OPiC System - Online Parts InternationalThe OPiC System – Online Parts International

Trying to avoid the repetitive nature of any website is not an easy task – the idea behind this parts-ring website is to maintain a portal for all and sundry to advertise the purchasing, selling or exchange of spares used in any industry, from model cars to agriculture. An issue which often arises is the need to keep advertisers under one blanket – not to go ape or have millions of links all over the place to confuse readers but to have a properly laid out portal, easy to read and navigate. Yes, it is blog style and no it isn’t just a blog. Continue reading “”

New Energy Resources

One of the cheapest forms of energy comes from a very old process:  nuclear fission.  Fundamentally fusion is the better choice for generating heat to drive the steam turbines but is technologically very advanced and therefore more expensive but has very little wastage. To pack all nuclear reactors into moth balls and move on to safer forms of creating electricity is not going to happen overnight.  But what are the alternatives? Continue reading “New Energy Resources”