Unusual dynamic LED clock powered by a motor from a hard drive.
Device diagram:
Well, when all doubts are put aside, we can begin...
To make a propeller watch we will need:
* 2 sheets of fiberglass, one is double-sided (45*120mm), and the second is single-sided (35*60mm).
* Iron and Ferric Chloride (for etching boards).
* Motor from HDD drive.
* Soldering iron with a thin tip, mini-drill.
For watches:
* LED driver MBI5170CD(SOP16, 8 bit) - 4 pieces.
* Real time clock DS1307Z/ZN(SMD, SO8) - 1 piece.
* Microcontroller ATmega32-16AU (32K Flash, TQFP44, 16MH) - 1 piece.
* Quartz resonators 16MHz - 1 piece.
* Quartz resonators 32kHz - 1 piece.
* Ker. capacitor 100nF (0603 SMD) - 6 pieces.
* Ker. capacitor 22pF (0603 SMD) - 2 pieces.
* Ker. capacitor 10mF*10v (0603 SMD) - 2 pieces.
* Resistor 10kOm (0603 SMD) - 5 pieces.
* Resistor 200Om (0603 SMD) - 1 piece.
* Resistor 270Om (0603 SMD) - 1 piece.
* 2kOm resistor (0603 SMD) - 4 pieces.
* Clock battery and holder for it
* IR LED
* IR transistor
* LEDs (0850) 33 pieces (one of them (the last one) can be of a different color)
For the motor driver:
* TDA5140A motor driver - 1 piece.
* Linear stabilizer 78M05CDT - 1 piece.
* Capacitor 100 mF polar (0603 SMD) - 1 piece.
* Ker. capacitor 100 nF (0603 SMD) - 1 piece.
* Capacitor 10 mF polar (0603 SMD) - 2 pieces.
* Ker. capacitor 10 nF (0603 SMD) - 1 piece.
* Ker. capacitor 220 nF (0603 SMD) - 1 piece.
* 20 nF - 2 pieces.
* Resistor 10 kOm (0603 SMD) - 1 piece.
1) First we need to make 2 boards.
2) We are looking for an old unnecessary hard drive to remove the motor from it, in some hard drives the motor is not attached with bolts, but is pressed into the case, pay attention to this when choosing a hard drive, otherwise you will have to cut it out :)
Main functions
Below are the main functions of the watch:
Time and date display
Setting all parameters from the RC-5 type remote control
Time display in digital and dial modes without date and with date
Displaying five-minute divisions
Uses 5mm super bright LEDs
Creeping line with character generator.
A running line with a length of 128 characters is written to the EEPROM.
Demo mode. Cyclic switching between ticker, analogue and digital display.
Setting the time
Since all the electronics are on a rotating lever, the question arises: How to set the time? In many models, the time is set on the lever itself using special buttons. With this design, you will be able to see the set time only after the lever is activated. If the setting is incorrect, you will have to stop the lever again and again set the time blindly. In this watch, setting is done from the remote control. Setting the time in dial mode looks especially impressive.
Mechanics
Let's move on to the most difficult stage of watchmaking - mechanics. First, you need a fan from the computer's power supply. It is highly advisable to use a high-quality fan with ball bearings; this will significantly extend the life of your watch. As a rule, the rotation speed of computer fans is 3000 rpm or 50 revolutions per second. This rotation speed allows for a very stable image. But a lever rotating at such a speed creates a lot of noise. So I lowered the speed to an acceptable noise level.
Energy can be transferred from a stationary part to a rotating part in different ways. The most common is sliding contact. This method has many disadvantages - contact instability, noise, mechanical wear. The watch I made used a more elegant method. A transformer consisting of moving and stationary work. Its production is perhaps the most important stage in the manufacture of watches. First of all, you need to carefully disassemble the fan. To do this, you need to peel off the sticker from the back. And carefully pull out the retaining ring. After which you can remove the impeller and rotor. We no longer need the plastic impeller either. We remove it from the metal base and wind the secondary winding onto it. The winding contains about 150 turns of winding wire with a diameter of 0.3 mm. This is approximately 5 layers. Each layer was coated with silicone sealant (available on any construction market) and dried.
