Lamps daylight(LDS) are widely used for lighting both large areas of public buildings and as household light sources. The popularity of fluorescent lamps is largely due to their economic characteristics. Compared to incandescent lamps of this type lamps have high efficiency, increased light output and longer service life. However, a functional disadvantage of fluorescent lamps is the need for a starting starter or a special ballast (ballast). Accordingly, the task of starting the lamp when the starter fails or is absent is urgent and relevant.

The fundamental difference between an LDS and an incandescent lamp is that the conversion of electricity into light occurs due to the flow of current through mercury vapor mixed with an inert gas in a bulb. Current begins to flow after breakdown of the gas by high voltage applied to the electrodes of the lamp.

1. Throttle.
2. Lamp bulb.
3. Luminescent layer.
4. Starter contacts.
5. Starter electrodes.
6. Starter housing.
7. Bimetallic plate.
8. Lamp filaments.
9. Ultraviolet radiation.
10. Discharge current.

The resulting ultraviolet radiation lies in the part of the spectrum invisible to the human eye. To convert it into a visible light flux, the walls of the bulb are coated with a special layer, a phosphor. By changing the composition of this layer, you can obtain different light shades.
Before the direct launch of the LDS, the electrodes at its ends are heated by passing a current through them or due to the energy of a glow discharge.
High breakdown voltage is provided by ballasts, which can be assembled according to a well-known traditional circuit or have a more complex design.

Starter operating principle

In Fig. Figure 1 shows a typical connection of an LDS with a starter S and a choke L. K1, K2 – lamp electrodes; C1 is a cosine capacitor, C2 is a filter capacitor. A mandatory element of such circuits is a choke (inductor) and a starter (chopper). The latter is often used as a neon lamp with bimetallic plates. To improve the low power factor due to the presence of inductor inductance, an input capacitor is used (C1 in Fig. 1).

Rice. 1 Functional diagram of LDS connection

The LDS startup phases are as follows:
1) Warming up the lamp electrodes. In this phase, the current flows through the circuit “Network – L – K1 – S – K2 – Network”. In this mode, the starter begins to close/open randomly.
2) At the moment the circuit is broken by the starter S, the magnetic field energy accumulated in the inductor L is applied in the form of high voltage to the electrodes of the lamp. An electrical breakdown of the gas inside the lamp occurs.
3) In breakdown mode, the lamp resistance is lower than the resistance of the starter branch. Therefore, the current flows along the circuit “Network – L – K1 – K2 – Network”. In this phase, inductor L acts as a current-limiting reactor.
Disadvantages of the traditional LDS starting circuit: acoustic noise, flickering with a frequency of 100 Hz, increased start-up time, low efficiency.

Operating principle of electronic ballasts

Electronic ballasts (EPG) use the potential of modern power electronics and are more complex, but also more functional circuits. Such devices allow you to control the three startup phases and adjust the light output. The result is longer lamp life. Also, due to the lamp being powered with a current of a higher frequency (20÷100 kHz), there is no visible flicker. A simplified diagram of one of the popular electronic ballast topologies is shown in Fig. 2.

Rice. 2 Simplified circuit diagram of electronic ballasts
In Fig. 2 D1-D4 – rectifier mains voltage, C – filter capacitor, T1-T4 – transistor bridge inverter with transformer Tr. Optionally, the electronic ballast may contain an input filter, a power factor correction circuit, additional resonant chokes and capacitors.
A complete schematic diagram of one of the typical modern electronic ballasts is shown in Fig. 3.

Rice. 3 Diagram of BIGLUZ electronic ballasts
The circuit (Fig. 3) contains the main elements mentioned above: a bridge diode rectifier, a filter capacitor in the link direct current(C4), an inverter in the form of two transistors with wiring (Q1, R5, R1) and (Q2, R2, R3), inductor L1, transformer with three terminals TR1, starting circuit and resonant circuit of the lamp. Two windings of the transformer are used to turn on transistors, the third winding is part of the resonant circuit of the LDS.

