CAPACITIVE SENSOR

 

((WO/2009/102228) PLANAR CAPACITIVE PROXIMITY SENSOR

(WO/2009/110814) STANDUP SENZOR

link to: http://boban-stojanovic.blogspot.com/

 

 

 

Reduction of consumption of wireless optical computer mouse:

Optical wireless computer mouse when not active uses approximately 300-100 micro A. I have tested the Microsoft Notebook Optical Mouse 3000 model. Depending on intensity of usage, its battery lasts about six months.
By adding the capacitive sensor, its consumption in stand by regime would be reduced about 50 times. It is easy to assume that for an average consumer the battery would last much longer. By adding the capacitive sensor, the life of the battery would be extended, and the sensor would pay off immediately because the price of the entire electronics in mass production is around 10-15 cents, which is similar to the difference between alkaline and regular battery. The device is a part of my work of many years P-04396RS (19.07.2006), International application : (28.05.2007) No:-WO/2008/010739 for which there are several applications in national or international phase. I will describe the sensor in brief. The sensor consists of a-stabile multi-vibrator as an oscillator. Besides the astabile multivibrator , there are the two electrodes of sensor variable capacitor. The two pieces of 2cm copper wire could be used as electrodes. When there is a conductor or an electrolyte near electrodes and that can also be a hand, it makes the in-line containing power Cx=0,1pF in the variable capacitor Cx. The capacity induces the astbile multivibrator to oscillate with the adequate amplitude to induce the rest of the circuit. As inverted converters I have used six integrated inverters in IC IC4069 CMOS. The standard CMOS circuits of 4000B series give better results than in case of HCT or HC gates, because with smaller consumption they give greater sensitivity of the device. The device can be constructed with other gate series. For standard CMOS circuits and integrated circuit, CMOS 4069 here are some characteristics: Operating voltage: from 2,3V to 3,1V. Electric current consumption: from 3 to 5 micro A.Detection area: from 0.3-2 cm depending on circuit perimeters . The sensitivity is easy to adjust even in arrange of 1cm. When an electrolyte or hand is detected the device is noise resistant. Even near the mobile phones, obstructions or errors are not induced. Forasmuch as the device with the variable capacitor is somewhat impractical to install in optical mouse, besides the classic sensor I have also added in my patent the realization of sensor with only one electrode. Capacitive sensor with one electrode consists of one electrode, which can be a piece of wire and a a-stabile multi-vibrator . The second electrode of the capacitive sensor Cx is a virtual electrode, which is the power supply i.e. the battery. This realization is more practical to upgrade since one piece of the wire can be easily put anywhere in the device and by that a hand could always be detected.
Whereas the device functions on operating voltage of 2,3 to 3 V for some optical mice which need 1,5V batteries it would be inapplicable. For some device which need 1,5V batteries it would be used 74HC04.

The capacitive sensor could be applied in computer keyboards, gamepads and remote controls:

If instead of a hand contact by pushing the button, we replace the construction and install the capacitive sensor, we would get the pushbutton that could not break down. For capacitive sensor, there is no need of any kind of contact. Electrodes of push buttons are insulated. When a finger pushes a button a rubber part of the button with electrodes makes some condenser which activates sensor. Suchlike construction of the buttons on a keyboard gives almost infinite lifetime of the keyboard. Beside the a-stabile multi-vibrator , it is necessary to add an analogue mixer and de-mixer. The price of theses keyboards would be similar and even if the additional electronics were made separately, it would be more economical for PCB keyboards since there is no need for a graphite therefore the construction of passive part of the keyboard is much simpler. The device is also possible to realize as a sensor matrix, therefore the detection of the finger would be possible, and as a quite practical usage, it could appear in remote controls and keyboards in which case there will not be need for contact or a chance for the devices to break. It happened to all of us that a button on a remote control would not work. By using the capacitive sensor in a keyboard or a remote control, breakdowns would be impossible.

Aplikant

Stojanovic Boban

Andje Rankovic 10/4/8
35230 Cuprija

Serbia

TEL/FAX:+381-35-475-597
mob:+381-64-300-5375

strob@ptt.rs