DIY - projection clock.
I hope those who were on my portal saw the first version of the projection clock. I made the second. This article partly duplicates that material. And partly reveals the rake on which I stepped. No microcontroller inside, available for repetition to all!)
Let's start with the materials. The main design of the watch is made of thick dense cardboard, such cardboard is used for book crusts or inserted into the cover of folders for rigidity. The cylinder is a sleeve from a sticky roller from IKEA. The cheapest Chinese watches were bought as watches:
')
Lenses, however, were purchased and ground under the order in optics - 2 glass lenses for +25 diopters. In principle, you can use any lenses. For example, buy simple Chinese plastic binoculars and remove the lenses from the eyepieces (they are made of optical polystyrene because they are very easy to scratch, be careful). The LED was purchased in the store, L-813. The power supply unit Robiton was purchased in the hozmage for 160 rubles (3-12Vb 300 mA).
We will use an ordinary luster cartridge for lamps as an eyepiece, it has an external thread and a special nut. That allows just the rotation to adjust the focus.
Display
The first step is to make the display of digits working on the clearance. We disassemble the clock and remove the board. At the liquid crystal display, it is necessary to peel off one film-polarizer, to wipe it off from the glue with ethyl alcohol. After we turn it over we get an inverse display, black turned off and transparent turned on.
If the films are opaque, then it is desirable to remove them and replace them with glossy ones, otherwise a significant part of the light flux will be lost.
In place of the board we will install the scarf made by us. Last time we used a loop, but this detail is quite specific, so this time we will make a more affordable option - a special handkerchief. View of her in the photo:
The dividing grooves are cut with a stationery knife. Gently solder it with wires to the clock board and collect. It turns out something like:
Light-emitting diode
Usually the current through the LED is 20 mA. The last time the current was greater due to the fact that, as it turned out, the key fob manufacturers do not worry about the service life of the LED because Batteries are low. And their replacement is not supposed. As a result, the LED quickly went out of order. This time it was decided to use a color super-bright LED. To use it you have to count a little. Opening the passport to the LED (datasheet in bourgeois terminology) let's see 2 important parameters - the maximum current (DC Forward Current) and the forward voltage drop (Forward Voltage). In this case, we get 2.5V 25 mA. Suppose we will power the LED from 12 volts. Then you need to put such resistance. What would fall on it 12 - 2.5 = 9.5V at a current of 20 mA (we will reserve 5 mA). According to Ohm’s law, R = U / I
R = 9.5 / 0.02 = 475 ohms.
Optics
Our optics are pretty simple - only 2 lenses. Optical scheme with dimensions for lenses +25 diopters in the figure:
The figures are approximate. These distances were obtained empirically - the LED was clamped in the yews, the “third hand” device held the screen in such a way that the light cone illuminated all the numbers completely, a lens lay on top of the screen, and the optimal distance for the lens was adjusted with a ruler picture on the ceiling.
The LED gives a cone light. The light passing through the display is corrected (the divergence decreases) with lens number 1. Then the light passes through lens objective number 2 and then projected onto the surface.
If we get rid of the lens number 1, we get the ray path as in the second part of the circuit. Extreme rays that carry information about the picture along the edges will go beyond the limits of the optics and not fall on the lens of lens number 2. It will look like a bright center with a picture and dark edges.
The ideal case is depicted in 3 parts of the scheme - the screen is illuminated by parallel beams, which are then assembled by lens number 2.
The stronger lenses we put, the larger the picture on the wall will be (although its brightness will be low, because the same amount of light falls on a larger area. But the more powerful the lenses are, the stronger the distortions will be. To reduce distortion, you need to diaphragm the light flow, but it will reduce the brightness. You get such contradictory requirements.
I tried to use a 3-watt green LUXEON LED as a light source and I didn’t get anything good. This LED has a very large divergence of the beam, as a result it turned out that only the center of the image was highlighted (see the optical scheme). With a set of lenses, it was possible to correct the light beam, but it was weakened so much that there was no advantage over the usual super-bright LED.
Assembly
Carefully cut the cardboard and paint all the internal surfaces in black to eliminate all internal reflections. When assembling, strictly observe the optical axis, otherwise the picture will be distorted. We solder the control buttons to the clock microcircuit and solder the battery inside. Of course, it was possible to make a power supply stabilizer, so that 1.5V voltage would come from the power supply, but this is excessive complexity. Having finished the assembly of the main part, you can sheathe it with cardboard and glue it with film. In general, everything is clear from the photos:
picture projected by the clock in the photo: (shutter speed is large, so the brightness seems higher)
Original article: licrym.org/wiki/index.php?wakka=SdelajjSam/ProekcionnyeChasy2
UPD . As for the cross-posting and copy-paste.
This article was published today on the portal and duplicated here. More than anywhere else, the article did not cross me anywhere, and will not cross post (due to the absence of large specialized resources).
