A problem often arises - we bought three - five (or more) arm chandeliers, but I would like to be able to turn on two or three lamps separately and all together. To do this, you need to have three wires stretched to the chandelier and then everything is simple - we control the chandelier using. But if there are two wires going to the chandelier, then it’s more complicated...
How to control a chandelier using two wires? The simplest solution is to install a diode and turn on the chandelier through the diode and directly, in the first case the chandelier will shine at full intensity, but the flickering of the chandelier lamps will be slightly noticeable. And in this case it will not be possible to use it.
There is also a more complex diode circuit that allows you to control two groups of lamps via two wires. The diagram is shown in the figure above. Unfortunately, this scheme has the same disadvantages.
This scheme works as follows: When you press the S1 key of a two-key switch, the lamp (group of lamps) L1 turns on, current flows through diodes D1 and D3, L2 does not turn on, because diode D2 is turned on in the opposite direction with respect to D3. Accordingly, when you press the S2 key, lamp L2 turns on.
Diodes are selected based on the power of the lamps. For example, a D226 diode will support a lamp (group of lamps) with a power of up to 60 W. Diodes D245, D246 can withstand power up to 2000 W. The reverse voltage of the diodes must be at least 300 V. Diodes D1, D2 are located in the decorative glass of the chandelier near the ceiling, and diodes D3, D4 are located in the switch housing.
Now we will look at a scheme that does not have the disadvantages of the previous one.
The diagram shows:
When you press the switch key S1, the first group of chandelier lamps L1 lights up. At the same time, voltage is applied to transformer T1, which lowers the voltage to approximately 15V, diode bridge D1-D4 rectifies the voltage. Relay K1 is turned on through normally closed contacts K2.1. Relay K1 switches capacitor C1 to the rectifier with contacts K1.1, the capacitor is charged.
In order to turn on the second group of lamps L2 (in addition to the first), you need to open and close the contacts of switch S1 again. In this case, relay K1 will be de-energized (when S1 opens) and contacts K1.1 will connect the charged capacitor C1 to the winding of relay K2, relay K2 will operate and self-block through its contacts K2.1. In this case, the relay will connect L2 to the network with contacts K2.2.
The time it takes to switch the contacts of switch S1 is determined by the capacitance of capacitor C1; with the indicated capacitance, this time will be at least 1 second.
L1, L2 - lamps in a chandelier, they can be of any power (the maximum is indicated in the chandelier's passport), it can be either one lamp or several connected in parallel. Lamps can be any - both ordinary and...
S1 is a regular single-key switch.
T1 - step-down transformer 220/15 V, with a power of at least 2 W. You can make the transformer yourself - on a Sh12x12 magnetic core, the primary winding is wound with PEV-1 wire, 0.08 mm - 6600 turns, on a cardboard frame, the secondary winding is wound with PEV-1 wire, 0.15 mm - 450 turns.
Diodes D1-D4 besides those indicated can be any, with a current of at least 400 mA and a reverse voltage of at least 25V.
Diode D5 must be designed for a current of at least 300 mA and a reverse voltage of at least 25V.
Relays, in addition to those indicated, can be used brand RES-22, pass. RF4.500.163 (or RF4.500.131).
Capacitor C1 - any electrolytic capacitance of at least 500 μF and with an operating voltage of at least 25V. A capacitor can be made up of several, as described.
All the details of the device can be placed on a board with dimensions of approximately 60x80 mm and this board can be placed in a decorative glass of a chandelier near the ceiling.
Be careful when installing the board, do not forget to turn off the power to the chandelier.
Write your wishes in the comments, the article can be changed or supplemented in accordance with them.
Chapter: House and ApartmentIn modern houses, as a rule, 3 wires are connected to the chandelier. 1 - neutral and 2 control, current. And the switch has 2 keys. With its help, you can control the chandelier lamps separately. For example, 2 lamps, 3 lamps and switching on 5 lamps together at once.
