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RCD Devices

As there seems to be a few mis-conceptions about RCD devices and PME, I thought the following diagram might help. In the event of a Neutral conductor failure, domestic load current from your property and and (possibly neighbour's) consisting of several 10's or 100's of amps will still return to the sub-station transformer via the Electricity Co.'s bonding Neutral-Earth at the distribution point. The earth connection obviously has some impedance, so the current flowing through it raises point A by V=I*R volts. So now our mains earth is floating at "V" volts above the general mass of the earth. In our shack this means our nice shiny radio chassis is at V volts above real earth. But outside we have an aerial with a ground connection, feeding into the shack, by, say, co-ax. The braid of this co-ax is at real earth potential which is currently below our mains earth. If I now undo this co-ax lead from the rig, I am holding in one hand "real" earth (co-ax), and in the other mains earth, which is higher, therefore current flows through me. It doesn't take much to see that this electrocution current has flowed through my RCD in both directions, so it is still balanced and has no reason to trip.

Ever wondered what is inside those tiny B&W or Color cameras that transmit on 1.2 and 2.4 GHz. (left) This 3/4" cube contains a color camera c/w microphone. I had been working with 1.2 & 2.4 GHz FM ATV equipment so simply assumed these cameras were FM also. After trying to receive them with no luck using a Comtech FM They may look large here but inside the camera with audio was a tiny Audio & Video RF Modulator Board, Microphone and Camera Board. Remember, these boards are slightly more than 1/2" square. There are many versions of these cameras available so make sure you know what you are ordering if you don't want to be disappointed. The three units I had a chance to play with were pretty basic. More expensive versions have features that I would certainly recommend. Lighting was ok in rooms with a large window during the daytime and in my very well lit workshop, but at night lighting in most of my house was insufficient to provide a usable picture.

Many of these inexpensive cameras appear to only be designed to accommodate room lighting levels but this is seldom mentioned in advertisements. Only one of these three cameras was usable in full outdoor lighting. The receivers required frequent fine tuning, especially after first being turned on. The cameras had very simple transmitters with no frequency control and drifted with temperature and battery voltage. And the receivers had no automatic frequency control so they also drifted due to, in addition to other things, a variable tuning voltage derived from the temperature dependent 5 volt regulator. Better receivers are available that have automatic frequency control. Best would be units using FM modulation so look for cameras with receivers that feature, usually four, 2.4 GHz switch selectable channels. I have limited experience with everything available, but this should at least get you a FM unit.

The good things about Television

Over the years, Television has become omnipresent in the everyday life of people. Whether you live in London, Paris or Tokyo, this tool is an important feature of the modern culture and can be reached everywhere. From news, movies, music to sports, entertainment and education, there is something for everyone. You can spend a lazy afternoon after work in front of the TV and discover multiple opportunities for relaxation. Make some popcorn and keep yourself busy.

With so many types of TV transmitters available today, there is no wonder so many people have access to it. As evenings are perfect for family times, you and your children can watch an interesting film, while you talk about each other’s day. Cherish the moments you sit back and enjoy their company. Call your friends over when your beloved soccer team has a match and have some fun together. You can discuss its intense moments during break time and strengthen your bond.

There is nothing more exciting than a shared TV series with somebody you care for. You can plan a date night at home and pick a popular TV show that appeals to both you and your escort. Discover enigmatic worlds with amazing characters or stories which portray daily life situations. This way, you can exercise and develop your basic values. Because good quality antennas give you a high-definition resolution from all the famous networks, make sure you select a proper one.

Television is a powerful medium for education and culture. You can watch documentaries and educational programming which will teach you or your kids about history, animals, planets, science, art, music and much more. Expand your knowledge and learn life lessons or more things about the society you live in. The news programs and talk-shows can help you relate to other cultures and individuals. You can also travel to places you have never been before or you did not know they existed.

While lives have become extremely busy in the last decade, there is less room left for leisure times when you can rest and have a good laugh. TV can give you the best medicine for your bad mood and fatigue. Browse through numerous comedies available and choose the one you prefer. There are plenty of hilarious stories with magnificent actors that will make you forget about every worry. When you feel down turn on your TV and enjoy a good comedy.

In case you want to feel the thrills of suspense and competitions, contest shows like “The Voice” or “Survivor” are a good choice for you. Do not miss on any edition, root for your favored candidate and feel the excitement of the contestants. Keep in mind that television also makes your workout sessions easier. When you run on the treadmill, you might get bored and tired sooner. Keep your TV close by and let it distract you from the strenuous activity.

The TV is a wonderful instrument for those who seek tension relief techniques and look for a good mood enhancer. Reconnect with your family members of all ages and find out about the best solutions for your problems from informative shows. Let your children pay attention to cartoons while you do your chores around the house. Explore the countless channels and let the television enrich your life!