Author: Cathleen Shamieh
Reviewer: Harry Fairhead
A book that introduces electronics to kids - what could be a better preparation for the modern world?
Judging how good a kids book is, is no fun. Kids vary so much that what works for one falls flat on its face for another. Electronics is a very under-taught but important topic and so getting a small person interested in it is also important. It doesn't get much coverage in schools and as a hobby it just isn't as popular as it once was. Presumably it is too easy to get exciting gadgets without building anything. However, in the real world someone has to build it before you go out and buy it and hence a deep knowledge of electronics is a meal ticket for life - especially so if all the predictions of the growth of the IoT come true. The mix of being able to program and deal with electronics is probably going to be an even bigger meal ticket.
But wait, with all this talk about future earnings it is too easy to miss an important point - electronics is fun.
This book takes a fairly traditional approach to teaching electronics by way of a set of graded projects. It is divided into five parts and the first of them gets you started with some shopping. It goes over what and how you should buy to have some components. It laments the fact that you can now no longer buy components on the high street - a big indication that electronics is not he hobby it once was.
Most of the recommendations are sound, although it misses out on exactly what most books miss out on - how to identify capacitors. Resistor color codes are no problem, but when you are faced with a packet of mixed brown ceramic capacitors figuring our what they are is tough - and no help is given. Sadly one of the tools not included is a soldering iron because all of the projects either use a prototyping board or wrapped wires. Presumably recommending something that can burn is not a good idea in a book for kids - but I have some advice. Get a soldering iron and learn to solder - it is worth a burnt finger and if the subject has any dexterity at all they won't burn anything.
The first project is an LED flashlight - I thought everyone just used the flashlight app on their phones these days. Finding a first project is difficult and it has to be said this one is not inspiring, but it does the job. We meet an LED, battery and a current limiting resistor. The whole thing is made by twisting wires together and a rudimentary case is constructed using adhesive backed foam. As a project I don't think you could squeeze any more craft skills out of it.
A good point is that the book does not avoid circuit diagrams. Unfortunately they are all presented after a project is more or less over. Personally I prefer to see a circuit diagram before considering building anything because it sums up what has to be done and makes the steps seem logical. I would suggest skipping ahead to see the diagram before reading the steps - only one of the projects lacks a diagram.
Project 3 is about using a prototype board to construct a very similar LED circuit. It also investigates series and parallel connections using LEDs.
Part II is about projects that work with light. A traffic light, light timer, stage light dimmer and a smart night light. Of course all of these projects make use of just standard LEDs so they might not hack it in the real world. The light timer uses a big capacitor to demonstrate charging and discharging. The stage light dimmer introduces the transistor - a BJT. Most educators seem to think that using an FET is an easier option because the way a current controlled BJT works is more difficult. It is arguable, but by now the fact that the circuit diagram comes at the end of the project is becoming a real problem.
An equal problem is the use of a pair of complementary BJTs in the final project. The actual circuit is a big jump in complexity. The npn/pnp pair is used to create an non-inverting two stage amplifier but most electronics novices find reasoning about npn and pnp transistors tough. Most circuits for this sort of thing aimed at the beginner either use a single transistor or a pair of npn transistors with the LED in the emitter of the second - so providing a non-inverting amplifier without having to reason about npn and pnp BJTs. This is overly complex.
Part III introduces integrated circuits with everyone's favourite chip - the 555 timer. It is used to flash an LED and to drive a speaker with a transistor and light-dependent resistor. The final two projects are a light controlled sound generator and a one-octave keyboard. By now having the schematics at the end of each chapter is becoming silly.
The final part of the book presents Advanced projects. Of course, what you think is advanced is relative, but we do get to use some bigger integrated circuits. The first project is a roulette or guess the number wheel using a CMOS decade counter chip with a 555 timer as a pulse generator. The second is a three-way traffic light using the 555 and decade counter again pulse some diodes.
The final project is a radio using an LM386 chip for audio amplification. The amazing part of this project is that the variable capacitor and the coils are made from scratch. This is amazing as you could just as easily use off the shelf components. I have mixed feelings about this, remembering the trouble I had as a beginner with home made coils. However, this is an inspiring project - if a home brew radio is inspiring anymore. But the chapter closes the book on an even more irritating note - no schematic. How anyone is supposed to conceptualize the circuit is beyond me.
Overall this is a reasonable collection of projects for the complete beginner. The explanations are good but necessarily incomplete and sketchy. Whether this book is a success for a particular reader depends on the extent to which the projects are motivating - who can say?
By the standards of the gadgets, games and apps that the average kid is exposed to, my guess is that it is going to be a rare instance that is impressed by a pocket torch or even a home brew radio. This is not the author's fault, rather the state of the world. Perhaps a better introduction to electronics is via something bigger and more modern - an Arduino with prewritten software or something connected with a smart phone. The electronics has to be an add-on to a bigger system to have any real excitement for a modern youth.
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