Idols – Round number three

Well guys, round number two pretty much blew me away – I realised then just how great Jamie Lee (the one that got away fame) is or at least was for the show (which includes Gareth’s leer) and her few personal appearances were actually, I felt compelling viewing. (esp. in her bikini).  Talented she is but sadly, she never made the vote. She sang “Save Me” an old Clout number – although it was extremely popular years back, so popular that I recall seeing it on a jukebox in Houston, the song was played to death and I fear the song did not save our Jamie Lee. Well done Jamie Lee, now go on and show us your talent outside the confines of Idols. Yourself,  Bongi (may the stars always be with you my son) and Gail (the gorgeous one). Putting lecherous thoughts aside let us continue…  Continue reading “Idols – Round number three”

Inductance Heating – Switching Circuits

Inductance Heater - parallel LC

Inductance Heating – high frequency switching


As with most circuits published on the web it is advisable to make sure that you analyse and understand them before putting solder to component. It is interesting to note that a lot of the circuitry used in these designs is not unique, there is no patent and therefore should not be a hindrance if one were to steal the design and enhance any weaknesses  – however because you are working with high voltages, high energy and circuity designed to generate heat you can burn down your workshop and/or electrocute yourself. Don’t attempt these circuits if you are not comfortable with high voltage circuits or have only built a 9V astable multivibrator.  Sie wurden gewarnt!

Inductance heating is not new – industry found a way to use this concept in foundaries many decades ago. In actual fact if one had to build a mains transformer without laminatiing the core to limit eddy currents you will quickly discover the concept. Where to from here?  Well, one of the beauties of modern electronics is that component pricing has not increased like your basic foodstuff or clothing or beer. Electronic components have become more reliable and cheaper. So basing your purchases, dollar for dollar you can’t go wrong with electronics as a hobby. It is not unheard of to hear engineering students starting their own business from home: knowledge x creativity = wealth. Inductance heating nowadays use very fast switching circuits running at over 200kHz. This equals smaller components equals lower costs. A 300W power supply costs under 20U$ to build. (in Asia, that is). Home brewed inductance heaters can cost as little as 100U$ for a 1kW unit. (Update:  A pre-purchased unit in the 3rd quarter of 2013 cost under 50 U$D for a 2kW heater).

The most expensive single component on mine was the copper tubing (to heat bolts and nuts to white hot).. Your inductance heater consists of 5 main blocks – the frequency generator, the gate driver, the switchers, a DC blocking capacitor (I put this in a separate block because there are safety concerns without this, like frying yourself instead of the work object) and of course, the most important block of all the tank circuit. For those budding electronic engineers it is advisable to learn up on tank circuits from our friend Wiki – I was fortunate enough to go to radio school in 1980 and resonant tank circuits were covered ad nauseam. Yes, the good old Conqueror transmitter and Apollo receivers (Marconi).  The LC networks used in the inductance heaters of most of our linked circuits all had one common problem – damage to the capacitors due to the very (read:  very, very) high currents through them at resonance.  Careful planning and layout with air and water cooling in the tank circuit is one workaround. Oil filled capacitors are very expensive but in theory a better alternative.

The People

From my own research four engineers have contributed more than most to the field of inductive heating on the web and they are Tim Williams, John De Armond (Neon John), Jonathan Kraidin and Richie Burnett. If readers of this article know of anyone else’s work I’d be only too happy to submit a link here as well to their website. 

The Tank Circuit

Typical Tank circuit block showing parallel LC network (also see Richie Burnett’s website on induction heating). The coil surrounding the white hot bolt is known as the work coil. In an efficient circuit such as this the bolt will become red hot within a matter of seconds. Richie’s website covers the theoretical aspects used in parallel and series resonant circuits. Maybe it may be a good idea to look up resonant tank circuits on the web as well. Radio transmission (or receivers, mind) has always intrigued me and of course what is radio transmission without LC tuning tanks.

 Below: A simple block of a typical inductive heater


Inductance Heating - parallel LC
Block diagram of inductance heater – parallel LC Tank
Inductance Heating - work coil and M8 bolt
M8 bolt – white hot – Richie Burnett (go Richie Burnett’s Tesla Coil web pages)

Tim Williams

I found Tim’s experimentation and interesting articles a definite must read.  Although all the links here are excellent I found Tim and John Neon’s a load of fun to read and for anyone whom has a definite interest to build his own heater Tim does cover all the “nasties” associated with the tank and switching circuitry. Tim has split his explanations, experience and working model over nine pages. Do read them all starting with page one. Tim’s schematics on page six are copyright so be warned.

