The situation, when the incandescent lamp breaks down and at the same time a lot of dangerous fragments are scattered around the room, is by no means new. And it can happen both with a long working copy, and with the recently installed. They burn out at the moment they are switched on, because for a very short time( literally tenths of a second), the current that comes to the filament is much higher than its nominal value, but this is enough to make it burn out.
To correct the situation, will smoothly turn on incandescent lamps , the basis of which is a device - a protection unit that allows to provide a fairly slow( 2-3 sec.) Ignition of a tungsten spiral. You can make it yourself, or you can buy it in ready-made form.
Features of the choice of the
protection unit When choosing such a device, it is necessary to take into account the total value of the load, which can be easily calculated taking into account the number of incandescent lamps and their power. This value requires a power reserve, it is better if this value is about a quarter of the value obtained. This will extend the life of the device, ensuring a smooth inclusion of incandescent lamps. Overloading the unit is unacceptable, as this will cause a significant overheating of all the elements, and it will quickly break down.
One of the acceptable options is the Uniel Upb-200W-BL .To it it is possible to connect fluorescent lamps with total power not more than 160W.Only it should be borne in mind that the use of the protective block leads to a drop in voltage, so the load is noticeably reduced and is only 171V.
Given this feature, you need to use lamps with more power and in accordance with it to choose a protection unit.
The principle of its operation is simple: a voltage is applied to the lamp, which gradually increases to a normal level within a few seconds. This significantly reduces the amount of starting current, which allows to increase the duration of incandescent lamps.
Self-made protection unit
The scheme for smooth switching on of incandescent lamps is not very complicated, but you must take into account a lot of features, while observing all the current standards for electrical devices. But not all schemes give the desired result, so let's give one of the most interesting variants of such a product.
Schematic of smooth switching on of incandescent lamps - Photo 01
This scheme of smooth switching on incandescent lamps demonstrates the switching on of the lamp and the device, and the polarity of the wires is not very important. But it is important to connect this device to the phase wire break, thus providing a serial connection to the switch, which must be one-key. Here are the explanations for the scheme:
- Field-effect transistor in the initial cycle of the device is in a closed state and it is on it that the stabilization voltage drops, since it is part of the diagonal of the diode bridge. At this time, the lamp does not light.
- The capacitor C1 begins to charge when the voltage is applied through the resistor( R1) and the diode( VD1) until it reaches the level of 9.1V, which can not be exceeded because it is limited by the zener diode.
- When the voltage reaches a predetermined level, a gradual opening of the transistor will start, accompanied by an increase in the current values, while the voltage in the drain will decrease. A smooth ignition of the filament of the lamp will begin.
- The presence of a second resistor is necessary because it allows the capacitor to be discharged after the lamp power is turned off. At this time, the voltage on the drain will be small - about 0.85V at current strength of 1A.
It is very important that such a scheme of smooth switching of incandescent lamps ensures the operation without flicker, which is very important for the comfort of staying indoors. It can be used for lamps operating, both from the standard voltage in 220V, and from a lower one.
Where to install the protection devices
The small dimensions of this device allow mounting them in different places, but you need to provide unimpeded access to it, if you need a repair or a complete replacement.
It is equally important to provide the device with air supply, which is necessary for cooling its elements, which should ensure smooth switching on of incandescent lamps. To do this, there must be slits or holes in its case, which must be taken into account when creating such devices with your own hands.
The most common locations are:
- On the ceiling. This option is most common. In this case, it is installed in the base of the lighting device or in close proximity to it.
- In the socket of the switch , the switch box.
Wiring diagram of the protection unit, in the switch compartment, for lamps 220( V) - Photo 02
The devices for the protection of incandescent lamps can significantly increase their life, but to install them, and even more to design, it is necessary to comply with the rules and regulations, and at leastinitial knowledge in the field of installation of electrical appliances. Otherwise, to carry out such work, it is advisable to invite the pros.
