A motorized device for controlling curtains means a significant increase in indoor comfort. In addition to the convenience of manipulating curtains, such an electric drive guarantees the highest degree of safety of the curtain complex. This is explained by the fact that the electric drive forces are applied to curtains, runners and guide profiles in the most natural direction - along the line of movement. Such a natural and rational application of effort guarantees the least wear on all components and the same minimum risk of their breakage, especially the runners and hooks.
Do-it-yourself electric drive for curtains - the main components of such a device are covered with a simple screen.
Due to the fact that the drive device requires the placement of a control cable - a cord - transmitting force to the runners, such electrically controlled curtains can be made when used ceiling cornices. The control cord can be hidden in one of the cavities of the cornice profile, specially designed for such constructive solution. It is precisely this profile, designed for curtains with control, that is chosen by House master to implement your plans.
Some home craftsmen also install an electric drive for curtains placed on a regular aluminum or even plastic cornice ceiling profile. The fact is that a set of curtains, most often, is installed near a window and in such a place it is quite possible to hide the visible control cord with the help of inconspicuous additional decor.
DIY electric drive
The experience of many craftsmen has shown that the most effective results are independent device electrical control curtains can be achieved using a ready-made window lift drive unit for any car. Here are the main technical qualities of this automotive unit that explain this decision:
- The operation of a car window lifter fully corresponds to the nature of the operation of the curtains - it is a reciprocating movement. Accordingly, the design of the window lift drive unit corresponds to the idea of automating the control of curtains
- The forces developed by the automobile electric drive are sufficient to control curtains of medium and even heavy weight
- The device of such a drive can be improved by the automatic stop used on the car.
The most important thing is that the curtain control cord can be arranged in exactly the same way as the control cable in a car drive. The master is required to solve all related problems, first of all, securely fastening the drive unit to the wall and creating a functional transmission that requires the installation of blocks. Such blocks can also be selected from the complex automotive industry.
It is important that the master can competently overcome the main drawback of such an automotive system - power from a source direct current 12 volts. For the corresponding transforming device, it is best to provide a ventilated niche near the consumer motor, where you can place the necessary relays and a fuse assembly that protects this circuit.
Every year the problem self-made electric drive for curtains is becoming less and less acute. Many manufacturers of electromechanical equipment offer new and new models of electric drives for curtains. In our time electric drive for roller blinds with your own hands increasingly means good choice manufacturer and supplier of such a device.
The do-it-yourself tradition, fashionable in the West, is supported by many manufacturers of electric drives that are designed for amateur installation and connection. The buyer only needs to select and . Once these structures are in place, the most suitable remote control propulsion system can be selected to go with them.
Drive equipment is available for all types of curtains. Settings for sliding systems, which is not much different from the average level, miniature and quiet models are more expensive - a skilled craftsman can make a choice with high accuracy.
In this article I will talk about the design automatic drive curtains installed on my balcony. There we grow flowers that are harmed by direct sunlight. In addition, in the summer, if the balcony windows are closed, with direct sunlight the air on the balcony quickly overheats. However, when there is no direct light, it is advisable to open the curtains - the shadow also does not contribute to the growth of flowers. Therefore, to maintain acceptable illumination on the balcony, I automated the operation of the curtains.
Mechanics
The curtains were originally already on the balcony. There are two of them, both suspended on a metal cable stretched under the ceiling from one wall of the balcony to the other. It is clear that you need to move both curtains at once, and due to the friction of the curtains on the cable (it is quite rough), the required force must be quite large. In addition, sometimes there may be obstacles in the path of the curtains, for example, a slightly open balcony window, which further increases the strength requirements.
Thus, the drive must be sufficiently powerful and reliable - on the balcony it often happens high humidity, quite a large temperature difference between winter and summer is possible. Therefore, I based the drive on a car window lift drive. It has sufficient power, is capable of producing high torque (it has a built-in worm gear) and is very reliable.
The mechanical diagram of the drive is shown below:
More details about the design. A plastic roller with a groove is attached to the window lift drive shaft (on the left in the diagram), on which a turn of rope is wound. The drive is mounted on one of the walls of the balcony. A similar roller is attached to the opposite wall, through which a rope is also thrown.
