Hello everybody, I am Chadua. This is my first project here in instructables.
We will make a Luminous mat (40x50cm) that generates power by each footstep. The power generated is used to light the logo up. Impress your visitors with a warmly and shinning welcome. lets get started!
Step 1: Materials
It is needed:
1. 15 Leds (Figure 3.1)
Get them here: https://www.ebay.com/itm/100-Pcs-5mm-Red-Green-Whi...
2. 12 Vibration generators(piezoelectric) (Figure 3.2)
Get them here: https://www.ebay.com/itm/10pcs-Piezoelectric-Piez...
3. 12 Smd bridge rectifier smd 1A(Dip Bridge can be use too) (Figure 3.3)
Get them here: http://mexico.newark.com/multicomp/abs10/bridge-re...
4. Rainbow Wires(It is recommended this kind of wire because of flexibility) (Figure 3.4)
Get them here: https://www.ebay.com/itm/5M-10-Pin-Rainbow-Color-F...
5. Sillicone(Figure 3.5)
6. Virgin copper sheet(Figure 3.6)
7. Soldering iron(Figure 3.7)
8. 2 Vinyl mesh mat(Figure 3.8)
You should to find a company (http://www.dustcontrol.com.mx/) that manufacture personalized vinyl mesh mat in your country. It will be needed to two mats in this case, base and surface. In the base, it will be made grooves to place the sensors and circuit. In the surface is where the logo or message and leds will be located. Finally, Surface and base will be fusioned.
8.1 Vinyl personalized mesh mat (LogoSurface) (Figure 3.9)
8..2 Vinyl mesh mat (Base) (Figure 4.0)
The second mat is the base where the sensors and circuit will be placed and assembled.
9. Contact adhesive U-7200(Figure 4.1)
A little bit of this adhesive can be asked for at mat company to save some coins or well, purchase a adhesive that works on rubber and PVC
10. Cutter(Figure 4.2)
Step 2: Circuit Desing
The following step is about how it works, at firts we need to get how the piezoelectric generator works.
WHAT IS PIEZOELECTRICITY? Piezoelectric materials are produce an electric voltage when deformed mechanically—such as by squeezing or tapping. The reverse effect is also true. If we apply a voltage to the material, it deforms.
Altern current is the signal generated by piezo material. It means the current can be posive or negative when the piezos are deformed. it is only need positive voltage to turn leds on, so that, each signal generated will pass through bridges rectifier.
The second image(figure 5.1) shows us how we need to connect the piezos with bridges. The bridges have to be connected in parallel like third image(figure 5.2). The parallel connection is more efficient because we need to increase the current, the peak voltage generate by piezo is so high (15-25Vpp). The negattive terminal (ground) has to be connected with every negative terminal as the same as possitive terminals (figure 5.2).
To connect the Leds, the third image shows us how to do it: The are 15 leds so they are divided by 3 leds connected in series. Led1(-+) Led2( -+) Led3( -+), do that connection with other leds. When every third is connected in series, the following step is to connected in paralled like the fourth image (figure 5.3).
Note: In this case we don`t need a resistor because of small energy generated by piezo, the importan thing is the leds shine as much as they can, and the resistor will take energy to avoid it. Then we have possitve led pin that will be connected to possitive bridge possitve pin and as the same conecction as negative pins (figure 5.4).
The pdf and proteus file are attached. You need to print PDF in acetate paper (laser printer can only do it), this simple video show you how:
Step 3: Assembling
Now, we make the grooves with cutter (figure 5.7) to place the sensors and the pcb (Figure 5.9).
Then, the piezos needs to be stuck with something like rubber (figure 5.8). We are going to need more sensibility when we step so the piezos will be placed with some inclnation.
The next step is to solder longer wires to piezo and then joing to pcb..
Then, the leds are placed on surface (figure 6.1 & 6.0).Leds need to be soldered with long wires and then sillicone will be used to protec leds pin, so sillicone will be placed below leds (figure 6.2).
The next step is to connect the leds to the outputs of pcbs (figure 6.3).
The last thing is put contact adhesive U-7200 for all the base mat perimeter and then place the surface. Let dry one hour. Once the one hour finishes, put it on home entrance(figure 7.0).
Do you want luminous mat to brighter? I will make a tutorial where we make a luminous mat with a power source and microcontroller, yes it will not self sustaining but It will impact by far your visitors. See you the next time.