Friday, April 29, 2011

Coding Step Respon In Mathlab

It is tutorial how to making listing step Respon in Software Matlab..
1. Open Mathlab

2. File .
        M file
Inside code   exsample


m=2;
b=5;
k=3;
A=[0 1;-k/m -b/m];
B=[0;1/m];
C=[1 0];
D=0;
state_space=ss(A,B,C,D)
press F5 
a =
         x1    x2
   x1     0     1
   x2  -1.5  -2.5
b =
        u1
   x1    0
   x2  0.5
c =
       x1  x2
   y1   1   0
d =
       u1
   y1   0
>> [A,B,C,D]=ssdata(state_space)
A =
         0    1.0000
   -1.5000   -2.5000

B =
         0
    0.5000
C =
     1     0
D =
     0
>> step(state_space)
you get it

And find transfer function you can make it.

>> tutorial_tf=tf(state_space)
Transfer function:
       0.5
-----------------
s^2 + 2.5 s + 1.5

>> 
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Tuesday, March 29, 2011

Analog - Digital With Matlab


For a better understanding of how to specify device settings when using both analog and digital signals, this section uses the I/O board DAS-1601 from Keithley-Metrabyte as an example. The following is a specification summary of the DAS-1601 board:

  •  Analog input (A/D) -- 16 single-ended or 8 differential analog inputs (12-bit), polarity is switch configured as either unipolar (0 to 10 volts) or bipolar(+/- 10 volts). Gain is software configured to 1, 10, 100, and 500. 
  • Digital input -- Four unidirectional digital inputs Analog output (D/A) -- Two
  •  analog outputs (12-bit). Gain is switch configured as 0 to 5 volts, 0 to 10 volts, +/- 5 volts, or +/- 10 volts 
  • Digital output -- Four unidirectional digital outputs 
  • Base address -- Switch configured base address 
This section explores different configurations for input signals. Once an Analog Input block has been placed in the model and the I/O board selected and configured, you can set up the Analog Input block to handle input signals. Single analog input -- The most basic case is for a single analog input signal that will be physically connected to the first analog input channel on the board. In the Block Parameter: Analog Input dialog box, and the Input channels box, enter 1 or [1]

The use of brackets is optional for a single input. Input vector with differential analog -- Analog channels are numbered starting with channel 1 and continue until you reach a number corresponding to the maximum number of analog signals supported by the I/O board. In the case of the DAS-1601, when configured as differential inputs, eight analog channels are supported. The analog input lines are numbered 1 through 8. The complete input vector is

[1 2 3 4 5 6 7 8] or [1:8]

If you wanted to use the first four differential analog channels, enter
 [1 2 3 4]
Input vector with single-ended analog -- Now, assume your DAS-1601 board is configured to be single-ended analog input. In this case, 16 analog input channels are supported. The complete input vector is
 [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16] or [1:16]
To use the first four single-ended analog input channels, enter
 [1 2 3 4] or [1:4]

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Monday, March 28, 2011

IR232 Infrared to RS-232 Converter


The Industrologic IR232 is an infrared to RS-232 converter that is based on the 12 bit Sony SIRCS protocol. In addition to being able to send and receive control codes to and from the infrared and RS-232 ports, it can also be configured to send specific character strings to the serial port when selected infrared codes are received. This will allow it to act as a host and controlling device to any slave device that can accept RS-232 commands.



On-board 40 KHZ infrared receiver module and 940nM high-power infrared LED Visible LED to confirm reception of infrared transmissions
EEPROM for storage of configuration information and character strings Multiple modes of operation available-
- Send programmed messages when specified infrared codes are received
- One and two byte binary transmission and reception
Serial port with true RS-232 interface and DB9F connector matching PC compatibles
Selectable baud rates up to 19200 baud
Pin-type power jack for easy connection to wall block power supply
On-board +5 volt power supply with +5 volt output available on DB9 for auxiliary devices
Includes all items needed for immediate use: Wall block power supply, RS-232 cable for connection to PC compatibles during setup, and terminal emulation software for PC compatibles.

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Tuesday, March 8, 2011

Simple Switch On Time Delay Circuit

This Switch On Time Delay circuit has been designed to create a lamp switch operated electronically with an option of setting a delay in the time of execution of operation to reduce one or more lamps in a stairwell or any other places where this circuit may be useful. The circuit can be useful to control various lamp or appliances that can be connected in relay contacts.