After this, the rope is tensioned so that the friction of the rope on the drive roller is enough to move the curtains. The opposite ends of each curtain are attached to a rope so that when the motor rotates, the curtain moves or moves apart.
To test the operation of the drive, I made a smaller model of it. The window lift drive and the independent roller were mounted on a board, a rope was pulled between them, after which it was possible to check the operation of the electronics and measure the force developed by the drive.
Photo of the drive itself on the layout:
As can be seen from the photo, a fairly large thin plate is attached to the window lift drive (I used textolite). Attached to it metal corner with two holes through which a rope is passed. It is needed so that the turn of the rope on the roller does not get tangled; for this purpose, the holes in the corner are made at different heights relative to the plate.
To the right of the corner are limit switches needed to stop the curtains in their extreme positions. In order to indicate these positions, two plastic tubes are put on the rope (only one of them is visible in the photo next to the bottom switch). The tubes are arranged so that when the curtain reaches its extreme position, one of them presses the switch, and for reliable pressing, it is attached next to each of the switches. metal plate, which presses the tube to the switch.
Three metal racks attached to the plate are needed to secure the drive cover.
Both rope rollers are made from furniture wheels. Using a drill and a file, you need to make a groove in each of them; two turns of rope should fit in the groove of the drive roller. The drive roller is attached to the shaft by tension, and the hole in it had to be bored out to a square one, since the drive shaft is square.
The drive is attached to the balcony wall using suitable furniture corners (one of them is visible in the photo on the left). There are enough mounting holes in the window lift drive, so there are no problems with fastening.
View of the drive already attached to the wall and covered with a lid:
In order to tension the rope, a special screw with a nut is used, to which the ends of the rope are attached:
The end of one of the curtains is also attached to it.
Electronics
All my electronics are divided into two parts - power and control. The main task of the power section is to provide power to the drive motor. The power window drive can draw very high current. To reduce this current, I reduced the drive supply voltage to 5 volts, but even so, the maximum current consumed by the motor can reach up to 3A. To provide such a current, I used a printer power supply capable of delivering a voltage of about 30V and a current of up to 0.7A, as well as a DC-DC converter of up to 5V. By lowering the voltage, DC-DC is quite capable of delivering the required current.
Motor power control is carried out using a powerful relay designed to change the polarity of the signal, and a MOSFET that controls the voltage supply to the motor. Thanks to the use of MOSFETs, it is possible to control the rotation speed of the motor, but this feature is not currently used.
Also installed on the power section are stabilizers designed to power the control electronics and the engine power control circuit. The stabilizers are powered from a lower voltage circuit of the power supply, the voltage there does not exceed 12V.
Power circuit diagram
The control electronics are represented by the STM8S microcontroller. The controller performs quite a lot of functions - measuring illumination, making a decision about starting the drive, monitoring the position of the curtains using limit switches, controlling the power supply of the drive, controlling the drive in manual mode- according to remote control commands. In addition, a radio module based on NRF24L01 and a 1-Wire bus are connected to the controller, through which three temperature sensors are connected. Using a radio module, you can control the drive and read temperature values in different points balcony and on the street, however, at the moment the second radio module is connected only to breadboard, so I won’t consider this functionality further.
The printer power supply used has an input for switching it to Stand-by state. I also use it, which reduces the energy consumption of the structure. The program takes into account that the power supply switches to operating mode with a certain delay, and after 30 seconds of inactivity of the drive, the power supply again switches to Stand-by mode.
Indication of drive operation using a three-color LED (only blue and red diodes are used). Blue lights up when voltage is applied to the motor, red starts flashing periodically if there are errors in the drive operation. The number of flashes allows you to determine the error number.
For sound alarm For some events (for example, when a command is given to close curtains that are already closed), the drive motor itself is used. A PWM signal with a small duty cycle is supplied to it, as a result of which the engine beeps quite loudly.
Control circuit diagram
A photoresistor attached to the window with a suction cup is used as a light sensor. Since the suction cup may fall off the window, there is a small button next to the photoresistor. While the suction cup is held on the window, the button is pressed against the window. If the suction cup falls off, the automatic operation of the drive stops and the red diode begins to flash. If the sensor is not connected to the connector, this is also detected by the controller.
