@@@F_Titel P.O. BOX 1414 @@@F_Text @@@Bild 52.TIF @@@F_Textfett Handing on to the very young @@@F_Text Dear Editor: I am concerned about the shortage of young engineers in this technological age. During the 1920s, many became interested through building wireless sets. When I was a student during the 1950s, there was a pioneering interest in home-built television and tape recorders. But looking though current kit catalogues I find few projects which are simple and attractive enough to interest children under, say, 10 years of age. The following describes an approach to overcoming these problems. I believe that you must have a number of readers who are parents and would find it of interest. Having met with some success in introducing technology to my three grandsons, I would like to explain our practical activities over the past few years so that others may benefit. My experience is with boys aged up to 7 -- I see no practical reason why girls should not benefit too. It all became because of the following. 1. My daughter and son-in-law needed back-up in keeping three lively youngsters occupied, particularly during the school holidays. They were therefore keen for any help to be a success. 2. Such young boys have such a keen appetite for new experiences that it seemed a pity not to channel this drive into a useful direction. 3. I was aware of the fact that society needs a more plentiful supply of keen, practical engineers for the future. Early efforts to involve the eldest child presented few problems. I found that up to the age of about 5, play takes the simple form of a desire to 'bash things up'. I have a small workshop in the house, and an ample supply of old printed circuit boards that would respond to the old wire cutters or hammer. We have a convention that grandpa keeps any valuable salvaged components. For safety, it is necessary to accompany the child continuously, pointing out how to avoid injuring the hands or eyes. No child wants to be hurt, but the enthusiasm is likely to get the better of him at times. Up to the age of 6, I allowed him to use wire cutters, pliers without the shearing cutters used on electrician's pliers, light hammer, wire strippers, and screwdrivers. It is problem when the second child arrives on the scene, wanting to join in. After some worrying sessions with two or three, I had to conclude that it is only possible to supervise one child a a time. That way, it has been possible to limit injury to minor scratches needing nothing more than an adhesive plaster to clear away the tears. When he was 6, I began to step up the inducement to start a constructive project. Note here that broadcasters and school staff are obsessed with the word 'science'. This implies theoretical principles rather than functional hardware, and is a passport to a child's apathy. What I sought was a battery-driven device (for safety) which was rather unusual, but would play a part in the children's play when complete. The solution came from the eldest child. He wanted a traffic signal. The specification soon fell together, with the help of the Maplin catalogue. It is very important to prepare each session before the child arrives. @@@F_Text @@@F_Textfett Specification for chosen project @@@F_Text PP3 BATTERY. 4 sets of red, amber and green LEDs, large, one of the sets in each of the four faces of a single signal head. 4-position rotary switch which, turned clockwise, is hard-wired via diodes to give the correct signal-light sequence for a pair of intersecting roads. Battery switch. Signal head made from pieces of oak. Post of brass tube, supported on an aluminium box for controls and stability. It is as well to buy some 20% spare components. They tend to get lost or damaged. Total height 24 cm. Construction is proceeding apace, the mechanical part being completed first. It is practical to use most hand tools, guiding his hand with saws and files. When the electrical construction follows, it teaches him a good deal if much testing is done. It is stimulating as he likes to see the facilities springing to life. At this early stage there is no need for Ohm's law and other theory, but I have shown or told him the following. 1. What happens if too much current is passed through a wire. This was done by shorting an old car battery with a piece of mains cable, with child standing well back. 2. How some components have to be connected the right way round, while others do not matter. The clearest example is an LED. 3. How too much current will run a battery down fast, for instance, with a short circuit. An analogue voltmeter is best, although the units and numbers do not yet mean much to him. 4.How getting involved with the mains can lead to severe shock or even death. Death stories appeal to the very young. 5. How other metal parts as well as wires can conduct current. Bear in mind that the whole involvement is a kind of practical play, and it is wise to get junior to do as many of the processes as possible. This makes him feel keenly involved. We now come to soldering. I first showed him how the iron quickly reached the temperature where it would boil water (spit), and how it continued to heat up until it would melt metal (solder). I then went on to state how parts of the iron became hot enough to cause burning, insisting that I and only I should handle the iron. Danger appeals and concentrates the junior's attention. I repeated the description of the dangers as they occurred, of remaining with the iron for all the time while it was hot. It is important to demonstrate that soldered items take time to cool down. The actual soldering is done thus: I hold the parts in contact and apply the iron, while junior applies the solder. This works well, as he provides the oft wanted 'third hand'. Using the methods described above, it should be possible to construct a device that is reliable. Do not worry too much about the finished appearance. It is an achievement to complete the project at all. Glues like white wood glue, clear Bostik and Plastic Padding have great appeal, and paint is no exception; but be ready with plenty of clean rags and solvent. Remember that mothers are particular about paint on clothes, and that solvents may well cause temporary damage to junior skin unless it is washed off immediately afterwards. The time span of interest for the very young varies from child, but be ready for him to start playing at almost any stage. He will probably come back in a while. When the project hardware has been completed and tested, it must be given to junior to keep. This is a powerful inducement to complete it. I have no doubt that there can exist a vast difference between the psychology of one child and the next. This letters should therefore be taken as general guidance only. Nevertheless, I wish you well in initiating new, keen and practical engineers. An early start can be the best basis for a lifetime interest. J.M. Bentley, Loughborough @@@F_Text Congratulations on your marvellous endeavours! Efforts like yours will hopefully do much to restore the strength of (electronics) engineering in our country. Comments from other parent readers are welcome. [Ed.] @@@F_Textfett PIONEER OF COMPUTING @@@F_Text @@@F_Einleitung Dear Editor, as an amateur who occasionally dabbles in electronics, I have recently become intrigued by some of the early pioneers of computing. Especially interesting is the work of Conrad Zuse who built a calculating machine constructed from several thousand electromagnetic telecommunications relays in Germany around 1934. I believe a working example still exists in a museum there and fills a whole room. I am attracted to the possibility of building a device along these lines as logical thought and patience are the main requirements, the individual components being straightforward. There is also the satisfaction of making such a device function without the use of a single semiconductor. Circuit diagram for such a machine are a little hard to come by! My own design for a modest device capable of performing additions of two, eight digit, decimal numbers and multiplication by serial addition, requires about 200 relays. Whilst it should work, I wonder if anyone else has experimented in this way for their own amusement in recent times, and if they would be prepared to correspond with me. It may be that my design can be made more efficient before I begin the rather laborious task of construction. John Dingly, Swansea. @@@F_Text Anyone interested in this undertaking, please get in touch with the Editor.
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