I highly recommend using wire in silk insulation - this will make it easier to fix the turns. A regular wire will slide off the metal base.
To attach the lever, several holes are drilled in the rotor.
Most of the plastic is removed from the stationary part of the fan, leaving only the bottom frame.
The gap between the primary and secondary windings should be minimal. In reality it turns out somewhere between 0.3 – 0.7 mm. To make the primary winding, it is necessary to make a mandrel. To do this, take any cylinder of a suitable size (I used an old capacitor) on which the required amount of paper is tightly wound until the desired diameter is reached. Next, about 100 turns of wire are wound around this mandrel, similar to the secondary winding. After the sealant has dried, the mandrel is carefully pulled out. The resulting wire ring is centered and fixed with sealant to the base of the fan. Thus we received a transformer for transmitting energy to the rotating parts.
Next you need to make a rotor position sensor. For this, any infrared LED and phototransistor are used. The LED is installed on a fixed base. Phototransistor on the rotating part at the same radius. Thus, the phototransistor would light up once per revolution. It is convenient to use a cut optocoupler.
Electronics
The watch electronics consists of two parts - rotating and stationary.
Fixed part
Schematic diagram of the fixed part
It is implemented on the pic16f628 microcontroller, which decodes commands from the IR receiver. This allows you to turn the clock rotor on and off. In the on mode, the microcontroller supplies a PWM signal to the gate of the transistor, which modulates the voltage in the primary winding of the transformer. You will have to select the PWM frequency yourself. For each transformer it has its own optimal value. In my version it had a value of about 7 KHz. The disadvantage of this is a slight whistling of the engine rotor. It is better if it is more than 16 kHz.
In off mode, the engine turns off. Then, after a few seconds, the duty cycle of the pulses in the primary winding decreases. In this mode, energy is needed only to keep the clock running.
To adjust the engine speed, an LM317 microcircuit is used, which is turned on by a key on a field-effect transistor.
Rotating part
Schematic diagram of the rotating part
Energy to the rotating part comes from the winding on the rotor. The voltage from the rotating part is supplied to a rectifier and stabilizer providing 5 V to power the microcontroller. At the input of the microcontroller there will be signals from the IR sensor from the remote control and the lever position sensor.
All LEDs are connected through transistors turned on in current source mode. Thus, the LEDs are protected from overvoltage, which can reach 40 volts. This voltage may vary depending on the LEDs turned on at the same time. The diode current can be taken equal to 50 mA, since the diodes operate in pulse mode.
This video shows an interesting clock called a propeller. It took three evenings to make them. Previously there was no good diagram of this clock. Now that a very good, simple and easy-to-assemble circuit has been found, the opportunity has arisen to repeat it. The schematic contains files with printed circuit boards. The clock circuit is simple, accessible to beginner radio amateurs who can make printed circuit boards and flash the controller.
Radio components can be bought cheaply in this Chinese store.
Why is the clock called a propeller? This design is rotated by a fan, that is, a computer cooler. As you can see, there is a control board with LEDs on the rotor. They create a clock effect. The LEDs are controlled by microprocessors, which at certain moments light up the LEDs and produce an image effect in the space of the dial.
In the video, the image flickers a little, but this is just an effect of video recording. In fact, everything shines very brightly and clearly, especially in the dark.
The video shows that you can correctly set the time and control the motor that rotates the LEDs.
The result was a very beautiful, interesting watch with an unusual mechanism and operating principle. About automatic watches.
Unusual dynamic LED clock powered by a motor from a hard drive.
Propeller watch
Device diagram:
Schematic diagram Photo: 1
Circuit diagram Photo: 2
Schematic diagram Photo: 3
Schematic diagram Photo: 4
Well, when all doubts are put aside, we can begin...
To make a propeller watch we will need:
* 2 sheets of fiberglass, one is double-sided (45*120mm), and the second is single-sided (35*60mm).