But in old houses the wiring is usually only two-wire and replacing it with multi-wire is quite problematic. The wire is often carried out in the voids of concrete floor slabs. And replacing it or laying a parallel one can only be done during major repairs.
With the cost of electricity constantly rising, the possibility of saving it is beginning to become a prominent item in the home budget. Meanwhile, those whose chandelier is connected via 2 wires are deprived of the ability to control their chandelier. Either it is turned off completely, or it is on full blast.
But the problem can be solved.
The easiest way is to buy (or make your own) a thyristor dimmer. They are also called dimmers. They are produced in abundance, and in a unified case, and the usual standard switch is simply replaced with such a regulator. But this method has several significant drawbacks. Firstly, such a regulator is still quite expensive - several hundred rubles. It will take more than one year for it to pay off. Secondly, cheap regulators create electrical interference and can degrade television and radio reception, as well as the operation of cordless phones. Thirdly, the adjustable power of such switches is usually very limited (300-500 watts). High power can damage them. And fourthly, the so-called regulators cannot work properly with such regulators. energy-saving lamps . This occurs due to the peculiarities of the way the electronic circuit is regulated.
More expensive dimmers may have touch controls, and even remote control using an IR remote control.
The second way to limit the power of lamps in a chandelier is to sequentially connect a powerful diode to the lamp control wire. The polarity of the diode does not matter. In this case, one switch key connects the chandelier to the phase through a diode, and the second - directly. (see diagram). If a diode is included in the circuit, then it “cuts off” one half-wave of the current and the lamps burn at full intensity. Accordingly, they consume approximately 2 times less energy. Due to the high inertia of the lamp filaments, flickering is unnoticeable. With this method, energy-saving lamps also do not work. In addition, at high power, the diode should be installed on a small radiator.
The third method is to include a quenching capacitor (capacitors) in the circuit as reactance. Since the capacitance of the capacitors can be changed (selected), it is also possible to select the desired glow levels of the chandelier lamps. For example, using a 3-key switch and 2 capacitors, you can get 4 levels of lamp illumination. (see diagram). Off - level 1 (On 1) - level 2 (On 2) - level 3 (On1 + On 2) - level 4 (On3). Capacitors do not heat up during operation. Their only drawback is their large dimensions for placement in the wall. You also need to select capacitors for the specific power of the lamps used. Don’t forget, the operating voltage of the capacitors must be at least 350-400 volts.
The fourth method does not have any disadvantages, since it uses direct switching on of the lamps without any additional elements in the network. In this case, the switch is simply located... on the chandelier! There are “ceiling” switches on sale that are literally miniature in size (1 x 1 cm) and placing it discreetly in a chandelier will not be difficult for a home craftsman. Or mount it next to the chandelier. The chandelier lamps are connected through this switch (see diagram). In this case, the main switch, as usual, controls the general turning on and off of the light “in general”. But the operating mode of the chandelier is set by the position of the built-in switch. You can, of course, consider a small cord hanging from a chandelier as an aesthetic flaw. But you can decorate it accordingly, in the style of the overall design of the room. Or make it completely invisible and short, with a loop or ring at the end. And turn it on and off using a small sticker with a hook on the end. On ordinary weekdays, switch the chandelier to economy mode, and on “holidays” and during “guests,” switch it to ceremonial light mode.
By the way, if you decide to use a remote-controlled lighting regulator (dimmer), it is not necessary to install it instead of a switch. It can also be mounted directly in the chandelier or next to it. Those. directly on the ceiling.
Konstantin Timoshenko
When dealing with repairs and all sorts of finishing and alterations, not every craftsman is able to provide for all the nuances and “little things.” And renovation and finishing work does not always include a complex of major renovations.
This happens very often with light. More precisely - s. For example: they forgot to run an additional wire for the lighting of the living room, or: they changed the wallpaper in the bedroom, but did not scratch the walls so as not to “spread dirt”, but there is no “evening” lighting for the room at all! There are many similar situations, and the modern idea of comfort is already inextricably linked with the wide possibilities of lighting design, with various lighting options. So let's think, because there are no hopeless situations!
