Lighting circuits

The current m.-iy be obtained from a number of secondary batteries or from n. direct electric light circuit with a suitable resistance. 

Colloidal platinum may be prepared very easily by arcing under distilled water between platinum electrodes (Fig. 24). The current is taken from an ordinary 110-volt lighting circuit through an ammeter and an adjustable resistance in series or simply through a known... 

They also conceived the idea of energizing a dynamic type of loud speaker from an alternating current house-lighting circuit, and reduced the invention to practice on Jan. 25, 1922. On March 21, 1922, they filed an application for a power amplifier. The conception embodied in this patent was devised by the patentees without suggestion, instruction, or assignment from any superior. 

The triplet harmonics, including the 3rd, 9th, and 15th, exists only in circuits that have a neutral conductor such as computer circuits and lighting circuits. The triplet harmonics that exist on the secondary side of a A — T transformer will not be transformed to the primary side of the transformer. Transformers with K ratings of 4—50 are specifically designed to handle these harmonic currents. 

When designing a lighting circuit it is customary practice to size the cables so that the farthest lamp from the supply receives no less than 95% of its nominal voltage. In addition it is assumed that all the hghting fittings are energised when this design calculation is made. 

A post-accident investigation discovered that the indicator light circuit was wired to indicate presence of power at the valve, but it did not indicate valve position. Thus, the indicator showed only that the activation button had been pushed, not that the... 

Provide automatic switching on in case of power failure in the lighting circuit. Provision of electric supply from separate feeders for alternate light fitting so that in case of failure of a particular feeder, there will still be some light available. 

Fig. 9 Microscopy images of a reconfigurable light circuit for dual-channel spectroscopy with integrated optofluidic switch [7]...

When we open the switch of an inductive circuit such as an electric motor or fluorescent light circuit the magnetic flux collapses and produces an arc across the switch contacts. The arc is produced by the stored magnetic energy being discharged across the switch contacts. 

A 6 A Type B MCB to BS EN 60898 which is used to protect a domestic lighting circuit will trip within 0.4s when 6A times a multiple of 5, that is, 30 A, flows under fault conditions. 

An electrical installation is made up of many different electrical circuits, lighting circuits, power circuits, single-phase domestic circuits and three-phase industrial or commercial circuits. 

Table A1 in Appendix A of the On Site Guide deals with the assumed current demand of points, and states that for lighting outlets we should assume a current equivalent to a minimum of 100 W per lamp holder. This means that for a domestic lighting circuit rated at 5 A, a maximum of 11 lighting outlets could be connected to each circuit. In practice, it is usual to divide the fixed lighting outlets into a convenient number of circuits of seven or eight outlets each. In this way the whole installation is not plunged into darkness if one lighting circuit fuses and complies with Regulation 314.1 which tells us to divide into circuits to minimize inconvenience and avoid danger .

Lighting circuits are usually wired in 1.0 or 1.5 mm cable using either a loop-in or joint-box method of installation. The loop-in method is universally employed with conduit installations or when access from above or below is prohibited after installation, as is the case with some industrial installations or blocks of flats. In this method the only joints are at the switches or lighting points, the live conductors being looped from switch to switch and the neutrals from one lighting point to another. 

Proper functioning of all lighting circuits, Headlight beam aim. including emergency flashers. 

Lighting circuits are usually wired in 1.0 or 1.5 mm cable using either a loop-in or joint-box method of installation. The loop-in method is universally employed with conduit installations or when access from above... 

Regulation 525 states that the drop in voltage from the supply terminals to the fixed current-using equipment must not exceed 3% for lighting circuits and 5% for other uses of the mains voltage. That is a maximum of 6.9V for lighting and 11.5V for other uses on a 230V installation. The volt drop for a particular cable may be found from ... 

The main lighting circuit in a room having only one entrance would... 

Consider the case of a connector for a gas valve that the manufacturer includes with the valve. When in place, the connector joins two screws that are part of the pilot light circuit. A thermocouple heated by the pilot light creates a current to operate the protective circuit. 

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