Type of light sensor:
Since the illumination of the sensor can change sharply - due to various flashes on the street, partly cloudy weather - the data from the sensor has to be filtered. I have implemented the following processing algorithm: data from the sensor is digitized at a frequency of 10 Hz and written to an array. Once a second, the value of this array is averaged (primarily this is needed to filter out noise and flashes). Next, the resulting values are added to another array of 600 elements; after reaching the end of the array, recording begins from the beginning. Also, this array is analyzed every second - the controller calculates what percentage of the array elements is less than a certain threshold (with increasing illumination, the voltage at the output of the photosensor drops). If the values of more than 66% of the elements are less than a given threshold, then it is considered that the illumination is high enough and the curtains can be closed. In this way, periodic changes in illumination are filtered. At the same time, a limitation is also imposed on the operating frequency of the drive - in automatic mode, the motor turns on no more than once every ten minutes.
As I mentioned above, it is possible to control the curtains from the remote control. Using the remote control, you can fully open and close the curtains, partially open them, and start the drive based on the instantaneous illumination value. When controlled from the remote control, there are no restrictions on the operating frequency of the drive.
It is also possible to programmatically reboot the controller.
When moving the curtains, the controller monitors the state of the limit switches. If, after starting to move, the corresponding switch does not operate within 20 seconds, the engine stops working. To continue operation of the drive after eliminating the malfunction, you just need to reboot the controller.
All electronics are installed in a standard plastic case:
One of the switches is needed to switch the electronics to automatic operation mode, the second allows you to completely turn off the power to the motor.
Using 3.5mm Jack sockets, a light sensor, TSOP for receiving data from the remote control, and external temperature sensors are connected to the device.
The LED is covered with a white cap so it can be seen from any angle.
View of the assembled and installed electronics unit:
Video of the drive operation (control from the remote control):
Electric drive for blinds
(video at the end of the review)
As part of the implementation of the “smart home” idea, I had a long-standing desire to purchase electric blinds, or as they are sometimes called, “motorized blinds.” Plastic windows They were installed a long time ago, the blinds (regular, aluminum) were purchased a long time ago and perform their function perfectly. But I set out to equip them with an electric drive. And having studied the offers on the market, the prices increased a little! Some companies offer electric blinds for one window at a price of 30 thousand rubles! I have a three-section window. It turns out the price will be 90 thousand rubles! This is not even funny anymore... Moreover, I will definitely have to change the blinds to the “correct” model, which is suitable for branded electric drives. In general, all this did not suit me, to put it mildly. I couldn't find any good options on EBay either. Maybe I was looking in the wrong place?... Whatever wasn’t expensive and could be screwed to your existing blinds. After thinking about it in my spare time, I came to the conclusion that there is nothing complicated here, and you can do everything yourself.
And so, on the one hand, the topic is for those who have a great desire to get electric blinds, and on the other hand, they have the ability to work creatively with their hands
What we have?
Classic aluminum blinds. I have a three-leaf window, which means there are 3 blinds.
Like most similar blinds, the controls here are implemented in a simple manner. classic scheme: pull the rope - lift the blinds up, twist the plastic stick (in one direction or the other) - the blinds open or close by turning.
There are actually variations in needs here. An electric drive can be used to raise the blinds upward. Or for turning the doors (opening and closing). You can, of course, do both at the same time. Since in everyday life I most often use the mechanism for turning the “blades” when opening or closing a window, this is exactly what it was decided to do with an electric drive.
I want to say right away that implementing the idea of homemade motorized blinds does not limit your imagination. You can control it from a remote control, control it using an external light sensor, a motion sensor, you can do it automatically using a timer (for example, the blinds close in the evening and open in the morning). Moreover, all this can be done practically at a simple, everyday level. You can use a regular timer that controls the outlet. Regarding remote control from the remote control, you can also use numerous devices plugged between the outlet and the consumer, controlled remotely. A sea of these are now sold and they are not at all expensive. All this will be connected simply.
