KR19990019804A - Anti-theft circuit - Google Patents

Abstract

The present invention relates to an anti-theft circuit that can detect the start key operation of the vehicle to prevent theft of the vehicle by emitting an alarm sound in an emergency, and checks the time from the key insertion until the normal key rotation is performed. If this time limit is exceeded, an alarm will sound as an emergency situation to prevent theft of the vehicle.

The present invention provides a key switch 51 for detecting a start key insertion of a vehicle, a first relay 53 operated in conjunction with the key switch 51, a rotary switch 52 for detecting rotation of a start key, and A timer 54 for counting the time from the key switch 51 to the rotary switch 52 and the second switch operated when the rotary switch 52 is not operated for a predetermined time or more. It is characterized by consisting of a relay 55, a horn 56 which is operated by the second relay 55 to generate an alarm sound.

The anti-theft circuit of the present invention can be used not only for theft prevention of a vehicle but also for theft prevention in each home, and can be applied to any product using a key.

Description

Anti-theft circuit

The present invention relates to an anti-theft system that can prevent theft of the vehicle, and relates to an anti-theft circuit that can prevent theft of the vehicle by detecting a start key operation of the vehicle to sound an alarm in an emergency.

The start switch of the vehicle is operated by inserting and turning the start key to start the electric device and the engine. Therefore, when a key or foreign matter other than the normal key is inserted into the key groove of the starting key box and rotated, the vehicle recognizes it as a normal starting and the vehicle may be stolen.

However, if the lock is not a normal key in any lock, it takes a considerable amount of time to insert and later unlock the key, and thus, the anti-theft device can be configured without using a separate device.

The present invention has been made to solve the above-mentioned problems of the prior art, checks the time from the key insertion until the normal rotation of the key and if the time exceeds the prescribed time, the alarm is considered as an emergency situation and sounds an alarm. The purpose is to provide an anti-theft circuit that can prevent theft of the vehicle.

1 is a block diagram showing an anti-theft circuit of the present invention,

2 is an operational state diagram of a key switch which is a main configuration of the present invention,

3 is an operational state diagram of a rotary switch which is a main component of the present invention.

* Explanation of symbols for the main parts of the drawings

51: key switch 51a: A contact button

51b: ignition key 51c: key groove

52: rotary switch 52a: B contact button

52b: rocker 53: first relay

54 Timer 55 Second Relay

56: horn

The present invention provides a key switch for detecting a vehicle's ignition key insertion, a first relay operated in conjunction with the key switch, a rotary switch for detecting rotation of a ignition key, and the rotary switch after the key switch is operated. And a timer for counting the time until it is activated, a second relay operated when the rotary switch is not operated for more than a predetermined time, and a horn operated by the second relay to generate an alarm sound.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the anti-theft circuit of the present invention includes a key switch 51 that detects a vehicle's ignition key insertion, a first relay 53 operated in conjunction with the key switch 51, and a ignition key. Rotary switch 52 for detecting the rotation of the timer, a timer 54 for counting the time from the operation of the key switch 51 until the rotary switch 52 is operated, and the rotary switch for more than a predetermined time ( 52 is composed of a second relay 55 which is operated when not in operation, and a horn 56 which is operated by the second relay 55 to generate an alarm sound.

Here, the key switch 51 is a push button switch of the A contact which is turned on only when the ignition key 51b is inserted as shown in FIG. 2, and the rotary switch 52 is shown in FIG. 3. It is a push button switch of the B contact which is turned off only when the ignition key 51b is inserted and rotated. In addition, the second relay 55 is set to be turned off by the timer 54 when a predetermined time elapses.

The anti-theft circuit of the present invention configured as described above inserts a key into the key groove and prevents theft of the vehicle by sounding an alarm if it does not operate normally for a predetermined time.

When the starter key 51b is inserted into the key groove 51c, the key switch 51 is turned on to operate the first relay 53. At this time, since the rotary switch 52 is in the ON state, power is supplied to the timer 54 to start counting. When the starter key 51b is rotated, the rotary switch 52 is turned off, so that the operation of the timer 54 is stopped, and the engine enters a normal start state.

In this case, as shown in FIG. 2, since the button 51a protruding from the key groove 51c is advanced by inserting the ignition key 51b, the key switch 51 connects both terminals of the switch. In the case of the rotary switch 52, the button 52a pressed by the rocker 52b rotated together with the start key 51b after insertion of the start key 51b is locked by the rocker 52b. Blocks both terminals protruding along the rotation.

If the rotary switch 52 is not turned off while the ignition key 51b is inserted into the key groove 51c, and the predetermined time has elapsed, the second relay 55 is operated by the timer 54 that counts it. The power is applied to the horn 56 by the second relay 55 to sound an alarm.

That is, when a person who steals the vehicle inserts a foreign object which is not a normal key and attempts to start the vehicle, the key switch 51 is turned on according to the insertion of the foreign substance so that the first relay 53 is operated. However, since the rocker 52b is not easily rotated by the foreign matter, and thus the rotary switch 52 is not turned off and remains on, the second relay 55 is operated after a predetermined time and the horn 56 is turned on. Power is applied to the alarm to sound.

Therefore, the thief is surprised by the alarm sound, and the owner of the car can hear the alarm sound and jump out, thereby preventing theft of the vehicle.

Here, the key switch and the rotary switch may be installed in the door key box as well as the start key box into which the start key is inserted, and additional control may be performed by installing a separate key box.

As described above, the anti-theft circuit of the present invention has an advantage of preventing theft in advance because an alarm sounds when a certain time elapses when the key box is to be unlocked by using a foreign object rather than a normal key.

In addition, the anti-theft circuit of the present invention can be used for theft prevention in each home as well as to prevent theft of the vehicle, there is another advantage that can be applied to any product using the key.

Claims (8)

A key switch for detecting the insertion of a start key of the vehicle, a first relay operated in conjunction with the key switch, a rotary switch for detecting rotation of the start key, and when the rotary switch is operated after the key switch is operated. The anti-theft circuit which consists of a timer which counts the time to a time, the 2nd relay which is operated when a rotary switch is not operated more than a prescribed time, and the horn which is operated by the said 2nd relay and produces an alarm sound. The anti-theft circuit according to claim 1, wherein the key switch is a push button switch of an A contact which is turned on only when a key is inserted. The anti-theft circuit according to claim 1, wherein the rotary switch is a push button switch of a contact B which is turned off only when a key is inserted and rotated. The anti-theft circuit according to claim 1, wherein the second relay is set to be turned off by a timer when a predetermined time elapses. The anti-theft circuit according to claim 1, wherein the key switch and the rotary switch are installed in a start key box. The anti-theft circuit according to claim 1, wherein the key switch and the rotary switch are installed in a door key box. The anti-theft circuit according to claim 1, wherein the key switch and the rotary switch are additionally installed on one side of the vehicle separately from the start key box or the door key box. The anti-theft circuit according to claim 1, wherein the key switch and the rotary switch are installed in a home door.