Secondly, I completely published an article here, due to the fact that previous experience showed that my server (home machine with megabit channel) was not able to handle all visitors, there were many complaints about inhibition and inaccessibility
Let's start with the materials. The main design of the watch is made of thick dense cardboard, such cardboard is used for book crusts or inserted into the cover of folders for rigidity. The cylinder is a sleeve from a sticky roller from IKEA. The cheapest Chinese watches were bought as watches:
')
Lenses, however, were purchased and ground under the order in optics - 2 glass lenses for +25 diopters. In principle, you can use any lenses. For example, buy simple Chinese plastic binoculars and remove the lenses from the eyepieces (they are made of optical polystyrene because they are very easy to scratch, be careful). The LED was purchased in the store, L-813. The power supply unit Robiton was purchased in the hozmage for 160 rubles (3-12Vb 300 mA).
We will use an ordinary luster cartridge for lamps as an eyepiece, it has an external thread and a special nut. That allows just the rotation to adjust the focus.
Display
The first step is to make the display of digits working on the clearance. We disassemble the clock and remove the board. At the liquid crystal display, it is necessary to peel off one film-polarizer, to wipe it off from the glue with ethyl alcohol. After we turn it over we get an inverse display, black turned off and transparent turned on.
If the films are opaque, then it is desirable to remove them and replace them with glossy ones, otherwise a significant part of the light flux will be lost.
In place of the board we will install the scarf made by us. Last time we used a loop, but this detail is quite specific, so this time we will make a more affordable option - a special handkerchief. View of her in the photo:
The dividing grooves are cut with a stationery knife. Gently solder it with wires to the clock board and collect. It turns out something like:
Light-emitting diode
Usually the current through the LED is 20 mA. The last time the current was greater due to the fact that, as it turned out, the key fob manufacturers do not worry about the service life of the LED because Batteries are low. And their replacement is not supposed. As a result, the LED quickly went out of order. This time it was decided to use a color super-bright LED. To use it you have to count a little. Opening the passport to the LED (datasheet in bourgeois terminology) let's see 2 important parameters - the maximum current (DC Forward Current) and the forward voltage drop (Forward Voltage). In this case, we get 2.5V 25 mA. Suppose we will power the LED from 12 volts. Then you need to put such resistance. What would fall on it 12 - 2.5 = 9.5V at a current of 20 mA (we will reserve 5 mA). According to Ohm’s law, R = U / I
R = 9.5 / 0.02 = 475 ohms.
Optics
Our optics are pretty simple - only 2 lenses. Optical scheme with dimensions for lenses +25 diopters in the figure:
The figures are approximate. These distances were obtained empirically - the LED was clamped in the yews, the “third hand” device held the screen in such a way that the light cone illuminated all the numbers completely, a lens lay on top of the screen, and the optimal distance for the lens was adjusted with a ruler picture on the ceiling.
The LED gives a cone light. The light passing through the display is corrected (the divergence decreases) with lens number 1. Then the light passes through lens objective number 2 and then projected onto the surface.
If we get rid of the lens number 1, we get the ray path as in the second part of the circuit. Extreme rays that carry information about the picture along the edges will go beyond the limits of the optics and not fall on the lens of lens number 2. It will look like a bright center with a picture and dark edges.
The ideal case is depicted in 3 parts of the scheme - the screen is illuminated by parallel beams, which are then assembled by lens number 2.
The stronger lenses we put, the larger the picture on the wall will be (although its brightness will be low, because the same amount of light falls on a larger area. But the more powerful the lenses are, the stronger the distortions will be. To reduce distortion, you need to diaphragm the light flow, but it will reduce the brightness. You get such contradictory requirements.
I tried to use a 3-watt green LUXEON LED as a light source and I didn’t get anything good. This LED has a very large divergence of the beam, as a result it turned out that only the center of the image was highlighted (see the optical scheme). With a set of lenses, it was possible to correct the light beam, but it was weakened so much that there was no advantage over the usual super-bright LED.
Assembly
Carefully cut the cardboard and paint all the internal surfaces in black to eliminate all internal reflections. When assembling, strictly observe the optical axis, otherwise the picture will be distorted. We solder the control buttons to the clock microcircuit and solder the battery inside. Of course, it was possible to make a power supply stabilizer, so that 1.5V voltage would come from the power supply, but this is excessive complexity. Having finished the assembly of the main part, you can sheathe it with cardboard and glue it with film. In general, everything is clear from the photos:
picture projected by the clock in the photo: (shutter speed is large, so the brightness seems higher)
Original article: licrym.org/wiki/index.php?wakka=SdelajjSam/ProekcionnyeChasy2
UPD . As for the cross-posting and copy-paste.
This article was published today on the portal and duplicated here. More than anywhere else, the article did not cross me anywhere, and will not cross post (due to the absence of large specialized resources).
Secondly, I completely published an article here, due to the fact that previous experience showed that my server (home machine with megabit channel) was not able to handle all visitors, there were many complaints about inhibition and inaccessibility
Source: https://habr.com/ru/post/39784/
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