eJournal for teachers of electronics and communication technology
It is difficult to achieve timing delays of more than a few minutes with the standard 555 circuit because of the way electrolytic capacitors behave. When the capacitor plates are charged a small current passes through the dielectric – this is called the leakage current. A real capacitor behaves like a perfect capacitor in parallel with a leakage resistance. To […]
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The When I reached secondary school at the age of 11, the very first project I made in Technology (woodwork as it was then called) was a table lamp based on a halving joint. When I arrived at my present place of work, I was amazed to find that similar projects were still being made! Fortunately such projects have since […]
Continue reading »The NE555 timer first appeared in 1971. Although it is now nearly 40 years old, many exam boards still include it in their specifications. This seems rather odd in a fast developing subject such as electronics. With an ever expanding range of new technology and devices to learn about, perhaps it is now time to relegate the 555 to the […]
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