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A simple garden lighting scheme usually consists of four stages which are as follows:
- To start with the garden Lighting Scheme must be protected by an RCD either within the fuse board or an RCD spurred from an existing circuit.
- The second stage is to decide how to switch the lights on and off. You have a variety of options for this stage including house switch, remote control, timer, photocell and PIR.
- The third stage is to run a suitable cable in to the garden. Armoured cable is the only cable we recommend due to the protection it provides and its ability to increase safety by earthing the armoured strands via armoured glands therefore if something where to penetrate the cable the earth would be already be connected thus facilitating a trip in the RCD.
- The next and final stage of the process is to terminate the armoured around the garden in suitable positions for junction boxes either for transformers or mains lighting. From this stage all the lights should be in position ready to connect up back to the junction areas.
A residual current device (RCD) is similar to that of a residual current circuit breaker (RCCB), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the phase "live" conductor and the neutral conductor. Such an imbalance is sometimes caused by current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions; RCDs are designed to disconnect quickly enough to mitigate the harm caused by such shocks. In all residential homes RCD'S must operate at no less than 30ms.
Differences clarified by BS 7671:2008:
By definition an RCD is a mechanical switching device or association of devices intended to cause the opening of the contacts when the residual current attains a given value under specific conditions.
The watt(symbol: W) is the SI derived unit of power, equal to one joule of energy per second. It measures a rate of energy conversion.
A human climbing a flight of stairs is doing work at a rate of about 200 watts. A typical automobile engine produces mechanical energy at a rate of 25,000 watts (approximately 33.5 horsepower) while cruising. A typical household incandescent light bulb uses electrical energy at a rate of 25 to 100 watts, while compact fluorescent lights typically consume 5 to 30 watts.
Voltage/Electrical tension (or voltage after its SI unit, the volt) is the difference of electrical potential between two points of an electrical or electronic circuit, expressed in volts.[1] It is the measurement of the potential for an electric field to cause an electric current in an electrical conductor. Depending on the difference of electrical potential it is called extra low voltage, low voltage, high voltage or extra high voltage. Specifically, voltage is equal to energy per unit charge.
Voltage drop is the reduction in voltage in an electrical circuit between the source and load. In electrical wiring national and local electrical codes may set guidelines for maximum voltage drop allowed in a circuit, to ensure reasonable efficiency of distribution and proper operation of electrical equipment (the maximum permitted voltage drop varies from one country to another)[1].
Voltage drop may be neglected when the impedance of the interconnecting conductors is small relative to the other components of the circuit.
For example, an electric space heater may very well have a resistance of ten ohms, and the wires which supply it may have a resistance of 0.2 ohms, about 2% of the total circuit resistance. This means that 2% of the supplied voltage is actually being lost by the wire itself.
Excessive voltage drop will result in unsatisfactory operation of electrical equipment, and represents energy wasted in the wiring system. Voltage drop can also cause damage to electrical motors.
In electronic design and power transmission, various techniques are used to compensate for the effect of voltage drop on long circuits or where voltage levels must be accurately maintained. The simplest way to reduce voltage drop is to increase the diameter of the conductor between the source and the load which lowers the overall resistance.
Transformer is a device that transfers electrical energy from one circuit to another through inductively coupled electrical conductors. A changing current in the first circuit (the primary) creates a changing magnetic field. This changing magnetic field induces a changing voltage in the second circuit (the secondary). This effect is called mutual induction.
If a load is connected to the secondary circuit, electric charge will flow in the secondary winding of the transformer and transfer energy from the primary circuit to the load connected in the secondary circuit.
The secondary induced voltage VS, of an ideal transformer, is scaled from the primary VP by a factor equal to the ratio of the number of turns of wire in their respective windings:
By appropriate selection of the numbers of turns, a transformer thus allows an alternating voltage to be stepped up - by making NS more than NP - or stepped down, by making it less.
Transformers are some of the most efficient electrical 'machines', with some large units able to transfer 99.75% of their input power to their output. Transformers come in a range of sizes from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge units weighing hundreds of tons used to interconnect portions of national power grids. All operate with the same basic principles, although the range of designs is wide.
Solid-state lighting (SSL) refers to a type of lighting that utilizes light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, plasma (used in arc lamps such as fluorescent lamps), or gas.
The term "solid state" refers to the fact that light in an LED is emitted from a solid object - a block of semiconductor - rather than from a vacuum or gas tube, as is the case in traditional incandescent light bulbs and fluorescent lamps. Compared to incandescent lighting, however, SSL creates visible light with reduced heat generation or parasitic energy dissipation, similar to that of fluorescent lighting. In addition, its solid-state nature provides for greater resistance to shock, vibration, and wear, thereby increasing its lifespan significantly.
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