Methods for starting LDS without specialized ballasts

When a fluorescent lamp fails, there are two possible reasons:
1) . In this case, it is enough to replace the starter. The same operation should be carried out if the lamp flickers. In this case, upon visual inspection, there are no characteristic darkening on the LDS flask.
2) . Perhaps one of the electrode threads has burned out. Upon visual inspection, darkening may be noticeable at the ends of the bulb. Here you can use known starting circuits to continue operating the lamp even with burnt-out electrode threads.
For emergency starting, a fluorescent lamp can be connected without a starter according to the diagram below (Fig. 4). Here the user plays the role of starter. Contact S1 is closed for the entire period of lamp operation. Button S2 is closed for 1-2 seconds to light the lamp. When S2 opens, the voltage on it at the moment of ignition will be significantly higher than the mains voltage! Therefore, extreme caution should be exercised when working with such a scheme.

Rice. 4 Schematic diagram starting the LDS without a starter
If you need to quickly ignite an LVDS with burnt filaments, then you need to assemble a circuit (Fig. 5).

Rice. 5 Schematic diagram of connecting an LDS with a burnt filament
For a 7-11 W inductor and a 20 W lamp, the C1 rating is 1 µF with a voltage of 630 V. Capacitors with a lower rating should not be used.
Automatic circuits for starting an LDS without a choke involve using an ordinary incandescent lamp as a current limiter. Such circuits, as a rule, are multipliers and supply the LDS with direct current, which causes accelerated wear of one of the electrodes. However, we emphasize that such circuits allow you to run even an LDS with burnt-out electrode threads for some time. Typical scheme connection of a fluorescent lamp without a choke is shown in Fig. 6.

Rice. 6. Structural scheme connecting LDS without a choke

Rice. 7 Voltage on the LDS connected according to the diagram (Fig. 6) before start-up
As we see in Fig. 7, the voltage on the lamp at the moment of starting reaches the level of 700 V in approximately 25 ms. Instead of an HL1 incandescent lamp, you can use a choke. Capacitors in the diagram of Fig. 6 should be selected within 1÷20 µF with a voltage of at least 1000V. Diodes must be designed for reverse voltage 1000V and current from 0.5 to 10 A depending on the lamp power. For a 40 W lamp, diodes rated for current 1 will be sufficient.
Another version of the launch scheme is shown in Fig. 8.

Rice. 8 Schematic diagram of a multiplier with two diodes
Parameters of capacitors and diodes in the circuit in Fig. 8 are similar to the diagram in Fig. 6.
One of the options for using a low-voltage power supply is shown in Fig. 9. Based on this circuit (Fig. 9), you can assemble a wireless fluorescent lamp on a battery.

Rice. 9 Schematic diagram of connecting LDS from a low-voltage power source
For the above circuit, it is necessary to wind a transformer with three windings on one core (ring). As a rule, the first one is wound primary winding, then the main secondary (indicated in the diagram as III). Cooling must be provided for the transistor.

Conclusion

If the fluorescent lamp starter fails, you can use an emergency “manual” start or simple DC power circuits. When using circuits based on voltage multipliers, it is possible to start a lamp without a choke using an incandescent lamp. When operating on direct current, there is no flicker or noise from the LDS, but the service life is reduced.
If one or two filaments of the cathodes of a fluorescent lamp burn out, it can continue to be used for some time, using the above-mentioned circuits with increased voltage.

Recently I looked at a whole box of burnt energy saving lamps, mostly with good electronics, but burnt-out fluorescent lamp filaments, and I thought - I need to use all this stuff somewhere. As you know, LDS with burnt filaments must be powered with rectified mains current using a starterless starting device. In this case, the filaments of the lamp are shunted with a jumper and to which the high voltage to turn on the lamp. There is an instantaneous cold ignition of the lamp, with a sharp increase in voltage across it, upon start-up without preheating the electrodes.

And although ignition with cold electrodes is a more difficult mode than ignition in the usual way, this method allows you to use a fluorescent lamp for lighting for a long time. As you know, igniting a lamp with cold electrodes requires increased voltage up to 400...600 V. This is realized by a simple rectifier, the output voltage of which will be almost twice as high as the input network 220V. An ordinary low-power incandescent light bulb is installed as a ballast, and although using a lamp instead of a choke reduces the efficiency of such a lamp, if we use incandescent lamps with a voltage of 127 V and connect it to the DC circuit in series with the lamp, we will have sufficient brightness.

Any rectifier diodes, for voltage from 400V and current 1A, you can also use Soviet brown KTs-shki. Capacitors also have an operating voltage of at least 400V.

This device works as a voltage doubler, output voltage which is applied to the cathode - anode of the LDS. After the lamp is ignited, the device switches to full-wave rectification mode with active load and the voltage is equally distributed between lamps EL1 and EL2, which is true for LDS with a power of 30 - 80 W, having an operating voltage on average of about 100 V. With this circuit turned on, the luminous flux of an incandescent lamp will be approximately a quarter of the flux of the LDS.

