Fluorescent lamps have long been widely used both in everyday life and in other (very different) areas: lighting in production and in public institutions, operating rooms, light outdoor and indoor advertising , etc.
"Pros" of fluorescent lighting
Compared to incandescent lamps, fluorescent lighting devices have a number of indisputable advantages:
- high light intensity with a wide range of light distribution;
- increased reliability of lighting devices;
- a wide range of temperature conditions in which fluorescent lamps can work without interruption;
- low own heating of the lamp housing or other lighting device;
- light emission in a strictly defined spectrum and mode, sparing for the eyes;
- excellent performance and wear resistance - up to 20 thousand working hours.
Auxiliary elements
Uninterrupted operation of lighting devices are designed to provide such details as a starter and a throttle.
A starter for fluorescent lamps is necessary when providing "ignition" in them of electrical discharges. If the device is in the off state, the starter is not closed. The process of closing occurs at the time of supply to the circuit of electricity. Then, when the lamp is lit, the voltage in it “disappears”, and the starter returns to its original (idle) state.
A choke is an inductive coil in which a core in a metal frame is inserted. Usually for lamps, it is selected with the same power as the device itself for lighting. Otherwise, the lamps face overload and failure much earlier than the set time.
The role of the inductor is to limit the current supply to the level that is required by a particular lighting device.
Throttle function
The choke for fluorescent lamps has several important functions. Firstly, it provides ignition of the filament, and secondly, the required current power is regulated . In a lighting fixture, it is a kind of ballast, taking on extra watts in an electrical circuit. According to the level of absorbed power, this element is divided into three groups:
- choke for class D fluorescent lamps with an average absorption level;
- Class C - low;
- Class B - Super-Low.
A high-quality choke for fluorescent lamps, the power of which is from 36 to 40 watts, takes about 6 watts, i.e. 15% of the total capacity. And the lower the lamp power, the more significant it is the difference with the throttle indicators. Therefore, the luminous efficiency of a lighting device in real conditions is always somewhat less than those parameters that are indicated in the instructions for them.
The inductor for fluorescent lamps creates a phase shift effect between voltage and current. Power networks create a voltage in the form of a sine. In ordinary incandescent lamps, the shape is the same. But in luminescent "throttle" current lags behind the main one (and the graph of the curves is already different).
As an alternative, in many designs of lighting fixtures and advertising stands, the starter and inductor for fluorescent lamps is replaced by a special device that converts electrical frequencies at the automation level. It “starts” the lamp at any external temperature, increases the stability of work and the intensity of light emission. Devices with such a device work much longer.
Thus, electronic ballast can have several types and different performance. Naturally, this affects the cost of the devices.