Electronic ballast: ways to implement electronic ballast for fluorescent lamps, device diagrams

The main factor in the normal operation of fluorescent lamps is the type of electrical current. Since these lighting devices operate on a constant electric current, a ballast or ballast must be installed in their circuit. The most popular is the electronic ballast, which has a number of advantages over an electromagnetic unit.

Main varieties

Today there are two types of ballast - electromagnetic and electronic. They differ in how they work, so it's worth getting to know each of them.

Electromagnetic ballast

This type of implementation involves the serial connection of the choke to the lamp. Also, for the operation of the electromagnetic ballast, a starter is required, with the help of which the ignition process of the lamp is regulated. This part is a gas-discharge lamp with bimetallic electrodes inside the bulb.

The device works as follows:

1. When voltage is applied to the starter, the bimetallic electrodes are closed from heating. This leads to an increase in the current strength, since it can only be limited by the internal resistance of the choke windings.
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2. With an increase in the electric current index, the electrodes of the fluorescent lamp begin to warm up.
3. When the starter cools down, the bimetallic electrodes open.
4. At the moment the circuit is broken by the starter, a high voltage pulse arises in the choke coil, which leads to the ignition of the lighting device.

When the luminescent device goes into normal operation, the voltage across it and the starter turns out to be 50% less than the mains voltage, and this is not enough to trigger the second element. As a result, the starter goes into a disabled state and ceases to affect the operation of the lighting fixture.

The electromagnetic ballast features low cost and simple design. For a long time, these devices were actively used in the manufacture of lamps, however, they have several disadvantages:

1. It takes about 3 seconds for the luminescent device to go into operation.
2. Lighting devices with electromagnetic ballast flicker during operation, which negatively affects the organs of vision.
3. The power consumption of these devices is significantly higher compared to electronic ballast.
4. The throttle makes noise during operation.

Due to these shortcomings, electromagnetic ballast for lamps is rarely used today.

Electronic implementation

Electronic devices are voltage converters that provide power to fluorescent lamps. Although many variants of electronic ballast have been developed, in most cases a single block diagram is used. At the same time, manufacturers can make certain changes to it, for example, add a scheme for controlling the brightness of the lighting fixture.

Transferring the fluorescent lamp of the lamp to the normal operating mode using an electronic Control gear is most often carried out in one of two ways:

1. Until the ignition voltage is applied to the cathodes of the lamp, they are preheated. This allows you to get rid of flicker, as well as increase the efficiency of the lighting fixture.
2. An oscillating circuit is installed in the design of the lamp, which enters into resonance before a discharge appears in the lamp bulb.

When using the second method, the electronic ballast circuit is implemented in such a way that the filament of the bulb is part of the circuit. As soon as a discharge appears in a gaseous medium, the parameters of the oscillatory circuit change, after which it goes out of resonance. As a result, the voltage is reduced to the working one.

Schematic of a ballast for 36w lamps.

Today, compact fluorescent devices with an E14 and E27 base are widely used. In them, the ballast is installed directly into the structure of the device. An example of an electronic ballast circuit for 18w fluorescent lamps is shown below.

Troubleshooting and repair

If there are problems with the operation of discharge lamps, often repairs can be carried out independently. The main task in such a situation is identifying the source of the problem - lighting fixture or ballast. To check the electronic circuit, you must first remove the linear lamp, close the electrodes and connect an ordinary lamp. If it starts to glow, then the problem is not in the ballast.

To find a malfunction in fluorescent lighting devices, you first need to ring all the elements one by one, starting with the fuse. If this part turns out to be working, it is necessary to proceed to checking the capacitor and diodes. If all the elements of the ballast turned out to be in good order, it is worth checking the throttle. Timely repair of the lighting device will increase its service life.