Electric Motors in low current Circuits

Induction Motor

Electric Motors, Trends over the last 50 Years

For those born after 2000 and electric motor is seen as just another product of technology, just like the cell phone.  Electric motors have been with us for the last 200 years, personal handheld phone (Motorola and Martin Cooper) about 50. There is a link of course, that being switching devices.

Universal Series Wound Electric Motor
Universal Series Wound Electric Motor

Although it is an accepted fact that inverters and variable frequency drives are with us to stay, older technology relied on some pretty innovative ideas to increase and/or lock an electric motor’s speed.

Continue reading “Electric Motors in low current Circuits”

Innovation in South Africa

This steam evaporator aboard HMS Belfast distilled up to six tons of fresh water per hour for the boiler and for drinking

Innovation in South Africa steps up a notch!

Much must be said about our not so dearly departed prez, J.G. Zuma. He may have reversed the good in this country under his tenureship but he also turned the citizens into a bunch of aspiring entrepreneurs, innovators and budding scientists.  In times of hardship innovation always comes out tops.

It was not that long ago that our country switched from the bankrupt supply commission, Eskom to solar panels, inverters, batteries, gensets and methane gas. Our neighbours became experts in renewable energy,  domestic wiring, preventing backfeeds and LED lighting.

Electric stoves went from power gobbling electric elements to gas burners, electric geysers became gas, heat pumps and solar. Continue reading “Innovation in South Africa”

Electronic Circuits for Beginners

Electronic Circuits for Beginners - Prototyping

What to look for when starting out – Electronic circuits for beginners

What is the attraction behind electronics?  This is a sore topic in many South African circles chiefly because the architects of education are failing the academia, the principals and the teachers.  This in turn fails the learners, our future. This article, “Electronic Circuits for beginners” was written for grade 8 learners and in subsequent articles will hopefully add some value and direction to your schooling.  Education does not stop when you leave the classroom.

Electronic Circuits for Beginners - IoT
Electronic Circuits for Beginners – IoT – the spares box

Anybody whom loves reading should get a copy of the book “Elon Musk – How the Billionaire CEO of SpaceX and Tesla is shaping our Future” by Ashlee Vance.  Musk has all the makings of not just a great scientist and entrepreneur but a great leader.  He is regarded somewhat as an opportunist. Ditto Bill Gates and the gone but never forgotten Steve Jobs.

Electronic circuits for beginners – making a career choice Continue reading “Electronic Circuits for Beginners”

The Maker Community – The CNC Machine

CNC Lathe

The CNC Machine – a positive influence on our lives

An interesting topic gathering momentum is that of the CNC machine or Computer Numerical Code machines, machines driven by computers and becoming increasing popular within the DIY Maker community.

Here we will look at the basic CNC machine and suppliers in South Africa.

The CNC Machine Forums

There are endless forums on the internet covering CNC and we’ll look at this as well.  We don’t seem to have a dedicated forum in South Africa so we’ll put this under a category on these pages. Continue reading “The Maker Community – The CNC Machine”

Soldering and Rework Stations and other Kit

Magnum Rework Station 3005

The best soldering iron and rework stations for the job?

Of course this is a commonly asked question and the reply will always be to get the best one can afford.  Most home users are now spending a lot more money on getting better quality soldering and rework stations to complete projects. Cheaper irons, the home store DIY project types are not designed for intricate electronic circuitry.

Weller WSD81
Weller WSD81

There is no thermal control, the stupid tips wear away after ten minutes of use and after an hour one can hardly pick the thing up because it is radiating more heat than Koeberg. So bottom line, get one for an emergency – it will only last a day.  Do not use it on CMOS or static sensitive devices, just for simple home wiring.

Weller, Antex and Magnum Continue reading “Soldering and Rework Stations and other Kit”

Maker Space – CNC and 3D Printing

Why 3D printing and CNC machines top the maker charts

Building your own guitar? Cutting a face-plate for your new amp?  Designing and manufacturing decals?

For those of you just starting out, welcome to the club!  The Maker fraternity in South Africa is believed to be very much alive and well in Cape Town and Johannesburg where believe it or not Cape Town is supposedly the capital.

Not even 5 years ago CNC machines were slowly becoming the rage, 3D printing only just starting to make an entry into the maker space. Although using similar parts standardisation was a key issue. Stratosys is just one such manufacturer which dominates the market, with their smaller brother Makerbot being possibly the defacto for small scale prototyping.  CNC milling and lathing has always been a favourite topic amongst DIY modelers and professional craftsman.  They have become more accurate and cheaper. Continue reading “Maker Space – CNC and 3D Printing”

VU Meters Vs Bargraph

Volume Units and Decibels

My first peek at a Nakamichi was in Japan.  Sparse in detail, no flashing lights, VU meters or fluorescent displays.  Just so damned gorgeous. OK, then you have the PA-7, industrial strength, industrial looks and what a beauty. But if you one needs to really capture beautiful looking amplifiers, then look no further than the McIntosh range. Black in finish, blue lit VU meters.

Mcintosh MC2300
Mcintosh MC2300 – wiki commons awgrasso

So what to do if you need that really cool look and have a budget of a few ZAR?  Unfortunately VU meters, really good VU meters are not cheap. The question about where to source comes up often on the web and besides eBay where you may not necessarily get exactly what you are looking for, Meter Sales or Instrument Meter Specialties in the USA may be your answer. In South Africa the Model 543 is going to land at about R1 800.00 ex duties and VAT.  So make sure your amplifier is worth it.

The bargraph, long being favourite for many enthusiasts is your economical solution in most cases.  Why have a VU anyway if a bargraph is a better solution in many ways?  It all comes down to vintage. In the 50s, 60s, 70s and 80s most equipment was still analogue where the outputs were designed to be fed into an analogue recording device.  Analogue recorders are a lot more resilient to input overloads, in some cases even done deliberately. Not so with digital devices where the results are painful to listen to.  VU meters are very slow and don’t necessarily slot in well high with speed transients but they are brilliant for monitoring the average output amplitude.

VU meters with peak overload, monitoring the 0VU perimeter and making sure the VU meter is correctly calibrated is all part of your sound engineering experience. Continue reading “VU Meters Vs Bargraph”

Micro and Mini sound systems versus Dock

Logitech Bluetooth Receiver

The iPod Dock and Other Things

One of our readers,  13 year old Craig wants to know why we don’t do reviews, especially on docking stations.  Unfortunately as we don’t retail products and neither get support from resellers or manufacturers in this beautiful land of ours this can be pretty difficult unless we go out and buy the stuff ourselves.

Castle Knight 1
Castle Knight 1

What I can tell you is that over the years a common problem picked up is dirty or broken contacts in the dock which although replaceable does make it a weak link in the interface.  Line inputs are a better way to go but now that from Bluetooth 2.0 and up, wireless seems to be the cheaper and more practical way to go.   Docking stations are still popular but the home user wants more exciting permutations. Continue reading “Micro and Mini sound systems versus Dock”

Class G and H Audio Amplification – Gimmick or Wizardry

Texas Instruments TAS 2559

Class G and H Audio Amplifiers

One design that has been out for eons and still catches us off guard is the rail shifting Class G or class H boost supply amplifier.  Most purists agree that this concept is ideal for PA work but not high fidelity audio.  To a certain degree I must agree but then this would imply that class D is also in the same boat. There I disagree, they are in the same boat but some very high quality amplifiers are class G, H as well as class D. What is this class stuff anyway? Continue reading “Class G and H Audio Amplification – Gimmick or Wizardry”