A 40 W fluorescent lamp requires a 60 W, 127 V incandescent lamp. Its luminous flux will be 20% of the LDS flux. And for an LDS with a power of 30 W, you can use two 127 V incandescent lamps of 25 W each, connecting them in parallel. The luminous flux of these two incandescent lamps is about 17% of the luminous flux of an LDS. This increase in the luminous flux of an incandescent lamp in a combination luminaire is explained by the fact that they operate at a voltage close to the rated voltage, when their luminous flux approaches 100%. At the same time, when the voltage on an incandescent lamp is about 50% of the rated one, their luminous flux is only 6.5%, and the power consumption is 34% of the rated one.

The switching circuit for fluorescent lamps is much more complex than that of incandescent lamps.
Their ignition requires the presence of special starting devices, and the life of the lamp depends on the quality of these devices.

To understand how launch systems work, you must first become familiar with the design of the lighting device itself.

A fluorescent lamp is a gas-discharge light source, the luminous flux of which is formed mainly due to the glow of a phosphor layer applied to the inner surface of the bulb.

When the lamp is turned on, an electronic discharge occurs in the mercury vapor that fills the test tube and the resulting UV radiation affects the phosphor coating. With all this, the frequencies of invisible UV radiation (185 and 253.7 nm) are converted into visible light radiation.
These lamps have low energy consumption and are very popular, especially in industrial premises.

Scheme

When connecting fluorescent lamps, a special starting and regulating technique is used - ballasts. There are 2 types of ballasts: electronic - electronic ballast (electronic ballast) and electromagnetic - electromagnetic ballast (starter and choke).

Connection diagram using electromagnetic ballast or electronic ballast (throttle and starter)

A more common connection diagram for a fluorescent lamp is using an electromagnetic amplifier. This starter circuit.

Operating principle: when the power supply is connected, a discharge appears in the starter and
the bimetallic electrodes are short-circuited, after which the current in the circuit of the electrodes and the starter is limited only internal resistance choke, as a result of which the operating current in the lamp increases almost three times and the electrodes of the fluorescent lamp instantly heat up.
At the same time, the bimetallic contacts of the starter cool down and the circuit opens.
At the same time, the choke breaks, thanks to self-induction, creates a triggering high-voltage pulse (up to 1 kV), which leads to a discharge in the gas environment and the lamp lights up. After which the voltage on it will become equal to half of the mains voltage, which will not be enough to re-close the starter electrodes.
When the lamp is on, the starter will not participate in the operating circuit and its contacts will and will remain open.

Main disadvantages

• Compared to a circuit with electronic ballast, electricity consumption is 10-15% higher.

• Long start-up of at least 1 to 3 seconds (depending on lamp wear)

• Inoperability at low ambient temperatures. For example, in winter in an unheated garage.

• The stroboscopic result of a flashing lamp, which has a bad effect on vision, and the parts of machine tools rotating synchronously with the mains frequency appear motionless.

• The sound of the throttle plates humming, growing over time.

Switching diagram with two lamps but one choke. It should be noted that the inductance of the inductor must be sufficient for the power of these two lamps.
It should be noted that in a sequential circuit for connecting two lamps, 127 Volt starters are used; they will not work in a single-lamp circuit, which will require 220 Volt starters

This circuit, where, as you can see, there is no starter or throttle, can be used if the filaments of the lamps have burned out. In this case, the LDS can be ignited using step-up transformer T1 and capacitor C1, which will limit the current flowing through the lamp from a 220-volt network.

This circuit is suitable for the same lamps whose filaments have burned out, but here there is no need for a step-up transformer, which clearly simplifies the design of the device

But such a circuit using a diode rectifier bridge eliminates the flickering of the lamp at the mains frequency, which becomes very noticeable as it ages.

or more difficult

If the starter in your lamp has failed or the lamp is constantly blinking (along with the starter if you look closely under the starter housing) and there is nothing at hand to replace it, you can light the lamp without it - enough for 1-2 seconds. short-circuit the starter contacts or install button S2 (caution of dangerous voltage)

the same case, but for a lamp with a burnt-out filament

Connection diagram using electronic ballast or electronic ballast

An electronic ballast (EPG), unlike an electromagnetic one, supplies the lamps with a high-frequency voltage from 25 to 133 kHz rather than the mains frequency. And this completely eliminates the possibility of lamp flickering noticeable to the eye. The electronic ballast uses a self-oscillator circuit, which includes a transformer and an output stage using transistors.

