Check patentability & draft patents in minutes with Patsnap Eureka AI!

Capacitance type touch key system and micro-control unit thereof

A technology of micro control unit and button system, applied in the direction of electrical components, electronic switches, pulse technology, etc., can solve the problems of high cost, complex adjustment, large temperature drift, etc., and achieve low cost, simple peripheral circuit, and small temperature drift Effect

Inactive Publication Date: 2010-12-08
SINO WEALTH ELECTRONICS
View PDF4 Cites 22 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a capacitive touch key system to solve the problems of large temperature drift, high cost and complicated adjustment caused by the complex peripheral circuit of the existing capacitive touch key system

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Capacitance type touch key system and micro-control unit thereof
  • Capacitance type touch key system and micro-control unit thereof
  • Capacitance type touch key system and micro-control unit thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Apply the existing touch key judgment method, that is, the method based on the absolute value of the equivalent capacitance of the key, to the touch key system provided in the above embodiments. Since this key judgment method is a prior art and has different data processing methods (for example, a Chinese patent application with application number 200810006684.0 discloses an implementation method), therefore, only a brief overview is given here.

[0035] Such as figure 1 and figure 2 As shown, Cx is the equivalent capacitance of the touch button, and forms a switched capacitor circuit with the logic control switches SW1 and SW2. Wherein, the logic control switches SW1 and SW2 can be controlled by the same clock inside the MCU, and they alternately present closed and open states with the same frequency and a fixed time difference. According to the switch capacitance characteristics, the logic control switches SW1 and SW2 and the equivalent capacitance Cx of the touch ...

Embodiment 2

[0044] Similarly, if figure 1 and figure 2 As shown, Cx is the equivalent capacitance of the touch button, and forms a switched capacitor circuit with the logic control switches SW1 and SW2. Wherein, the logic control switches SW1 and SW2 can be controlled by the same clock inside the MCU, and they alternately present closed and open states with the same frequency and a fixed time difference. According to the switch capacitance characteristics, the logic control switches SW1 and SW2 and the equivalent capacitance Cx of the touch key can be equivalent to the resistance Rx. And satisfy:

[0045] Rx=1 / (fs×Cx) (1)

[0046] Wherein fs is the switching frequency of the touch key system, which can periodically switch the logic control switches SW1 and SW2.

[0047] The power supply VDD periodically charges the charging and discharging capacitor 220 through the switch equivalent resistance Rx. Before and after the key is pressed, the change of the equivalent capacitance on the c...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a capacitance type touch key system and a micro-control unit thereof. The capacitance type touch key system comprises a comparer, a switching circuit and a charging time data processing module, wherein the positive input end of the comparer is coupled with a reference signal; the switching circuit comprises a first logic control switch, a second logic control switch and a third logic control switch, wherein the first logic control switch and the second logic control switch alternately present a closed state and a open state under the same frequency, and the third logic control switch is controlled by the output signal of the comparer; the charging time data processing module is connected with the output end of the comparer through signals; and the negative input end of the comparer is coupled with a charge-discharge capacitance end, is coupled with a power supply end through the first logic control switch and the second logic control switch, is coupled with a grounding end through the third logic control switch and is coupled with a plurality of touch key ends through the second logic control switch. The system has the advantages of simple peripheral circuit and low cost of the circuit and solves the problems of large temperature drift, high cost, complicated regulation and the like of the traditional capacitance type touch key system.

Description

technical field [0001] The invention relates to the field of touch button manufacturing, in particular to a capacitive touch button system based on a micro control unit and a micro control unit thereof. Background technique [0002] Touch control can be divided into various control methods such as radio wave type, resistive type, optical type, capacitive type, inductive type and electromagnetic type according to different principles. Each control method has its own advantages and disadvantages and applicable occasions. Among them, the capacitive touch key is suitable for many household appliances due to its relatively simple circuit, which only needs a microprocessor and some peripheral circuits to realize the touch detection and control of the key. [0003] The basic principle of a capacitive touch button is a relaxation oscillator that is continuously charged and discharged. Without touching the switch, the relaxation oscillator has a fixed charge and discharge cycle, an...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H03K17/96
Inventor 荆玉珂许成珅曹中信黄智
Owner SINO WEALTH ELECTRONICS
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com