* Iron and Ferric Chloride (for etching boards).
* Motor from HDD drive.
* Soldering iron with a thin tip, mini-drill.
For watches:
* LED driver MBI5170CD(SOP16, 8 bit) – 4 pieces.
* Real time clock DS1307Z/ZN(SMD, SO8) – 1 piece.
* Microcontroller ATmega32-16AU (32K Flash, TQFP44, 16MH) – 1 piece.
* Quartz resonators 16MHz – 1 piece.
* Quartz resonators 32kHz – 1 piece.
* Ker. capacitor 100nF (0603 SMD) – 6 pieces.
* Ker. capacitor 22pF (0603 SMD) – 2 pieces.
* Ker. capacitor 10mF*10v (0603 SMD) – 2 pieces.
* Resistor 10kOm (0603 SMD) – 5 pieces.
* Resistor 200Om (0603 SMD) – 1 piece.
* Resistor 270Om (0603 SMD) – 1 piece.
* 2kOm resistor (0603 SMD) – 4 pieces.
* Clock battery and holder for it
* IR LED
* IR transistor
* LEDs (0850) 33 pieces (one of them (the last one) can be of a different color)
For the motor driver:
* TDA5140A motor driver – 1 piece.
* Linear stabilizer 78M05CDT – 1 piece.
* Capacitor 100 mF polar (0603 SMD) – 1 piece.
* Ker. capacitor 100 nF (0603 SMD) – 1 piece.
* Capacitor 10 mF polar (0603 SMD) – 2 pieces.
* Ker. capacitor 10 nF (0603 SMD) – 1 piece.
* Ker. capacitor 220 nF (0603 SMD) – 1 piece.
* 20 nF – 2 pieces.
* Resistor 10 kOm (0603 SMD) – 1 piece.
1) First we need to make 2 boards.
Printed circuit board bottom view
Printed circuit board top view
2) We are looking for an old unnecessary hard drive to remove the motor from it, in some hard drives the motor is not attached with bolts, but is pressed into the case, pay attention to this when choosing a hard drive, otherwise you will have to cut it out :)
Hi all! I would like to bring to your attention a simple propeller clock that I assembled on the Atmega8 controller. They are made from readily available parts and are easy to replicate and manufacture. The only thing is that you need a programmer to flash the clock controller and control panel.
A regular 120 mm fan (cooler) was used for the base of the clock. You can use any fans for this clock, both clockwise and counter-clockwise, because while I was assembling this clock, I modified the program a little and switched the display of symbols from the remote control programmatically.
The circuitry of the clock itself is quite simple and is assembled on an Atmega8 microcontroller, to synchronize its operation a clock quartz with a frequency of 32768 Hz is used.
The clock is powered by a receiving coil, the energy to which is transferred from a generator with a transmitting coil. Both of these coils make up an air transformer.
There were no particular problems with the circuit and design of the generator, since a generator from a plasma ball was used.
The generator is assembled on the common TL494 microcircuit and allows you to change the width and frequency of the output pulses over a wide range.
Even with a gap of a centimeter between the coils, the voltage is quite enough to start the clock. Just take into account that the larger the gap between the coils, the larger the pulse width needs to be made and, accordingly, the current consumption from the source increases.
When turning on the generator for the first time, set the pulse width (duty factor) to a minimum (the regulator knob is in the upper position according to the diagram, that is, leg 4 is pulled through resistor R7 to leg 14, 15, 2 of the TL-494). We turn the generator frequency until the squeak disappears, this is approximately 18-20 KHz (tuning by ear), and if there is something to measure the frequency, then we adjust it accordingly within these limits.
The generator board also contains an additional voltage regulator on LM317, designed to regulate the fan speed.
It’s not on the diagram, I didn’t draw it
. Watch a demo video of the clock in action.
The clock board itself is attached to the base of the fan. I secured it with double-sided tape.
Then I slightly modified the clock circuit from a photoresistor to an infrared photodiode (picture below).