Well of course about " eternal lamp"This is a loud word, but here's how to "revive" a fluorescent lamp with burnt-out filaments quite possible...

In general, everyone has probably already understood that we are not talking about an ordinary incandescent light bulb, but about gas-discharge light bulbs (as they were previously called “fluorescent lamps”), which looks like this:

The operating principle of such a lamp: due to a high-voltage discharge, a gas (usually argon mixed with mercury vapor) begins to glow inside the lamp. In order to light such a lamp, a fairly high voltage is required, which is obtained through a special converter (ballast) located inside the housing.

useful links for general development : self-repair of energy-saving lamps, energy-saving lamps - advantages and disadvantages

The standard fluorescent lamps used are not without drawbacks: during their operation, the buzzing of the choke can be heard, the power system has a starter that is unreliable in operation, and most importantly, the lamp has a filament that can burn out, which is why the lamp has to be replaced with a new one.

But there is also Alternative option: the gas in the lamp can be ignited even with broken filaments - to do this, simply increase the voltage at the terminals.
Moreover, this use case also has its advantages: the lamp lights up almost instantly, there is no buzzing during operation, and a starter is not needed.

To light a fluorescent lamp with broken filaments (by the way, not necessarily with broken filaments...), we need a small circuit:

Capacitors C1, C4 must be paper, with an operating voltage of 1.5 times the supply voltage. Capacitors C2, SZ should preferably be mica. Resistor R1 must be wirewound, according to the lamp power indicated in the table

Power lamps, W	C1 -C4 µF	C2 - NW pF	D1 - D4	Ohm
		3300	D226B
		6800	D226B
		6800	D205
		6800	D231

Diodes D2, DZ and capacitors C1, C4 represent a full-wave rectifier with doubling the voltage. The values ​​of capacitances C1, C4 determine the operating voltage of lamp L1 (the larger the capacitance, the greater the voltage on the electrodes of lamp L1). At the moment of switching on, the voltage at points a and b reaches 600 V, which is applied to the electrodes of lamp L1. At the moment of ignition of lamp L1, the voltage at points a and b decreases and ensures normal operation of lamp L1, designed for a voltage of 220 V.

The use of diodes D1, D4 and capacitors C2, SZ increases the voltage to 900 V, which ensures reliable ignition of the lamp at the moment of switching on. Capacitors C2, SZ simultaneously help suppress radio interference.
Lamp L1 can work without D1, D4, C2, C3, but in this case the reliability of inclusion decreases.

Data for circuit elements depending on the power of fluorescent lamps are given in the table.

When choosing modern way lighting the room, you need to know how to connect a fluorescent lamp yourself.

The large surface area of ​​the glow helps to obtain even and diffuse illumination.

Therefore, this is exactly the option that became last years very popular and in demand.

Fluorescent lamps belong to gas-discharge lighting sources, characterized by the formation of ultraviolet radiation under the influence of an electrical discharge in mercury vapor with subsequent conversion into high visible light output.

The appearance of light is due to the presence on the inner surface of the lamp of a special substance called phosphor, which absorbs UV radiation. Changing the composition of the phosphor allows you to change the tint range of the glow. The phosphor can be represented by calcium halophosphates and calcium-zinc orthophosphates.

The principle of operation of a fluorescent light bulb

The arc discharge is supported by thermionic emission of electrons on the surface of the cathodes, which are heated by passing a current limited by the ballast.

The disadvantage of fluorescent lamps is represented by the inability to make a direct connection to electrical network, which is due to the physical nature of the lamp glow.

A significant part of luminaires intended for installation of fluorescent lamps have built-in glow mechanisms or chokes.

Connecting a fluorescent lamp

To correctly carry out independent connection, you need to choose the right fluorescent lamp.

Such products are marked with a three-digit code containing all the information about the quality of light or color rendering index and color temperature.

The first number of the marking indicates the level of color rendering, and the higher these indicators are, the more reliable color rendering can be obtained during the lighting process.

The designation of the lamp glow temperature is represented by digital indicators of the second and third order.

The most widely used is an economical and highly efficient connection based on an electromagnetic ballast, supplemented by a neon starter, as well as a circuit with a standard electronic ballast.