Let's start with the most common case. In old apartments, only two wires are connected to the central chandelier, that is, even simple lighting in “two modes” cannot be done. Hammer the ceiling? Hang several sconces on the walls? Not necessary. There are many different “schemes” for controlling a chandelier over two wires - very simple, of medium complexity of implementation and quite serious electronic devices. We will look at the simplest and easiest to repeat switching circuit.
The very principle of “two-position” lighting is very simple, it is enough to reduce the current on the lamps of a lamp or chandelier, and by connecting a diode of sufficient power to the circuit, it will not be difficult to implement two lighting modes.
Each new press of the switch activates a new pair or group of lamps. To reset the pulses from the counter, it is enough to pause for a third of a minute.
Shift register in control system
The principle is already contained in the name itself. The impulse, hitting the starting point C, is transmitted further along the chain to D and 1.
The incandescent lamp circuit is connected and operates on the same principle as in the example with a meter.
To search for breaks in a faulty electrical network, special ones are used. As an alternative method, this can be done using a radio or smartphone.
Thyristor control system
Rectifier VD6-VD9 powers the entire control circuit. When the switch is turned to the “On” position, the first lamp in the EL3 circuit lights up.
Next, the capacitors charge and accumulate the high and low signal so that DD1 keeps the transistor and thyristor off. When the switch is turned to the "Off" position, the capacitor is recharged.
Microcontrolling a chandelier
The microprocessor is equipped with software. Thanks to this, the operating principle can be unique. After all, such a scheme may have additional built-in functionality in addition to conventional lighting. Nevertheless, the same scheme as in previous cases is taken as a basis.
The connection and control diagrams for the chandelier do not have such significant differences.
Even the electronic system remains true to the original principle.
But what really doesn’t add up is the quality and durability.
21-11-2013
Julia Truchsess
Electronic Design
The circuit solves the problem of information exchange via a cable in which there are no free wires left. An amplitude-shift keyed carrier signal can be transmitted over low-voltage power lines.
Sometimes it becomes necessary to organize data exchange when there are no more unused conductors left in the device cable for a dedicated communication line. Typically, this problem is solved using a high-frequency carrier, modulated by data and transmitted along power lines, in particular, through home electrical wires.
Searches on the Internet showed that, despite the relevance of this problem for many developers, no one offers simple, cheap and reliable solutions for low-voltage systems. Below is the result of an attempt to fill this gap. Please note that without special circuit safety precautions, this circuit is not suitable for high voltage applications.
The device, which requires only a handful of discrete components and a couple of chips, can reliably transmit and receive data at speeds of up to 32 kbps on a carrier frequency of 2.6 MHz. This speed could likely be increased many times over by using a higher carrier frequency and changing component ratings accordingly. The circuit can operate on a cable with a capacitance of up to 10 nF and has a low level of electromagnetic radiation. It transmits data in a standard serial asynchronous format compatible with UART, but nothing prevents developers from using Manchester encoding or other protocols.
For simplicity, carrier amplitude keying is used and no circuit solutions are provided to suppress intrinsic noise, other than a good signal-to-noise ratio. If desired, developers can implement software error detection and correction.
A PIC microcontroller with a set of peripherals is ideal for our circuit. In particular, its PWM module or programmable timer will be used to generate square-wave carrier signal pulses, as well as a high-speed comparator with rail-to-rail inputs (Figure 1). Of course, if you have the appropriate peripheral devices, you can use any other microcontroller.
The diagram shows two transceivers. Transceiver 1 (left) is the "remote" node receiving power from the "base" Transceiver 2 (right). Inductors L1 and L2 isolate the high-frequency carrier from the low-impedance power rail.
Several nodes can be connected into a multipoint bus if each node is separated from the power line by decoupling inductance. Small surface-mount inductors can be used, but their operating current must provide power to the load with some margin.
