birt barcode open source Figure 6-11. Potentiometer blue axle peg mounting fixture in Font

Generator QR Code in Font Figure 6-11. Potentiometer blue axle peg mounting fixture

Figure 6-11. Potentiometer blue axle peg mounting fixture
QR-Code Printer In None
Using Barcode creation for Font Control to generate, create QR Code image in Font applications.
www.OnBarcode.com
Code 39 Full ASCII Encoder In None
Using Barcode generation for Font Control to generate, create Code 3/9 image in Font applications.
www.OnBarcode.com
Figure 6-12. Fully seated
Draw Barcode In None
Using Barcode encoder for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Paint USS-128 In None
Using Barcode creator for Font Control to generate, create USS-128 image in Font applications.
www.OnBarcode.com
CHAPTER 6 POTENTIOMETER SENSORS
UPC-A Supplement 2 Generation In None
Using Barcode drawer for Font Control to generate, create UPC-A Supplement 2 image in Font applications.
www.OnBarcode.com
Generating PDF417 In None
Using Barcode generator for Font Control to generate, create PDF417 image in Font applications.
www.OnBarcode.com
NXT Protractor
Create European Article Number 13 In None
Using Barcode printer for Font Control to generate, create European Article Number 13 image in Font applications.
www.OnBarcode.com
UPC E Printer In None
Using Barcode drawer for Font Control to generate, create UCC - 12 image in Font applications.
www.OnBarcode.com
Converting the measured Raw value into an angle only requires a little algebra. Rpot isn t a variable because it doesn t change once you pick the pot, so you can simplify the equation a little. This equation is coded in Figure 6-13 to make a NXT protractor that reads the pot angle and displays it on the screen.
Read Quick Response Code In VB.NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Create QR Code In Visual Basic .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create QR Code 2d barcode image in .NET framework applications.
www.OnBarcode.com
2,700,000 Raw Rpot (1023 Raw )
Painting Matrix 2D Barcode In Visual Studio .NET
Using Barcode maker for Visual Studio .NET Control to generate, create Matrix Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Recognize EAN / UCC - 13 In Visual C#
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
[degrees] where G = 54 for the 50k , 135 for the 20k , and 270 for the 10k
Barcode Decoder In Visual Basic .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
GS1 DataBar Limited Creator In Java
Using Barcode encoder for Java Control to generate, create GS1 DataBar Stacked image in Java applications.
www.OnBarcode.com
G Raw 1023 Raw
Making ECC200 In Java
Using Barcode printer for Java Control to generate, create ECC200 image in Java applications.
www.OnBarcode.com
EAN / UCC - 13 Creator In .NET
Using Barcode generation for Reporting Service Control to generate, create GTIN - 13 image in Reporting Service applications.
www.OnBarcode.com
Figure 6-13. NXT-G protractor program
Decoding Code128 In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Making PDF 417 In Java
Using Barcode maker for Java Control to generate, create PDF-417 2d barcode image in Java applications.
www.OnBarcode.com
Pressure Sensor
Paint UCC-128 In Objective-C
Using Barcode generation for iPad Control to generate, create EAN / UCC - 13 image in iPad applications.
www.OnBarcode.com
Barcode Drawer In .NET Framework
Using Barcode drawer for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
Figure 6-14 shows how you can combine a potentiometer and a LEGO pneumatic cylinder to make a simple pressure sensor. The pneumatic cylinder tries to extend its piston when pressure is applied to the lower input, but two rubber bands resist the motion. The rubber bands exert a force that is linear with the amount they are stretched, so the extent the pneumatic cylinder moves is directly related to the pressure in the cylinder. As the piston is pushed outward, it rotates a connecting arm connected to the pot. Because the total rotation is only about 90 degrees, use the 50k pot.
CHAPTER 6 POTENTIOMETER SENSORS
Figure 6-14. Pressure sensor using pneumatic cylinder and 50k pot
LEGO rubber bands come in a variety of sizes and are color coded. Blue ones are large enough that they are barely stretched with the piston in the starting position. White ones are small enough that they are already stretched in the same position. You need to pick a color or combination of colors to set the range of pressures you want to measure. Figure 6-15 shows the pressure ranges we measured with two blue, one blue and one white, and two white rubber bands.
Figure 6-15. Raw versus pressure for three different rubber band combinations
CHAPTER 6 POTENTIOMETER SENSORS
Broom Balancer
You can probably balance a broom by the end of its handle on the open palm of your hand. It s not that hard because the broom s center of gravity is way up near the bristles, and it can t move as quickly as you can move the handle. Designing a machine that can balance a broom like this is not as easy as it might seem. People have earned PhDs in engineering studying this control problem. Although the example in Figure 6-16 works, it s just a starting point for further experimentation.
Figure 6-16. Broom and balancer cart
CHAPTER 6 POTENTIOMETER SENSORS
The 20k pot is an excellent angle sensor for this application because it rotates with little friction, and only 180 degrees of motion is needed. The angle sensor is mounted so that the angle of the broom is directly measured. For simplicity, the Raw value is not converted to a true angle. You need to wire the pot for counterclockwise operation if it s mounted exactly as in Figure 6-17. You also need to adjust it so the 0 position is near the point where the broom is lying horizontally toward the bottom of the NXT.
Figure 6-17. Close-up of pivot mount for broom handle
The NXT motors are internally geared down, and unfortunately their speed is a little slow for this application. You need the cart to move quickly to correct for the broom tilting even a little. The gear train shown in Figure 6-18 multiplies the motor speed by 3. The two gear trains are in parallel to increase the torque-handling capability.
CHAPTER 6 POTENTIOMETER SENSORS
Figure 6-18. Close-up of gear train for broom cart wheels
The broom handle is made from a 3/16 inch (4.75mm) diameter, 25 inch (64cm) long wooden dowel rod. You can fasten it to the angle sensing axle in a variety of ways. Our favorite is to use two Technic socket joints, as shown in Figure 6-19. The dowel rod is pushed through the two holes on the sides of the joint sockets. A 2.5 inch (6.4cm) diameter Styrofoam ball tops the pole to make it act more like a broom.
Figure 6-19. Example broom handle holder
The main program for the broom balancer is illustrated in Figure 6-20 and has two parts. The broom must be initially vertical and in the balanced position when the program is started. This position is remembered as X. Then the program goes into the endless loop of updating the control and driving the motor.
Copyright © OnBarcode.com . All rights reserved.