Instead of a simple LED in the transmitter, I now have an infrared one.
The resistor was set to 100k instead of 2k.
The critical moments in the manufacture of a clock are the manufacture of an air transformer and alignment (or rather balancing) of the clock board on the base of the fan.
Take these moments more seriously.
It was based on a regular 120 mm cooler with bronze bushings. The clock board is glued to the base with double-sided tape.
We bite off the blades from the cooler and grind and level them with a file and sandpaper. The coils are made on a frame made of cable duct. I didn’t come up with this design, I just took this idea from the internet. To wind the transformer, a base is made from a cable channel. Every 5 mm we make a cut on the sides of the channel and carefully roll it into a circle; select the diameter so that it fits tightly on the plastic base of the fan.
Next, we wind 100 turns of enameled wire, 0.25 in diameter, onto the mandrel from the cable channel.
The current consumption of the assembled transformer turned out to be 200 mA (this is with a fairly noticeable gap between the coils).
In general, together with the fan motor, the current consumption is around 0.4-0.5A.
We do the same for the primary (transmitting) coil, but we try to make a minimum gap between the coils. The transmitting coil also contains 100 turns of 0.3 wire (or 0.25).
In the diagram I have slightly different winding data for these coils.
The strip with LEDs is made on fiberglass. A hole is drilled in it, a piece of tube from a telescopic antenna is inserted into this hole and soldered to the board (the antenna tube must be cleaned of the shiny coating). You can use any suitable tube, or attach the board in another way, for example using a screw with nuts.
I connected the board with LEDs to the clock board with a regular enameled (winding) wire; it is more rigid than the mounting wire and does not fray when rotated.
To balance the entire board, on the other side we glue a screw with a diameter of 3-4 mm with hot glue, screwing various nuts onto the screw on the other side - we achieve minimal vibration.
To check the functionality of the clock board, we short-circuit the photoresistor with a screwdriver or tweezers; the LEDs should blink.
The clock starts working when 5V (logical unit) appears on the 5th leg of the atmega. That is, when the photoresistor is illuminated, there should be 5V on the 5th leg,
When the photoresistor is not illuminated, there should be a logical 0 (about 0V) on the 5th leg of the atmega, for this we select a resistor to ground from the 5th leg. The diagram shows 2 kOhm, I got 2.5 Kohm.
At the bottom of the fan base we glue an LED so that with each revolution of the fan motor, the photoresistor passes as close as possible to the light source (LED).
The control panel is designed to control the operation of the clock, switch display modes (change the direction of fan rotation), and set the clock time.
The remote control circuit is assembled on an ATTINY2313 microcontroller. The board contains the MK itself with a harness and six buttons designed to control the clock.
I didn’t assemble the housing for the remote control, so only a photo of the board itself.
Information on the purpose of the remote control buttons;
H+ and H- clock settings
M+ and M- minutes setting
R/L change of direction (for screws rotating clockwise and counterclockwise)
font change font (thin, bold and website inscription)
When writing a site, use the H+ and H - buttons to adjust the width of the inscription.
The attached archive contains all the necessary files for assembling the watch;
Archive for the article
If you have any questions about the design of the watch, ask them on the forum, I will try to help and answer your questions as much as possible.
Remember these? Some time ago they conquered the Internet. It turns out it's a pretty common thing. See how you can make them yourself...
These funny electro-optical watch create the illusion that the numbers are hanging right in the air.
A rapidly rotating strip of seven LEDs is illuminated at certain points in time, which creates an optical effect that there is a discrete display measuring seven by thirty dots in front of your eyes. How do they work? propeller watch?
A small circuit board is mounted on the electric motor shaft, on which the electronic filling and seven LEDs arranged vertically are assembled. With rapid rotation, any point source of light is perceived by a person as a continuous strip of light. The microprocessor, in accordance with the embedded program, modulates (turns on and off) the backlight of each LED in time so that the effect of displaying numbers appears, which are as if suspended in the air, since the board itself flashes so quickly that the eye is not able to track its movement . A similar effect is used, for example, in a cathode ray tube, where at certain moments a signal is sent to a continuously scanning screen by an electron beam.
