GB2203789A - Touch-control anti-burglar circuit - Google Patents

Abstract

A touch-controlled confidential number anti-burglar circuit comprises a touch entry plate 11 feeding signals to an entry unit 1, a counter unit 3, a lock unit 5, an error-detecting unit 6 and an alarm unit 7, wherein the counter unit 1 counts the number of touches on the plate 11 by the user and transmits a corresponding signal to the lock unit 5 or the error-detecting unit 6 to trigger the opening of a door or the sounding of an alarm. A reset unit 4 resets the counter unit 2 and clears the lock unit 5 and error-detecting unit 6 after use to ready them for next use. <IMAGE>

Description

TITLE: TOUCH-CONTROL ANTI-BURGLAR CIRCUIT This invention relates to a touch-controlled antiburglar circuit comprising an entry unit to sense the number of contacts (touches) on a plate so as to open a door if the number of touches by the user corresponds to a pre-determined confidential number or to sound a noticeable alarm if the number does not correspond.

The anti-burglar system according to this invention therefore saves the user from the inconvenience of having to carry a key and provides better protection against burglars.

SUMMARY A primary object of this invention is to provide a touch-controlled anti-burglar circuit which compares the number of touches entered by the user with a predetermined confidential number to determine whether to open the door or to sound an alarm signal.

Further objects and advantages of the present invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention be pointed out with particularity in the claims annexed to and forming a part of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow diagram of the anti-burglar circuit in accordance with this invention; and FIG. 2 is a detailed circuit diagram of this invention.

DETAILED DESCRIPTION OF THE INVENTION Now referring to FIG. 1, it can be seen that the touch-controlled confidential number anti-burglar circuit of the present invention comprises an entry unit 1, a delay unit 2, a counter unit 3, a reset unit 4, a locking unit 5, an error-detecting unit 6 and an alarm unit 7. The delay unit 2 provides a delay time after the power is ON. The entry unit 1 has an entry plate 11 which is pressed by the user. Each time the user presses the plate 11, a signal is received by the counter unit 3. If the number of signals received by the counter unit 3 corresponds to a preset confidential number, then the locking unit 5 will cause the door to open; if the number of signals does not correspond (i.e. equal), then the error-detecting unit 6 will then trigger the alarm unit 7 to sound an alarm.The reset unit 4 resets the counter 2 and clears the locking and error-detecting units 5 and 6 after one entry sequence so as to prepare for the next entry sequence.

Referring to FIG. 2, a detailed circuit diagram of this invention can be seen. The entry circuit comprises a Hartley oscillator 12 and a direct current amplifier (comprising transistors 13 and 14). The entry plate 11 connects to the Hartley oscillator when no entries are input. The Hartley oscillator oscillates continually and its output is filtered through a diode D1 and turns transistor 13 ON and transistor 14 OFF. When transistor 14 is OFF, no signal is input to the counter unit 3, and the counter unit 3 is non-activated. Once the input has been entered (i.e. the entry plate has been pressed), the quiescent operating condition of the transistor Q1 of the Hartley oscillator 12 is changed so that the Hartley oscillator 12 stops oscillating. In the meantime, transistor 13 is OFF, but transistor 14 is ON.Therefore, the output of transistor 14 inputs to the input terminal of the counter IC 31 of the counter unit to make the counter unit 3 start to count.

Note that before anti-burglar circuit of this invention starts to operate, there will be a delay period of about 1 minute. This delay period is generated by the delay unit 2. The delay unit 2 comprises a capacitor 23 and a resistor 22, which forms a differential circuit, an inverter 21 and a diode 24.

When the power is ON, the differential circuit generates a suddenly rising high voltage which transverses to a low voltage via the inverter G1 and inputs to disenable the counter unit 3. After a time (the constanttime interval is decided by the product of the value of capacitor 23 and the value of resistor 22), the voltage level of the differential circuit falls to LOW and the input voltage of the counter unit 5 rises to HIGH so that the counter unit 3 is enabled and starts to count.

The counter unit 3 comprises a decimal counter IC 31 to which the 1 - 9 output terminals are respectively connected to a selected switch 32 by means of a diode 33. Each of the selected switches 32 has two selection terminals, one of which connects to the locking unit 5 and the other of which connects to the error-detecting unit 6. For example, in FIG. 2, the selected switch of the third output terminal connects to the locking unit 5 (HIGH state) but the others connect to the errordetecting unit 6 (on LOW state); therefore, if the number of touches counted by the counter IC 31 is 3, a signal with high voltage inputs to the locking unit 5 and is charged by the capacitor 53. Further, the signal inputs to an inverter 51 and outputs to allow the door to be opened.When the charged voltage of the signal reaches the high threshold voltage of the inverter 51 (the charging time is the product of the capacitor 53 value and the resistor 52 value), the output of the inverter G2 is at LOW state and the low voltage signal feeds back via a diode 55 to the input terminal of the counter IC 31 to disenable the input terminal. That is, during the constant time interval (the product of the capacitor 53 value and the resistor 52 value), the entry plate 11 should be entered with the predetermined confidential number (such as 3 in the above example), otherwise any entries will not be received by the counter IC 31 over the constant time interval.