The transmitting part of the transceiver is made on a single-channel three-stable U2 bus driver of the TinyLogic () family. The driver outputs are connected to the bus through elements R1 and C1. Resistor R1 provides some filtering to reduce the level of electromagnetic radiation generated by the steep edges of the rectangular carrier.
The receiver connection point is formed by elements C2, D2 and D3, followed by two peak detectors. The first detector, with a time constant equal to approximately one-third the duration of the information bit, demodulates the carrier to restore data synchronization. The second, with a time constant approximately 50 times the duration of the data bit, adaptively restores the carrier level. Resistors R3 and R5 divide this level to approximately two-thirds the carrier amplitude.
The outputs of both detectors are connected to the inputs of the internal analog comparator of the microcontroller, which finally generates rectangular data signals, which are then sent to the UART through an external circuit. Resistor R4 slightly biases the non-inverting input of the comparator upward to provide a predictable log level in the absence of exchange. 1".
It should be noted that the input and output of the transceiver are always connected together, so care must be taken that the program ignores signals received from its own transmitter.
In Figure 2, the yellow waveform shows the raw digital data sent by the remote transceiver to the transmit UART port. Blue shows the result of carrier modulation as seen on the power rail. The pink color indicates the demodulated and reconstructed signal coming from the comparator output to the RXD UART input.
Figure 3 illustrates the details of the demodulation and data recovery process. The input amplitude-keyed signal (blue), after processing by two detectors, is fed to the inverting and non-inverting inputs of the comparator (yellow and green, respectively). The data recovered from the comparator output is shown in pink.
Julia Truchsess has had a successful career creating a number of electronic toys, including MicroJammers, Rhythm Rods and Singing Bouncy Baby, many of which have sold millions of copies. In the late 1990s, Julia came up with the idea of digital photo frames, the production of which was soon organized under the Digi-Frame brand. After the debut of the Digi-Frame, many large companies began to produce similar products, but, according to observers, the Digi-Frame was “the Rolls-Royce of frames.”
Julia runs Pragmatic Designs (www.pragmaticdesigns.com), founded in 1986.
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When dealing with repairs and all sorts of finishing and alterations, not every craftsman is able to provide for all the nuances and “little things.” And renovation and finishing work does not always include a complex of major renovations.
This happens very often with light. More precisely - s. For example: they forgot to run an additional wire for the lighting of the living room, or: they changed the wallpaper in the bedroom, but did not scratch the walls so as not to “spread dirt”, but there is no “evening” lighting for the room at all! There are many similar situations, and the modern idea of comfort is already inextricably linked with the wide possibilities of lighting design, with various lighting options. So let's think, because there are no hopeless situations!
Let's start with the most common case. In old apartments, only two wires are connected to the central chandelier, that is, even simple lighting in “two modes” cannot be done. Hammer the ceiling? Hang several sconces on the walls? Not necessary. There are many different “schemes” for controlling a chandelier via two wires - very simple, of medium complexity of implementation and quite serious electronic devices. We will look at the simplest and easiest to repeat switching circuit.
The very principle of “two-position” lighting is very simple, it is enough to reduce the current on the lamps of a lamp or chandelier, and by connecting a diode of sufficient power to the circuit, it will not be difficult to implement two lighting modes.
This device differs from similar ones in purpose (for example, [L]) by the possibility of simultaneous transmission of several commands in any combination and the convenience of monitoring the transmitted information (by the position of the knobs or switch buttons on the transmitter remote control). In addition, the transmitter does not require its own power source - it powered via the same communication line.The system remains operational when the supply voltage changes from 9 to 5 V, and when using K561 series microcircuits - from 12 to 5 V.
The principle of operation of the device is as follows. The required commands are transmitted by setting the control panel switches to the appropriate position. The transmitter cyclically polls the status of the remote control contactor at a clock frequency. A sequence of command pulses (closed contacts correspond to a short pulse, open contacts correspond to a long pulse) is transmitted via a communication line to the receiver. The receiving device processes the received information and generates a signal to turn on the corresponding loads.
