Many radio amateurs are switching from EMPRA, making homemade electronic ballast for fluorescent daylight sources. The diagram of the electronic ballast with the oscillograms measured at the control points is shown in the figure:
The figure below shows the oscillogram at the time of starting (lighting up) the fluorescent lamp, as well as a drawing of the printed circuit board and the appearance of the electronic ballast.
Ballast printed circuit board, its appearance and oscillogram at the time of starting the lamp
In the video below, the master who made this electronic ballast indicates the main features of the hand-made manufacture of this device:
VIDEO
Already during the beginning of the mass operation of fluorescent lamps, radio amateurs learned to extend their service life and forced fluorescent lamps to light up, in which the incandescent filaments had burned out. Ignition was provided by increasing voltage applied to the lamp electrodes.
The voltage increase is carried out according to the scheme with a full-wave multiplier on diodes and capacitors. Thus, at the moment of start-up, a voltage peak of more than 1000 V is reached at the lamp electrodes, which is sufficient for cold ionization of mercury vapor and a discharge in the gas of the bulb. Therefore, ignition and stable operation of the lamp is possible, even with burnt-out spirals.
The ratings of the lamp starter components are shown in the table below.
The main disadvantage of this circuit for starting fluorescent lamps is the high rated voltage of the capacitors - at least 600 V which makes the device quite bulky. Another disadvantage is direct current, due to which mercury vapor will accumulate near the anode, so the lamp will need to be switched periodically by removing it from the holders and wrapping it.
The resistor acts as a current limiting function, otherwise the lamp may explode. The resistor can be wound with your own hands using nichrome wire, but the same results are obtained with a properly selected incandescent lamp, in which the dissipated thermal energy will not be wasted, but will be emitted in the form of an additional glow of the light bulb.
In most cases, radio amateurs use a 127 V incandescent lamp with a power of 25-150 W instead of a resistor, combining them if necessary. The power of the lamp connected instead of the resistor must be several times higher than the power of the connected fluorescent lamp. The ratings of other elements, calculated based on the power of the fluorescent lamp, are shown in the table.
Ratings of components of the device for starting burned-out fluorescent lamps
In this table, the required resistance and power of the diffusing lamp is achieved by connecting several 127 V lamps in parallel. The diodes can be replaced with imported ones with similar characteristics. Capacitors must withstand a voltage of at least 600 V.
The need for good lighting of an amateur radio place of employment, with a sufficient luminous flux and at the same time economical, prompted, one might even say, some searches and a test of options. First I used an ordinary small lamp with a clothespin, changed it to a small tabletop fluorescent lamp, then there was an 18-watt "ceiling-wall" fluorescent lamp made in China. I liked the latter most of all, but the fastening of the lamp itself in the fittings was somewhat underestimated, literally by two or three centimeters, but they were not enough "for complete happiness". I found a way out to do the same, but in my own way. Since the operation of the existing electronic ballast did not cause any complaints, it was logical to repeat the circuit.
This is a large part of this electronic ballast, the choke and capacitor from the Chinese were not included here.
Actually, a diagram copied from a printed circuit board in good faith. The nominal value of the electronic components allowing this to be done was determined not only "by their appearance", but also by measurements, with preliminary desoldering of the components from the board. In the diagram, the value of the resistors is indicated in accordance with the color coding.Only in relation to the choke, I allowed myself not to unwind the one available to determine the number of turns, but measured the resistance of the wound wire (1.5 Ohm with a diameter of 0.4 mm) - it worked.
The drawing can be saved to a PC and enlarged
First assembly on a circuit board. I carefully selected the component ratings, regardless of the size and quantity, and was rewarded - the light came on the first time. Ferrite ring (10 x 6 x 4.5 mm) from an energy-saving light bulb, its magnetic permeability is unknown, the diameter of the wire of the coils wound around it is 0.3 mm (without insulation). The first start on a mandatory basis through a 25 W incandescent light bulb. If it is on and the luminescent initially blinks and goes out, increase (gradually) the C4 rating, when everything worked and nothing suspicious was found, and removed the incandescent lamp, then reduced its rating to its original value.
To some extent focusing on the printed circuit board of the original source, I drew a signet under the existing suitable case and electronic components.