Therefore, if the entry number (i.e. number of touches) counted by the counter IC 31 is not correspondentRto the predetermined confidential number, any output signal with high voltage of the counter IC 31 inputs to the error-detecting circuit 6 and is charged by the capacitor 64. Once the signal is charged to reach the threshold high voltage of the inverter 61 (the constant time interval is the product of the resistor 63 and the capacitor 64), the output of the inverter 62 via the inverter 61 is at HIGH state, thereby triggering the alarm unit 7 to sound.

Additionally, the low output of the inverter 61 feeds back via a diode 66 to disenable the input terminal of the counter IC 31. Therefore, as mentioned above, when the fixed time period is exceeded, an entry can not stop the alarm from sounding.

The alarm unit 7 comprises a rectangular-wave oscillator composed of two NAND gates 71, 72 (which receive the signal from the error-detecting unit 6) transmits a pulse wave to the Darlington circuit (composed of the transistors 75 and 76) to trigger an alarm inverter 41, then the output voltage of the inverter 41 -is turned to HIGH and the high voltage signal is input to the RESET pin of the counter IC 31 via a capacitor 45. Therefore, all the output terminals of the counter IC 31 are reset to LOW and the alarm stops sounding so as to be prepared for the next state. Further, the HIGH signal is turned to LOW via an inverter 42 so that the capacitor 53 of the locking unit 5 and the' capacitor 64 of the error-detecting unit 6 discharge via diode 54 and diode 65, respectively, for preparing for the next state.

From the specification described above, it is obvious that the touch-controlled confidential number anti-burglar circuit of this invention utilizes a number of touches by the user in relation to a pre-set confidential number to form the basis of an anti burglar system.

While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such embodiments as fall within the scope of the appended claims.

Claims (6)

I claim

1/. A touch-controlled confidential number anti-burglar circuit which utilizes a number of touches as a confidential number to control the opening of a door or a window, comprising: an entry unit, a delay unit, a counter unit, a reset unit, a locking unit, an errordetecting unit and an alarm unit, wherein said entry unit connects an entry plate and said entry unit's output state is affected by the entry states of said entry plate; said counter unit counting a number of touches on said entry plate; said locking unit being activated to open the door or a window if a correct number of touches is entered by a user; said error-detecting unit being activated to trigger said alarm unit to sound if an incorrect number of touches is entered by said user; said reset unit resetting said counter unit and clearing said locking and errordetecting units for preparing for a next state after sounding said alarm unit.

2/. A touch-controlled confidential number anti-burglar circuit, as claimed in claim 1, wherein said entry unit comprises a Hartley oscillation circuit and a transistor amplifier circuit; said Hartley oscillator normally oscillating before any touches are entered; the oscillator stopping its oscillation and the output of said amplifier circuit connected to a input pin of said counter unit being HIGH when any touches are entered.

3/. A touch-controlled confidential number anti-burglar circuit, as claimed in claim 1, wherein said counter unit comprises a decimal counter IC, a plurality of diodes and select switches; said counter IC counting the number of touches and the output terminals thereof connecting said locking unit and said error-detecting unit by means of said select switches via said diodes.

4/. As claimed in claim 1, wherein each of said locking units and said error-detecting units comprises an RC integral delay circuit and an inverter; said inverter comprising a diode forming a feedback circuit so that a signal received from said counter unit is fed back to the input terminal of said counter unit; said RC integral delay circuit defining a constant time interval for receiving a number of touches and over the constant time interval, the input terminal of said counter unit being masked; said error-detecting unit further comprising an inverter which turns a LOW signal to a HIGH signal to trigger said alarm unit.

5/. A touch-controlled confidential number anti-burglar circuit as claimed in claim 1, wherein said reset unit comprises an RC delay circuit and an inverters; said RC delay circuit being connected between the output terminal of said entry unit and the input terminal of said inverter; said inverter further connecting said locking unit and said error-detecting unit via another inverter; said reset unit resetting the output terminals of said counter IC to be LOW and clearing said locking unit and said error-detecting unit for preparing for a next state.

6. A touch-controlled confidential numbered anti-burglary circuit as hereinbefore described with reference to the accompanying drawings.