Each new press of the switch activates a new pair or group of lamps. To reset the pulses from the counter, it is enough to pause for a third of a minute.
Shift register in control system
The principle is already contained in the name itself. The impulse, hitting the starting point C, is transmitted further along the chain to D and 1.
The incandescent lamp circuit is connected and operates on the same principle as in the example with a meter.
To search for breaks in a faulty electrical network, special ones are used. As an alternative method, this can be done using a radio or smartphone.
Thyristor control system
Rectifier VD6-VD9 powers the entire control circuit. When the switch is turned to the “On” position, the first lamp in the EL3 circuit lights up.
Next, the capacitors charge and accumulate the high and low signal so that DD1 keeps the transistor and thyristor off. When the switch is turned to the "Off" position, the capacitor is recharged.
Microcontrolling a chandelier
The microprocessor is equipped with software. Thanks to this, the operating principle can be unique. After all, such a scheme may have additional built-in functionality in addition to conventional lighting. Nevertheless, the same scheme as in previous cases is taken as a basis.
The connection and control diagrams for the chandelier do not have such significant differences.
Even the electronic system remains true to the original principle.
But what really doesn’t add up is the quality and durability.
One good electronics engineer said that if there is a relay in the circuit, then it needs to be improved. And one cannot but agree with this: the operating life of the relay contacts is only a few hundred, maybe thousands of times, while a transistor operating at a frequency of at least 1 KHz makes 1000 switchings every second.
Field-effect transistor circuit
This scheme was proposed in the magazine “Radio” No. 9, 2006. It is shown in Figure 1.
The operating algorithm of the circuit is the same as the previous two: with each short click of the switch, a new group of lamps is connected. Only in those schemes there is one group, but in this one there are two.
It is easy to see that the basis of the circuit is a two-digit counter, made on the K561TM2 microcircuit, containing 2 D-flip-flops in one housing. These flip-flops contain a regular two-digit binary counter, which can count according to the algorithm 00b, 01b, 10b, 11b, and again in the same order 00b, 01b, 10b, 11b... The letter “b” indicates that the numbers are indicated in the binary system Reckoning. The least significant digit in these numbers corresponds to the direct output of the trigger DD2.1, and the most significant one corresponds to the direct output of DD2.2. Each one in these numbers indicates that the corresponding transistor is open and the corresponding group of lamps is connected.
Thus, the following algorithm for turning on the lamps is obtained. Lamp EL1 lights up as soon as switch SA1 closes. When the switch is briefly clicked, the lamps will light up in the following combinations: EL1; (EL1 & EL2); (EL1 & EL3 & EL4); (EL1 & EL2 & EL3 & EL4).
In order to switch according to the specified algorithm, counting pulses should be supplied to input C of the low-order digit of the counter DD2.1 at the moment of each click of the SA1 switch.
Figure 1. Control circuit for a chandelier using field-effect transistors
Counter management
It is carried out in two impulses. The first of them is a counter reset pulse, and the second is a counting pulse that switches the lamps.
Counter reset pulse
When you turn on the device after a long shutdown (at least 15 seconds), it is completely discharged. When switch SA1 is closed, the pulsating voltage from the rectifier bridge VD2 with a frequency of 100 Hz through resistor R1 forms voltage pulses limited by the zener diode VD1 at 12V. With these pulses, the electrolytic capacitor C1 begins to charge through the decoupling diode VD4. At this moment, the differential circuit C3, R4 generates a high-level pulse at the R inputs of triggers DD2.1, DD2.2, and the counter is reset to state 00. Transistors VT1, VT2 are closed, so when the chandelier is first turned on, lamps EL2...EL4 do not light up. Only the EL lamp remains on, since it is turned on directly by the switch.