I etched a handkerchief and assembled a diagram. I was already looking forward to the moment when I would be pleased with myself and glad to be. But, the circuit assembled on the printed circuit board refused to work. I had to delve into and engage in the selection of resistors and capacitors. At the time of installation of the electronic ballast at the site of operation, C4 had a capacity of 3n5, C5 - 7n5, R4 resistance 6 Ohm, R5 - 8 Ohm, R7 - 13 Ohm.
The lamp "fit" not only into the design, the lamp, raised all the way up, made it possible to comfortably use the shelf inside the secretaire niche. Babay brought coziness in the "room".
Dear site visitors.
Sometimes such a malfunction occurs, after installing and connecting a luminaire with two fluorescent lamps, the luminaire is working properly. Several months pass and the lamp starts to turn on with one lamp. You start scrolling the lamp in sockets, change the starter, but there is no result. What to do and how to be, how to repair a lamp with fluorescent lamps yourself?
To begin with, consider the schemes of such lamps with fluorescent lamps:
two fluorescent lamps;
two starters;
one choke;
capacitor.
The fluorescent lamp has two filament spirals. Lamps, starter and choke are connected in series in the electrical circuit. The capacitor is connected in parallel.
capacitor;
two starters;
two fluorescent lamps;
two chokes.
The connection of fluorescent lamps in Fig. 2 does not differ in any way from the connection diagram of the lamps in Fig. 1. Two wires, phase, zero have a branch in this circuit.
And the simplest circuit of a luminaire with one lamp is shown in Fig. 3, where the capacitor, lamp and starter in the circuit are connected in parallel. The choke is connected in an electrical circuit - in series.
Similar lamps are found with three lamps. The very essence of the matter is not in this, - not in the number of lamps.
The reasons for not turning on a luminaire with one lamp or a luminaire consisting of two or more lamps, when one of the lamps of the luminaire does not turn on, may be as follows:
malfunction of the lamp itself;
no contact with the throttle;
no contact with the starter;
break in the wires.
The electrical circuit of the luminaire and establish exactly where the break is located - you can check with a probe. After you have purchased the luminaire, check all the contact connections of the luminaire.
Practical example. In the room, an electrician completely carried out the installation and connection of fluorescent lamps with two lamps, after a certain time some lamps began to work with one lamp. When I began to check the contact connections of the lamps, the reason was the following - an unreliable contact connection of one of the wires with the choke. Where there was no contact with the throttle, the lamp did not turn on.
Repair of fluorescent lamps - with electronic ballast
Armstrong fluorescent ceiling recessed luminaires with electronic ballast are simple in design and convenient in that they do not require any effort during removal and installation.
recessed ceiling lamp Armstrong
electronic ballast power supply FINTAR
Here is an example from my own practice. It was necessary to fix the malfunction of the Armstrong recessed ceiling lamp.
For this, the luminaire had to be removed from the ceiling and the electrical connections had to be checked. As a result of the diagnostics, it was found that the electronic elements of the FINTAR electronic ballast are out of order - they have burned out.
It was such a power supply unit that was not on sale; I had to purchase another similar electronic ballast for a lamp for four fluorescent lamps - Navigator.
electronic ballast Navigator
If you look closely at the two power supplies, the wiring diagrams for the fluorescent lamps are different.
The question arises: How to connect the fluorescent lamps of the ceiling lamp to another power supply?
In this example, the wire connections to the fluorescent lamp holders only need to be made according to the electrical diagram of the newly installed power supply.
Accordingly, the circuit of the contact connections of the wires had to be redone, cut off in one place, and build up the wire in another. When changing the connection diagram, the wires are pre-twisted and insulated with insulating tape.
After all the connections have been made and after making sure that when the luminaire is connected to an external source of electrical energy, the socket - all four fluorescent lamps light up - the insulating tape is removed at the place of wire connections.
A piece of cambric is put on one of the wires. The connected copper wires are etched with soldering acid and then a small layer of tin is applied to the junction with a soldering iron, soldering the wires.
etching of wire connections with soldering acid followed by soldering
soldering connected wires
Further, after the soldering of the two wires is completed, a cambric is put on the junction instead of an insulating tape.
insulation of wire connections with cambric instead of insulating tape
This method of connecting wires with subsequent insulation with cambric is simpler and more reliable. If you connect two wires simply in a twist without soldering and then insulate with an insulating tape, the connection will subsequently undergo oxidation and heating of the wires.