Below is a picture of Tim’s 10kW induction heater which he also manufactures and sells. The tank “capacitor” can be seen beneath the meter. The half bridge switchers are four FGH80N60DTU IGBTs, water cooled – powered by a near 2000ufd 400V smoothing circuit.

Inductance Heating - Tim Williams
10kW Inductance Heater – Tim Williams (very gifted and of course a fascinating website)

John De Armond

John’s disclaimer is the funniest I have read in a long while. John supplies schematics and tons of information. Neon John as he is known professes to be a baby boomer like this parts-ring scribe but obviously has many talents that most youngsters of today only dream of. It’s good to see wit and ingenuity thrown in. BTW he links to his friend Jonathan Kraidin whom supplies stunning information on his own project. Very well written, clever, informative – a must read. Here something else can be learnt – PLL or phase locked loop circuitry. Many of the circuits available on the web are switched from an inverter driven by an oscillator set to the resonant frequency – this one changes the frequency to lock into the new inductance and hence resonance frequency (combined work coil which inductance changes according to temperature and work piece inductance).  Johnathan’s schematic can be found here. The entire series can be read from here.

Inductance Heating:  Some more information:

If you are a newcomer to electronics there are some things which one must know in order to understand the inductive heating process:

  • Power supplies, full and half wave rectification.
  • Power supplies and voltage regulation. Symmetrical or split rail supplies.
  • The Curie Effect.  What happens to a magnet when it is heated?
  • What is an inductor?
  • What is a capacitor?
  • What is an LC circuit?
  • What is Power Factor Correction and Q?
  • Fast switching semiconductors: Mosfets and Bipolars.
  • Switched mode power supplies.

Yes, there is plenty more and the order of importance is not important. As one moves through the basics you will find they all have their own little niche. Readers should find that Wiki will supply all the answers but unfortunately, such is the nature of electronics formulae can be offputting. Stick to the basics and then once fully understood move onto the more intricate part – formulae and some maths. Years ago I was overwhelmed by the amount of maths involved in simple radio antenna – nearly put me off radio for good. Unfortunately it’s all part of the learning and understanding aspect of any technical subject, be it human blood to cutting down trees.  

[Ed – some of these images may be copyright infringed – for any concerns or ceases please contact our webmaster @ this]

Whilst inductance heating is certainly not a new ‘discovery’, one can only be inspired by the marvellous work of Richie Burnett, Tim Williams and John de Armond.



SA Idols – before round number two

Sundays are great days for doing research and if one had to excuse the ‘connection’ between a parts website to a musical concert I have been fascinated by what feedback previous idols shows have received. Blogs are full of  such negative publicity towards Sasha Lee (South African Idols co-winner season five) that it makes one wonder what the public are actually looking at?  Continue reading “SA Idols – before round number two”

Asian Motorcycle Engines

Are their fuel injection systems for older naturally aspirated engines? There seems to be huge amount of suppliers on the web but the intention is for manufacturers to have their wares consolidated on these pages. In South Africa where this website is hosted we have Master-Parts and Midas, two of the larger companies supplying after market parts for motor vehicles. What about motor cycles?  What happens to scrapped motorcycles? Are these scrapped because their natural life has now been exceeded?  Motorcycles are notorious for having a short life span yet many of the cheaper Chinese motorcycles seem to be using older Honda engine components so would it not be cheaper to use a new engine instead of rebuilding a worn out motor. Are the Chinese thinking of bringing out a four cylcinder motor sometime?  I found this website of considerable interest: – now how does one go about ordering only one engine if you are not an importer/distributor? In South Africa there is a cloud of mystism around the demise of Vuka distribution – read here. It’s encouraging to see someone like Frans Earle taking ownership of a problem which wasn’t his in the first place, to keep this very popular brand alive.

I read with interest about motorcyclists in general complaining about the Chinese motorcycles. Yes, they can be cheap and nasty. The question is, were these bikes built here or in China? Do we have qualified mechanics working on these machines? A very large problem we have in South Africa is the forced integration of non-skilled workers into all fields of business. The build of CKD/SKU motorcycles are going to be just one such industry. I do not envy the owners of companies bullied into taking on people that have no passion for their job, especially one in which loss of life can be a result. As the New Consumer Protection Act draws closer this is only making matters worse. But having ridden motorcycles through the most part of my life the onus is always on the rider to take responsibility – motor cycles are NOT toys and should always be treated as if something WILL go wrong. If you don’t have an affinity for mechanical things find a responsible and passionate mechanic. I knew just such a guy years back whom immigrated to the UK unfortunately. He gave me the names of the best mechanics in cape Town and believe me there weren’t many.  I don’t mean this to be derogative, in actual fact one company that has an outstanding record is Suzuki South. (Cape Town).