The circuit that takes advantage of the emitter/base breakdown voltage of an ordinary bi-polar transistor. The reverse connected emitter/base junction of a 2N3904 transistor is used as an 8 volt zener diode which creates a higher turn-on voltage for the Darlington connected transistor pair. Most any bi-polar transistor may be used, but the zener voltage will vary from about 6 to 9 volts depending on the particular transistor used. Time delay is roughly 7 seconds using a 47K resistor and 100uF capacitor and can be reduced by reducing the R or C values. Longer delays can be obtained with a larger capacitor, the timing resistor probably shouldn't be increased past 47K. This Switch On Time Delay circuit should work with most any 12 volt DC relay that has a coil resistance of 75 ohms or more. The 10K resistor connected across the supply provides a discharge path for the capacitor when power is turned off and is not needed if the power supply already has a bleeder resistor.
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Tuesday, February 22, 2011

ReWalk robotic exoskeleton

ike the REX robotic exoskeleton, ReWalk is a wearable, motorized robotic device that is worn outside the clothing. The motorized legs, which are held in place by leg braces and a harness worn around the waist and shoulders, are powered by a rechargeable battery providing 3.5 hours of use located in a backpack along with a computer. However, unlike the REX exoskeleton which is controlled by a joystick, the ReWalk uses motion sensors to detect the wearer’s movements and translate them into movement of the units’ motorized joints, similar to the eLEGS exoskeletondeveloped at UC Berkeley.

Unlike the robotic exoskeletons being developed mainly for military use, such as Lockheed Martin’s HULC and Raytheon’s XOS robotic exoskeletons, which are designed to amplify the wearer’s movements giving them increased strength, speed and endurance, ReWalk is controlled by detecting the subtle movements in the user’s center of gravity and upper-body movements.
For this reason the user needs crutches to assist with their balance when using ReWalk, which means it is only suitable for those with movement in their hands and shoulders. Unfortunately this means Goffer, who is a quadriplegic, isn’t able to use his creation. However, Argo Medical Technologies – the company he founded to commercialize the device – is working on a version suitable for quadriplegics.
The ReWalk weighs 15 kg (33 lbs.) and is designed to serve as a physical training device for those undergoing rehabilitation. By maintaining users upright on a daily basis it also helps alleviate many of the health-related problems associated with long-tern wheelchair use such as urinary, respiratory, cardiovascular and digestive problems.
The ReWalk has been undergoing clinical trials in Israel and the U.S. for several years and Argo Medical Technologies now plans to start selling the device to rehabilitation centers around the world from January 2011 for a cost of around US$100,000.
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Monday, February 21, 2011

HyperSolar concentrator could boost solar cell output by 400 percent

Solar cells are the most expensive part of a solar panel, so it would follow that if panels could produce the same amount of electricity with less cells, then their prices would come down. In order for panels to be able to do so using existing cell technology, however, they would need to get more light to the fewer cells that they still had. Mounting the panels on the end of vertical poles to get them closer to the sun is one possible approach, that might work in the town of Bedrock or on Gilligan’s Island. A better idea, though, is to apply a clear layer of solar concentrators to the surface of a panel – and that’s just what HyperSolar intends to do.

The California company claims that it has just completed the prototype design of “the world’s first thin and flat solar concentrator for direct placement on top of existing solar cells.” Each sheet will contain a matrix of optical concentrators that are capable of collecting sunlight from a variety of angles. Beneath those concentrators will be a “photonics network,” that will channel light from all the collection points on the top to concentrated output points on the bottom. This network will also able to separate the sunlight into different spectrum ranges, so that specific ranges can be sent to specific cells designed to absorb them.
The sheets will also incorporate a photonics thermal management system, that will keep unusable parts of the solar spectrum from reaching the cells. This should keep the cells from overheating, and becoming less efficient.
While HyperSolar predicts that its product will be able to magnify the sun’s rays by 300 to 400 percent, not all cells will necessarily be able to handle that kind of intensity. For that reason, the solar concentrators will come in Low Magnification, High Magnification, and Mix-Mode Magnification models. At the 400 percent level, the company states that a concentrator-equipped panel could use 75 percent less cells than one without.
HyperSolar’s next step will be to produce an actual physical prototype, and see if it works as envisioned. We’ll keep you posted ...
From
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