LIGHT IN THE GREENHOUSE

LIGHT IN THE GREENHOUSEThe cultivation of vegetables and seedlings in early spring in the middle lane requires greenhouse lighting. According to the current standards plants must be under day or artificial light for at least 10-12 hours a day. Longer lighting is not recommended as it may adversely affect the development of plants.
To provide artificial light and vegetable seedlings in greenhouses on garden plots typically use fluorescent lamps as the most economical and gives spectrum of light, close to daylight.
 
Commercially available range of lamps and some of their characteristics are given in table 2.
 
Table 1. Technical characteristics of fluorescent lamps.
Table 1. Technical characteristics of fluorescent lamps.
 
Table 2. Characteristics of the circuit elements for lamps of different power.
Table 2. Characteristics of the circuit elements for lamps of different power.
Most suitable for lighting plants its characteristics are the bulb brands LDTS and LD.
 
The usual circuit of the lamp (Fig. 1) not allow to use fully the capabilities of the lamps; the inclusion of the additional capacitor is C2-4 UF (for lamps LDC or LD with a capacity of 30 and 40 W) increases the light output of the lamp.
 
Fig. 1. The standard circuit of switching-on of fluorescent lamps.
Fig. 1. The standard circuit of switching-on of fluorescent lamps.
 
Fig. 2. The scheme of inclusion of fluorescent lamps in blown filaments.
Fig. 2. The scheme of inclusion of fluorescent lamps in blown filaments.

 
Figure 2 shows the circuit of the fluorescent lamps that have burned out filament ignition. Characteristics of the circuit elements for lamps of different power are shown in table 2.
 
A. VINOGRADOV

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