To download the original image from the author of the "clock-propeller" diagram
Design:
The clock is assembled on a small circuit board. This board with components and LEDs rotates on the shaft of an electric motor. The question arises about how to supply energy to the board? To solve this problem, various options have been considered. Firstly, you can use two motors: one main one, which rotates the circuit, and the second, located on its shaft, operating as a generator. You can also use a rotating transformer or slip rings. However, a more convenient way is to remove voltage from the rotor windings of the main motor. To do this, you need to subject the engine to a small modification: remove the bearing on one side of the shaft, leaving a free hole through which you can pass the wires.
Inside the motor there are three windings through which alternating current flows, out of phase by 120°. Wires need to be soldered to the ends of these windings, which are then connected to a three-phase rectifier on the board to obtain direct current again. The advantages of this method include the fact that at the same time it is possible to control the position of the electric motor shaft if one phase is connected to the measuring input of the microcontroller.
Refinement of the electric motor:
Take an unwanted spinner head motor from a Sharp or Samsung VCR. The motor used in this project is labeled JPA1B01, but according to the specification it is called RMOTV1007GEZZ. Carefully remove the brushes (through the small holes in the housing). Please note that the rotor is fixed at one end in a ball bearing, and the other end rests against a cover with a plain bearing, which must be removed. Glue or solder it on top of the ball bearing axle (on the other side) to strengthen the shaft. Adjust the height of the axle by holding it in a vise and tapping lightly. Solder three wires to three mounting pads on the motor rotor. Glue a small threaded bushing onto the axle on the side where it comes out of the hole, secure the conductors under it and assemble the motor. For greater structural stability, you can glue this motor to the video head unit.
Installation of electronic components:
The clock components are soldered to a circuit board with plated holes. The terminals are connected by conductors. An 18-pin socket must be installed for the 16C84 microprocessor, since it is programmed in a separate programmer. For seven load resistors R1B.R1H, it is convenient to use the corresponding resistor matrix in DIP design, which will allow you to experiment with the brightness of the LEDs. You can also use discrete resistors with a resistance of 120 Ohms. They work fine, albeit at the 16C84 pulse current limit. Think in advance about how you will balance this board so that there is room for it. You can replace components with others with similar characteristics. The author used a high-capacity storage capacitor of 47,000 μF in the circuit so that the clock readings were not reset after turning off the engine power during correction and time setting. You can use a 0.47 μF ionistor instead. Just remember that the LEDs must be powered bypassing it. You should use a ceramic resonator only at a frequency of 4 MHz, since the accuracy of the clock depends on it (or when using a resonator at a different frequency, you must make an appropriate modification of the program).
Programming 16С84
To program the 16C84 microcontroller, you can use any programmer available for this. The site contains a binary firmware file (download). The source code in assembly language can be found. When programming, be sure to set the following options: wathdog timer (WDT) - OFF, resonator. normal XT crystal.
Final assembly and timing:
Attach the board with parts and LEDs to the motor shaft. Solder three power leads. Apply voltage to the motor. The nominal voltage is 6.2 V, but you can change it in the range from 5 V to 7.5 V. Just be aware that due to the drop across the rectifier diodes, the 5 V on the board corresponds to a 6.2 V motor supply voltage. After applying voltage, the clock should display 12:00. If this is not the case, then perhaps the problem is that the storage capacitor has not completely discharged. Turn off the power and briefly short-circuit pins 4 and 5 together to reset the microcontroller. After this, you can turn on the power again, make sure that the clock is working, turn off the power and set the exact time using the “Hours”, “Tens of Minutes”, “Minutes” buttons. If the numbers are displayed backwards, reverse the polarity of the voltage on the motor. You can experiment with balancing the board, placing foam under the motor base to reduce vibration, etc.
With diagrams. and you get something like this:
Here's another option.