Getting back on track, if I had the money I would be right behind the motorcycle industry for starters. And my prime interest would be around the supply of engines to people that already have the rolling stock or want to build their own, whether it’s for carts, motorcycles or any other project requiring motorised propulsion. Another industry is the supply of electric motors and alternators. How good are the Chinese electric motors currently on the market? If they aren’t good now they certainly will be in the future. My own experience with the Chinese motorcycle engines isvery limited but from what I have seen they appear to be reliable with only one complaint from a colleague in that the jet needle (throttle needle) came loose on his Vuka. But that used to happen on the Jap bikes as well! So it appears that they are reliable and maybe if the owner riders did a bit of homework and saw to it that parts were not working loose there wouldn’t be any incidents. Did anyone tell these guys that motorcycles are notorious for having parts drop off. In one case, a freidn of mine had his drive sprocket fall off the wheel hub. Now that came down to a very poor service indeed by the agents. Where were the locking tabs?  Again, don’t hop on a mtorcycle without checking for this kind of thing. I had an old Suzuki (GS550M) where the primary drive sprocket used to work loose. And it was lock tabbed. I put it down to excessive engine wear and poor carb sync causing excessive vibration. Suzuki state that they never had it happen on their bikes – well this one had done near 100 000Km. Now if only China could supply me with a suitable engine replacement.  I wonder just how much a complete top-end rework costs these days on a 4 cylinder 600cc?  

Motorcycle Parts

One of the very big reasons why the authors at Parts-Ring decided on this website is the lack of availability of second hand parts for older bikes. A dealer in Cape Town was overheard saying “if you don’t like the price get a newer bike”. Has anyone seen the price of parts in the South African market compared to the USA and wondered why we tolerate it? In all honesty – Gauteng (that’s our upper region – Johannesburg) seems to be more in line with biker’s needs than down in the Cape – we don’t have many businesses dealing in scrap but I doubt that everyone is out there buying a new bike.  If anyone feels differently please drop us a line – I’ll be glad to set it right.

One business that is very much on the rise in South Africa is the sales of motorbikes – this term encompasses anything on two wheels in our case. Scooters are now in abundance, thanks to the Chinese exporters – they make good machines although we get complaints about the quality. Hang on, who wants to do 100 000Km on a 100cc anyway. Most small bike riders are still learning the basics and will discover in due course that a bike can only be driven for a short distance before a little bit of maintenance needs to be carried out. Like any vehicle – except bikes are a bit more prone to wear and tear. “Do the maintenance newbie riders – your life depends on it”. Continue reading “Motorcycle Parts”

Courage under Fire…

South African rugby hit an all time low yesterday with the Springboks conceding a last minute penalty to the Wallabies. No excuses here this time round, the Boks started late as they did last week, sort of got their game together and blew the Wallabies away in the second half until losing to a 55m penalty kick. The Wallabies proved on the day that they were better.  I read the papers daily. I read the blogs daily. Everyone is pointing fingers at John Smit and Peter de Villiers, our champion of champion quotation kings.  The question that arises is whether the Boks are ready for the world cup next year. Are they? Continue reading “Courage under Fire…”

Idols Jukebox – select your winner here.

Tonight South African Idols brings you a pretty neat roundup of music. No doubt selected for our top ten’s particular style it’s going to be an interesting ride. Jess and lloyd are going to rock tonight. They should all rock though.  It’s the first time ever that I can honestly say I’d buy any of these guys albums if they were available right now.  I’ve never been able to single out more than three wannabes in any line up of ten – this time it’s the entire clan. Something that I picked up were the words of wisdom from our show’s judges and this relates to the singer needing to understand the song.  With a line up of many professional musicians I think this is one of the reasons that we have such a pool of talent currently.  Adeline has the beauty to have the judges gawking  but has she got what it takes as the stakes get higher? The dark horse here either seems to be playing a tactical game or is very good with song choices. Tonight is no different. Continue reading “Idols Jukebox – select your winner here.”

False Prophets and Idols….

Oh my gosh, my golly, golly gosh! Another freaking political storm and corruption plot to wake up to in the Sunday Times this morning. (The SAPS Office Block Plot). When will it ever end? As South Africa watches the DA and the ID join forces and the ANC promise that they will take over the Western Cape next elections I’m starting to wonder as to what is happening in the political arena, this spectacular never ending circus and even more magnificent run of side shows. Continue reading “False Prophets and Idols….”