I personally don't need wireless remote control DU. A wired remote control standing on the table near the computer will triple my needs. I don’t feel the need for a timer either (at least not yet). So in my review I will describe the implementation of “motorized blinds” for myself. Although there can of course be a lot of automation options here. And not at all for the crazy money that all this now costs on the market.
So:
The main idea was to create a mechanism in which the blinds themselves and their structure would not be damaged. I somehow don’t like spoiling good things, so I was guided by the principle of making as few changes as possible to the blinds. I did this with an eye to the fact that it would be possible to disassemble everything and return the blinds to their original state.
The main center for the implementation of the idea is the motors. After doing a little research on EBay, I found all sorts of "movers" for sale to suit every taste. The main thing here is to buy a motor with a gearbox. This will allow, on the one hand, to select (upon purchase) any required shaft rotation speed, and on the other hand, the rotation force will be sufficient to rotate the blind handle.
Having estimated how many revolutions the blinds handle makes to open or close them, I settled on a motor with a shaft rotation speed of 15 revolutions per minute (in general, it could have been faster). Supply voltage 12 volts. Finding such motors on EBay is very easy. There are options with at different speeds rotation. Everyone will be able to choose what they need.
In the EBay search we write: Motor 12v 15 rpm(rpm - shaft rotation speed).
3 motors costing $13 apiece were purchased and soon arrived to me from China.
It is very important that the motors are reversible. This means that when the polarity changes, the shaft can rotate in reverse side. Not all motors can do this. If you find one like in my photo, you can safely take it. They come in 15, 20, 30, 50 rpm, etc.. and look the same.
A day of work and you're done! HOORAY!
You can sit back in your chair, drink coffee, whoever smokes, smoke
Video of how it all works. The cable length of the remote control is 10 meters. The video can be viewed in HD quality directly on YouTube:
Thank you for your attention to my review.
I will answer your questions.
If you have other ideas/implementation options for electric drives for classic blinds, write, it will be interesting.
In my personal opinion, the greatest interest is in designs that allow you to motorize any existing blinds, rather than buying some special models for a specific drive.
Let's consider the operating principle of the automation system circuit. Let's say the curtain is in the open state and the Limit Switch GC2 is in the on state. If you press the KH2 "" button, then nothing will happen, since the button is shorted to ground by the closed contacts of the reed switch GC2. If you briefly press the KH1 “↓” button, the transistor VT1 will open with the current flowing through the resistor R1. Relay P1 will operate. Using contacts P1.1, the relay will supply power to the electric motor and the curtain will begin to lower. At the same time, contacts P1.2 will break the power supply circuit of the KH1 button and block the operation of the KH2 button. When the curtain is lowered to the lower position, sensor GC1 will operate and turn off relay P1 - the device will stop in standby mode. The device operates in a similar mode and when moving upward when contacts P2.1 are triggered, the motor will rotate in the other direction. If you need to stop the curtain in any intermediate position, then pressing the KH3 “Stop” button will de-energize the relay, respectively, turning off the engine and setting the device to standby mode.
The circuit is powered by a bridge rectifier that rectifies an alternating voltage of 18 Volts from the secondary winding of transformer T1. A 0.5 A fuse is installed in the mains voltage supply circuit. The electric motor was powered by a separate stabilizer on a KREN5 microcircuit mounted on a powerful radiator. Subsequently, a 24-volt electric motor from the printer was installed and the circuit took the form shown. It turns out that all motors in electric screwdrivers, screwdrivers, toys and printers are unified in size and mounting.
Device details
Silicon transistors of medium or high power n-p-n structures. Relay series RES9 passport RS4524200. VD ordinary rectifier diodes are required to be installed. Any buttons to open. Capacitor in the filter with a capacity of 500-100vra for 50 volts. Any bridge rectifier for a current of 3-4A.
The installation was carried out by hand using a hinged method on the relay contacts; the relays themselves are installed on a textolite board. The controls, transformer and electronics are housed in a suitable housing. A DB9 type socket is installed on the case for connecting a connector with a cable for supplying signals from sensors and powering the motor motor. See photo.