Formation of counting pulses
Through diode VD3, pulses generated by zener diode VD1 charge capacitor C2 and maintain it in a charged state. Therefore, the DD1.3 output is maintained at a low logic level.
When switch SA1 is briefly opened, the pulsating voltage from the rectifier stops. Therefore, capacitor C2 has time to discharge, which will take about 30ms, and a high logical level is set at the output of element DD1.3 - a voltage drop is formed from low to high level, or, as it is often called, the rising edge of the pulse. It is this rising edge that sets the DD2.1 trigger to a single state, preparing to turn on the lamp.
If you look closely at the image, you will notice that its clock input C begins with an inclined segment running from left - up - to the right. This segment indicates that the trigger at input C is triggered by the rising edge of the pulse.
Here is the time to remember about the electrolytic capacitor C1. Connected through the decoupling diode VD4, it can only be discharged through microcircuits DD1 and DD2, in other words, keep them in working condition for some time. The question is how long?
Typically, systems that operate by modulating infrared radiation or radio signals are now used to remotely control equipment or equipment. But in some cases, a wired remote control option may be more preferable. Here, in addition to the only drawback - wires, there are many advantages, such as the complete absence of interference, the ability to control not in direct line of sight (a two-wire line can also be laid along a labyrinth of concrete walls), and lack of dependence on a galvanic current source.
Despite the apparent variety of circuits, devices for transmitting several commands over a two-wire line can be of only two types: digital and analog. A digital device, in its most simply implemented form, is a TV remote control system in which the IR ray transmitter and photodetector are replaced by a two-wire line, or a digital radio control system for models in which a wired transmission line is used instead of a radio channel. An analog system will be based on changing some analog quantity, such as the frequency of a sine wave or the magnitude of a DC voltage.
From the point of view of a minimum of noise emissions and ease of implementation, it seems more acceptable to have a change in the DC voltage on a two-wire line by changing the resistance of the remote control. In this case, the remote control does not contain active elements at all and is extremely simple (buttons with resistors), and the receiving unit is also uncomplicated. One drawback is that stabilization of the supply voltage is required, but this is easily achievable.
One example of a two-wire remote control operating on this principle is the stationary control keyboards of most video players and some televisions. In them, the control panel is a board with buttons and constant resistors, which is connected by a two-wire line to a control microcontroller. Pressing each button corresponds to a certain level of constant voltage at the input of the microcontroller keyboard.
Figure 1 shows a similar diagram of a remote control for eight commands. It is based on a scale indicator circuit (L.1), with the difference that its input receives the voltage obtained using a divider on the resistors of the control panel.
An eight-level comparator is built on eight operational amplifiers A1.1-A2.4. The reference voltages are supplied to the inverse inputs of the operational amplifiers from a divider on resistors R9-R17. If you look at the diagram from below, the lowest reference voltage will be at input A2.4, and the highest at input A1.1. By changing the voltage at the direct inputs of the op-amp connected together, gradually, from the minimum value to the maximum, you can sequentially transfer all the op-amps to the log state. units at the output. Thus, the higher the voltage, the greater the number of op-amps will be in a single state. It is on this principle that the indicator from L.1 works.
But, in this case, it is required that when you press one button, the unit should be only on one of the device’s outputs, and not on the output line. An expression of the number of the pressed button in decimal code is required.
The decoder that converts the line of units into the decimal system is built on two microcircuits D1 and D2. Their XOR gates are included so that when any button is pressed, a 1 will only appear on one specific output of the device. For example, if you press the S3 button, logical ones will be at the outputs of operational amplifiers A1.3, A1.4, A2.1, A2.2, A2.3, A2.4. And the decoder converts this code so that one will be only at output 3 (output D1.3).
The device is controlled using a remote control consisting of buttons S1-S8 and resistors R1-R8. The remote control is connected to the device by a two-wire line, and together with resistor R18 it forms a voltage divider, which sets the voltage supplied to the direct inputs of all op-amps connected together.