Numbering of contact connections of wires with electronic ballast - goes from top to bottom. That is, the first and second contact wire connection must correspond to the connection of two fluorescent lamps on one side, and so on. When connecting, you need to carefully look at the electrical diagram of the power supply and follow the given execution of such connections.
contact connection of wires to the electronic power supply electronic ballast
A small layer of tin is also applied to the ends of the bare wires before connecting to the electronic power supply unit, for a high-quality connection.
In general, there is nothing complicated here, and you can easily eliminate such a malfunction.
Date: 16.09.2015 // 0 Comments
Continuing the topic of fixing fixtures, many will find it useful to know not only how to check a fluorescent lamp, but also how to check the ballast of a fluorescent lamp. For a quick check, a minimum of devices are needed: a control light, a wire, a couple of paper clips, as well as a few minutes of free time.
First, you need to present a diagram of the electronic ballast of a fluorescent lamp and add a control lamp (indicated by red lines) to its design.
Most luminaire circuits are almost identical to each other, differing only in minor changes.
In general terms, before checking the electronic ballast for fluorescent lamps, you need to remove the tube, then short-circuit the leads of the filaments, and then connect a regular 220 V low power incandescent light bulb between them.
Attention! To avoid the failure of the electronic components of the ballast, it is not recommended to connect the circuit with no load to the network, i.e. without a bulb.
For simple lamps, it is very convenient to use a paper clip, it reliably closes the contacts going to the tube.
After all the manipulations, such a structure can be included in the network. The working ballast will be able to supply voltage to the light bulb, and as you can see from the photo, it will glow.
If the ballast was repaired with your own hands, and you need to check its performance, it is best to connect another light bulb in series with the lamp. In the event of errors made in the work, or a short circuit, this light will glow brightly, and the circuit components will not fail.
In this article I will tell you the common breakdowns of modern "ballasts" of fluorescent lamps, how to repair them, I will give analogs of radio components that can be used for repair. Because These lamps are still quite common in everyday life (for example, I use 5 such lamps every day), I think the topic is more than relevant.
If your fluorescent lamp stops shining, the first step is to replace the fluorescent "bulb" itself. It may have two malfunctions: failure of one of the channels (breakage of the heating coil) or the banal "aging" effect.
If in the dark on a switched on lamp there is a barely noticeable glow of the filaments, then, most likely, the breakdown of the electronic "ballast" consists in the breakdown of the capacitor connecting the filaments (see Fig. Item 2). Its capacity is 4.7n, working voltage is 1.2kV. It is better to replace it with the same one, only with an operating voltage of 2kV. In cheap ballasts, there are 400 or even 250V capacitors. They are the first to fail.
When the actions from the previous paragraph did not help, you need to start checking the radio components with the fuse in the diagram. It is often available, but I do not have it on the board (see Fig. Item 1).
The next thing to pay attention to is transistors (see fig. Item 1). They can fail due to power surges, for example, if there is a relay voltage stabilizer at home, or often you or your neighbors use welding. These replacement transistors can be found in power supply units for energy saving lamps. Because such lamps often fail due to bulb breakdowns, then the circuit and, accordingly, the transistors, remain working.
If there are no such lamas, then you can replace the transistors with analogs. Analogs of transistors 13001, 13003, 13005, 13007, 13009 are shown in the table below. The most popular replacements are analogs such as KT8164A and KT872A.
Sometimes you need to ring the rest of the radio components and replace them, if damaged are found. After each stage of repairing the ballast of fluorescent lamps, it is recommended to turn them on for the first time through a 40-watt incandescent lamp connected in series. By its glow, you can see the presence of a short circuit.
It is important to remember that modern electronic ballasts are impulse devices, which are strictly prohibited to be switched on without load (in our case, a fluorescent lamp), because this will lead to their failure.
Video (click to play).
If you have tried everything, but nothing has helped, or there is no desire to tinker with the ballast, then you can use a switching power supply from an energy-saving lamp. It is so small that it fits easily in some fluorescent lamp housings. In this case, the filaments of the fluorescent lamp are connected to the contacts on the board, where the contacts of the bulb of the energy-saving lamp were connected. The wattage of the power supply should roughly match the wattage of the lamp. Personally, I have a 36W fluorescent lamp powered by a power supply from a 32W lamp.