The homemade curtain has been working reliably for three years now. The automation circuit can be successfully used to control other devices, for example, electrified lifts Garage Doors various designs it is permissible to control according to this scheme. In the future, it is planned to make automatic control of the Roman blind on the Arduino board with the implementation remote control via IR remote control and automatic operation from the light sensor. An example of how the curtain works in its current state is shown in the video
One day, after a hard day at work, I came home and realized that I wanted to relax, and not walk around and close the curtains. I would like to see them closed in the evening and open in the morning, without dancing in front of the window. Googling different solutions, it was decided to do everything myself.
By popular demand, I am posting all my work on converting regular roller blinds into automated ones with remote control. Be careful, there are a lot of photos!
First, about roller blinds:
- Pros: roller blinds visually expand the space, are beautiful and inexpensive. Very easy installation. Each window can be controlled separately. Frees up space on the windowsill.
- Difficulties: manually opening 5 windows already takes a long time. The mechanism itself prevents the corner window from opening completely (example: the mechanism at the top balcony door rests against the wall and does not allow the passage to open completely). Because of this, it is necessary to hang curtains with outside window. The price of even Chinese motorized curtains starts at 2,000 rubles, multiply by 5 and immediately think about how to do everything with improvised means.
A little about the tasks:
Must be added to regular roller blinds made of hardware store remote control and connect to smart home on the openSource Home Assistant platform. And you still need to maintain the usual control of the rope.
Choice of motors:
If everything is automated, then speed does not matter, so motors with gearboxes can be used. Brushed motors are cheap, but not the most reliable thing for daily use. Servos also have commutator motors and are not stable during constant rotation. Stepper motors look like an excellent option. They are silent, you can control the position, they cost pennies. As a result, a set of 5 28BYJ-48 engines with a ULN2003 driver cost me $10
About the 28BYJ-48 engine:
There were questions about the power of this engine. Fears that he would be weak were not justified. Or rather, if you use a full-step mode, then the motor is very frail, if you use a half-step mode, then the shaft is narrower with bare hands can't stop. For those who don’t have enough power, there are many articles on the Internet on how to raise the voltage, turn it into bipolar and other improvements.
About sensors:
Since we have left manual control, and we don’t want to waste the engine, then curtain position sensors are needed. At a minimum, one sensor is required at one end, but two are better. You can use any end switch, optical one, etc., but I personally chose the reed switch because... gluing a neodymium magnet on the other side is very simple and should work stably and durable. I chose the reed switches themselves for aesthetics already in the housing. Plus, it provided for setting the distance from the shaft. The height can be adjusted with spacers.
About the mounting design:
The task was to design the case as simple as possible for manufacturing on a 3D printer with minimal modifications. Modeled in Fusion 360. The complete mount clings to the top of the window, but such a design on an FDM printer would be difficult to make with the required strength requirements, so a design with one screw for adjustment was invented.
In total, we got three parts for 3D printing. Link to download 3D models.
Main part for the motor, control board on ULM2003, mounting of reed switches, motors, line for stabilizing curtains, and adjusting screw.
A lid to cover all this mess. A clamp or in other words a hook.
The design of the curtains itself contains several springs, which work as a brake if you pull the curtains (the spring is tightened) or release it if you twist the rope.
When assembling, you need to make one modification: use wire cutters to break the rim that covers the rope, because... Now we have our own fixed rim that prevents the rope from falling out.
Control:
The stepper motor will be controlled by a NodeMCU on an ESP8266. It was chosen because it is cheap, has a backup Wi-Fi channel, and is quite easy to write the necessary scripts on. If you need more than two curtains or additional sensors, then the microcontroller legs are no longer enough, you can look towards the ESP32. (esp32 is not shown in the photo, because it is in the junction box)
Software part:
The development environment can be any. ESP32 can be programmed via Arduino IDE. But I chose Visual Studio Code for myself because of its speed, modularity and freeness. In this environment, you can develop for almost any platform (not just hardware). You can even connect IAR ARM. (But that's a completely different topic)
The program's task is simple:
Connect via Wi-fi
Connect to MQTT broker
Subscribe to topic
Control the speed of two motors
Monitor the condition of the limit sensors
Send current steps to the broker
Sources can be taken
