Showing posts with label this. Show all posts
Showing posts with label this. Show all posts

Thursday, December 26, 2013

This can also expand the brand mobile phone manufacturers

cell phone jammer can help the school prevent students against using the cell phone in the improper time.
Recycling of electronic products under the generally applicable "producer responsibility" principle, responsible for waste recycling mobile phones and other electronic products, primarily responsible for the use of the mobile phone manufacturer, that manufacturer should be used mobile phones and other electronic products recycling and utilization of play a major role. Major brand mobile phone manufacturers should set up a special cell phone recycling organization will be incorporated into the service of mobile phone recycling. Can be recycled to the cell phone repair and renovation of the old channels after the regular sale to economically underdeveloped areas, to expand sales of mobile phone market. This can also expand the brand mobile phone manufacturers, mobile phone manufacturers such behavior will be recognized by consumers. For businesses, reputation is an intangible asset. The most important thing is good publicity, so that users know that mobile phones and other electronic products recycling pathway. Can hold a number of recycling activities can enhance the users participation in environmental awareness. Innovation and recovery, so that people in the process of recycling used batteries to get a sense of psychological pleasure; paid recycling, so that people get the corresponding labor compensation; publicity and education so that people value their sense of identity recovery behavior. However, the low return rate for disposal of batteries, long cycle efficiency, it is difficult to attract investors, so it is difficult to form industrial scale, and produce benefits. In fact, used cell phone battery recycling industry is not profitable. Contains a large number of used cell phone batteries can be recycled such as heavy metals and acid substances, such as lead-acid battery recycling mainly recycling of lead-based waste, but also for the use of waste acid and plastic casing.  With the popularity of mobile phones, used cell phone batteries have become a special type of e-waste, the current cell phone batteries are Cd-Ni, MH-Ni and Li-ion three types of batteries, Cd-Ni battery is the main pollutants Ni, Cd and KOH, nickel-metal hydride battery is the main pollutants Cd, Cu and KOH, lithium-ion battery is the main pollutant Co, Mn and organic electrolytes. The resulting environmental pollution and waste of resources has become increasingly prominent. Used cell phone batteries on the environment and human health hazards mainly from the one containing the acid, alkali and heavy metals such as electrolyte solution. At present, China is mainly used mobile phone batteries with household waste in landfills, incineration, composting and other methods for processing, and waste batteries if the joint deal with the garbage man will be brought to the environment and great potential harm.
Continue Reading..

Sunday, April 7, 2013

Make this Temperature Indicator Circuit with Sequential LED Display

In some of my earlier articles we have seen a few simple and interesting temperature indicator circuits. All these circuits are useful in some or the other ways, however these are not equipped with  step wise temperature level indicator arrangement and therefore tracking the varying levels of temperature cannot be identified using them.

The present design eliminates the above issue, as here the entire temperature range becomes visible through an arrangement of an LED array.
The LEDs in this circuit reads the temperature levels discretely via 20 steps of LED indications.
The proposed sequential LED temperature indicator circuit is definitely the simplest to build, since it is based on a single outstanding IC LM3914 from TEXAS INSTRUMENTS, which single handedly performs the whole action of displaying the readings in a sequential manner.
The LEDs show an incrementing temperature through a single illuminated LED at the relevant positions of the array, thus the present design shows a dot mode indication instead of a bar graph. The dot mode arrangement specifically helps to save battery power because only one LED is involved for the required indication at any instant.  

The IC LM3914 is basically a millivolt measuring device which is able to convert a varying milli volt input into a corresponding LED readout at its output pin outs.

Here the input is derived from another interesting IC LM35 from TEXAS INSTRUMENTS, which is configured as an ambient temperature sensor device.

The IC LM35 coverts the temperature differences around it, directly into varying milli volts across its output.
For every single degree change in the temperature, the IC LM35 generates an output with a 10 mV variation.
This correspondingly varying milli volts is applied at the input of the IC LM3914, which readily accepts these variations, making them visible at the output through the connected LEDs.
Thus as the temperature around the IC LM35 increases, it generates a correspondingly increasing mV  across its outputs which is in turn transformed by the IC LM3914 into an LED readout, displaying the relevant level of the sensed temperature.
The LED array should be appropriately calibrated, through some trial and error and some practical experimentation.




Continue Reading..