Connection diagrams for a fluorescent lamp with a starter

Connecting an incandescent lamp yourself is quite simple, due to the presence of all necessary elements and standard assembly diagrams.

Two tubes and two chokes

The technology and features of independent serial connection in this way are as follows:

• supply of phase wire to the ballast input;
• connecting the choke output to the first contact group of the lamp;
• connecting the second contact group to the first starter;
• connection from the first starter to the second lamp contact group;
• connecting the free contact to the wire to zero.

The second tube is connected in a similar way. The ballast is connected to the first lamp contact, after which the second contact from this group goes to the second starter. Then the starter output is connected to the second lamp pair of contacts and the free contact group is connected to the neutral input wire.

This connection method, according to experts, is optimal if there are a pair of lighting sources and a pair of connecting kits.

Connection diagram for two lamps from one choke

Independent connection from one choke is a less common, but completely uncomplicated option. This two-lamp series connection is economical and requires the purchase of an induction choke, as well as a pair of starters:

• a starter is connected to the lamps through a parallel connection to the pin output at the ends;
• sequential connection of free contacts to the electrical network using a choke;
• connecting capacitors in parallel to the contact group of the lighting device.

Two lamps and one choke

Standard switches belonging to the category of budget models are often characterized by sticking contacts as a result of increased starting currents, so it is advisable to use special high-quality versions of contact switching devices.

How to connect a fluorescent lamp without a choke?

Let's look at how fluorescent fluorescent lamps are connected. The simplest scheme chokeless connection is used even on burnt-out fluorescent lamp tubes and is distinguished by the absence of the use of an incandescent filament.

In this case, the power supply to the lighting device tube is due to the presence of an increased DC voltage through a diode bridge.

Switching on a lamp without a choke

This circuit is characterized by the presence of a conductive wire or a wide strip of foil paper, one side connected to the terminal of the lamp electrodes. For fixation at the ends of the bulb, metal clamps of the same diameter as the lamp are used.

Electronic ballast

The operating principle of a lighting fixture with electronic ballast is to pass electric current through a rectifier, followed by entry into the buffer zone of the capacitor.

In electronic ballast, along with classic starting control devices, starting and stabilization occurs through a throttle. Power depends on high frequency current.

Electronic ballast

The natural complexity of the circuit is accompanied by a number of advantages compared to the low-frequency version:

• increasing efficiency indicators;
• elimination of flickering effect;
• reduction in weight and dimensions;
• absence of noise during operation;
• increasing reliability;
• long service life.

In any case, one should take into account the fact that electronic ballasts belong to the category of pulsed devices, so turning them on without sufficient load is the main cause of failure.

Checking the performance of an energy-saving lamp

Simple testing allows you to timely identify a breakdown and correctly determine the main cause of the malfunction, and sometimes even perform the simplest repair work yourself:

• Dismantling the diffuser and carefully examining the fluorescent tube in order to detect areas of pronounced blackening. Very rapid blackening of the ends of the flask indicates burnout of the spiral.
• Checking the filaments for breaks using a standard multimeter. If there is no damage to the threads, the resistance values ​​can vary within 9.5-9.2Om.

If checking the lamp does not show malfunctions, then the lack of operation may be due to the breakdown of additional elements, including the electronic ballast and the contact group, which quite often undergoes oxidation and needs to be cleaned.

Checking the performance of the throttle is carried out by disconnecting the starter and shorting it to the cartridge. After this, you need to short-circuit the lamp sockets and measure the throttle resistance. If replacing the starter fails to achieve the desired result, then the main fault, as a rule, lies in the capacitor.

What causes danger in an energy-saving lamp?

Various energy-saving lighting devices, which have recently become very popular and fashionable, according to some scientists, can cause quite serious harm not only to the environment, but also to human health:

• poisoning with mercury-containing vapors;
• lesions of the skin with the formation of a severe allergic reaction;
• increased risk of developing malignant tumors.

Flickering lamps often cause insomnia, chronic fatigue, decreased immunity and the development of neurotic conditions.

It is important to know that mercury is released from a broken fluorescent lamp bulb, so operation and further disposal must be carried out in compliance with all rules and precautions.

A significant reduction in the service life of a fluorescent lamp, as a rule, is caused by voltage instability or malfunctions of the ballast resistance, therefore, if the electrical network is of insufficient quality, it is suggested to use conventional incandescent lamps.

Video on the topic