Prompted by an article in the Popular Mechanics Magazine, “Vintage Audio in the Digital Age” by Mark Wilson – December 2011 I thought it pertinent to add a few cents worth. There is a lot of truth in the sentiment that valve audio sounds better than modern semiconductor audio – this I have heard from a lot of audiophiles over the last few years and compounded by the fact that I have actually done a comparison there is something to be said for this. However, in this lies also a problem – cost versus satisfaction.
(b) 1845 – (d) 1923
In 1895 Röntgen generated electromagnetic radiation in a wavelength range called X-rays; he received the first Nobel Prize in Physics in 1901. Röntgen’s scientific papers were destroyed on his death in 1923 as requested in his will. No known patents were filed.
We all think we know whom Albert Einstein was, most think of him as an inventor. He wasn’t, Albert Einstein was a German theoretical physicist better known for his work on general relativity. How about Walter Hunt, George de Mestral, Spencer Silver, Art Fry, Martin Heinrich Klaproth and a personal favourite Wilhelm Röntgen? Feel like adding your own bit of trivia? Go HERE.
Who found what is Parts-Ring’s educational posting – add your 10c worth, we are all interested in great discoveries, inventions, patents and of course ridiculous and absurd things to be seen in every day life. Go to the answers, replies and comments pages here
I read with interest on the web various stories of expensive repairs to cars – what to avoid, where to avoid and of course what to do. A very important fact of course is always which car do you drive or which car are you planning to drive? Any car which is designed for speed and comfort, think Mercedes, Audi and BMW will not be cheap to have any major services done, don’t even think about catostrophic engine failure. Of course then must look at the maintenance crew – some garages just charge more, they have higher overheads and good mechanics are not cheap. I owned a Ford 1600cc many years back – it was the luxury version of the XR3, 4 door and had all the trimmings. Expensive to run? No. Cheap to service? Yes. Replacing the cam belt cost cost 120 dollars (US). As a cheap runabout this was a fantastic car – but this car was sold off and I had to move into the real world. Modern cars have many electronic features that the driver is not even aware of. When you buy a new car these days these are not optional extras, they are safety features. Ask any Renault owner. Continue reading “Expensive Car Repairs”
Anyone whom thought that slapping a home brewed filter together to act as a loudpseaker crossover was a simple task should have his head read. Loudspeaker design is a science with very little fiction. Continue reading “Active Versus Passive Crossover Systems”
Just like food prices which seem to escalate every time the economy merchants bark, we see auto companies supplying parts turning to their calculators and pushing the PLUS button. I’m looking at statistics and Audi dealers seem to be pretty efficient at this. I hear Nissan and Renault drivers complaining about parts prices as well. In fact it’s the entire industry. Will we all eventually drop to our knees in unison and pray for a magic carpet which could take us to work every morning and hopefully back again safely if it doesn’t have a breakdown. Or rather why not start becoming just that little more proactive and buy from manufacturers that don’t hike their prices because they need to make a quick buck. Students of motor vehicle technology will be quick to tell you about the best part to use, dealer motor mechanics will warn you about the pitfalls of using generic parts, backyard mechanics will warn you about buying dealer parts and while this may stun and numb the cerebrum cortex, sanity does prevail. Once again the Chinese are coming to our rescue. But first of all let me tell you about the sorry tale of the ‘wannabe mechanic who reverse polarised his vehicle’.
In order not to confuse we will stick to three types of UPS and the electric motor-alternator or frequency converter, which is; the standard inverter or standby UPS, three phase motor generator unit (better known as rotary frequency/converters), the line-interactive UPS and the double-conversion / On Line UPS types. The inverter in its simplest form was known as an inverter / charger as it would charge the battery when power was good and switchover to inverter status when power was down. It consisted of a multivibrator circuit running at upwards of 50Hz (square-wave), a buffer circuit which in junction with the multivibrator would drive power bipolars or FETs coupled to a transformer which was in most cases a laminated type. A relay acted as the switchover. It was a simple abut in it’s simplicity came it’s biggest drawback – the time taken to switchover when mains power dropped would cause the load to lose power momentarily, not nearly good enough for electronic equipment, especially computers or data retrieval systems. They were then used more often than not as a simple means of backup power often in caravans and for camping.
Recently I was posed with a training dilemma facing sales staff at a national distributor of computer hardware as to why UPS sales were so poor. UPS pricing margins are relatively high compared to fast moving peripherals and components and is therefore more immune to forex fluctuations and should be always on the priority list of sales staff – the question raised then is why they move slowly until there is a catastrophe on the grid. A lot of the forums written about UPS are tainted by ignorance which is a pity considering that they play a very important role in protecting your computer or other sensitive electronic equipment. I have been involved in the design and repair of UPS equipment for almost three decades so hopefully this article will debunk a lot of the theories out there.