JPS5819663Y2 - Theft alarm circuit for vending machines, etc. - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a theft alarm circuit for a vending machine, a bill or coin exchange machine, etc.

Conventional theft alarm circuits of this type have a button that sounds an alarm device, such as an alarm buzzer, when the power cord is pulled out or disconnected. It was impossible to determine whether there was a power outage or not, and when the power went out, the buzzer would go off even though there was no theft, causing problems with noise.

In view of the above points, the present invention aims to distinguish between theft and a power outage, and to prevent an alarm device from operating in the event of a power outage.

An embodiment of the present invention will be described below in detail based on the drawings.

Reference numeral 1 denotes a normal AC power cord plug, which supplies power to a control circuit of a necessary device 7 such as an automatic money changer or vending machine, and also energizes a coil 3a of a first alarm relay 3.

Reference numeral 2 denotes an AC power cord plug that energizes the coil 4a of the second alarm relay 4.

Reference numeral 5 denotes an alarm device, such as an alarm buzzer, one end of which is connected to the battery 6, and the other end connected to the common terminal of the switch 4b of the second alarm relay 4.

The NC contact of the switch 4b is connected to the No contact of the switch 3b of the first alarm relay 3, and the No contact is also connected to the NC contact of the switch 3b.

And the common terminal of switch 3b is the reset switch 8
It is connected to the battery 6 via.

A holding relay 9 forms a self-holding circuit for the alarm buzzer 5 once energized.

- The reset switch 8 releases the self-holding state of the holding relay 9.

Next, the operation of the above configuration will be explained below.

When the power cord plugs 1 and 2 are now plugged into the power source, the first alarm relay 3 and the second alarm relay 4 are in an energized state, and the switches 3b and 4b are both in the No contact.

In this state, if the plug 1 is pulled out from the power source or the cord is cut by mischief, the first alarm relay 3
Since the switch 3b is demagnetized, the switch 3b is replaced with an NC contact, so power from the battery 6 is supplied to the alarm buzzer 5, and the buzzer sounds.

Similarly, when the power coat plug 2 is pulled out or its cord is cut, the second alarm relay 4 is demagnetized and the alarm buzzer 5 sounds.

That is, if one of the power cord plugs 1 and 2 is pulled out from the power source or the cord is cut, the buzzer 5
sounds.

At the same time that the buzzer 5 sounds, the holding relay 9 connected in parallel with the buzzer 5 is energized and holds itself via the No contact of its own switch 9b, so the buzzer 5 does not open the reset switch 8. It will continue to ring as long as it does not.

Therefore, even if one of the power cord plugs 1 and 2 that have not been pulled out is pulled out, that is, even if both are pulled out, the alarm buzzer will still be activated.
5 will continue to ring.

In the event of a power outage, the power to the power cord plug 1゜2 is cut off at the same time, so the first and second alarm relays 3 and 4
Since the switches 3b and 4b are both changed to NC contacts at the same time, the alarm buzzer 5 does not sound.

As described above, the present invention takes advantage of the fact that when a power cord plug is pulled out or disconnected from the power source, one of the two plugs is always plugged in first, and it is possible to determine whether it is theft or a power outage. The alarm device is activated when it is determined that the vehicle has been stolen, but not activated in the event of a power outage.

Therefore, there is no possibility that the alarm device is activated even in the event of a power outage as in the conventional case, and theft can be determined reliably.

[Brief explanation of drawings]

The figure is an electrical circuit diagram showing an embodiment of the present invention. 3...First alarm relay, 4...Second alarm relay 5...Alarm buzzer, 6...Battery 8...Reset switch, 9...Holding relay.

Claims (1)

[Scope of utility model registration request] A first alarm relay is energized when power is supplied through a first power cord plug that supplies power to a required device such as a vending machine, and power is supplied through a second power cord plug. a second alarm relay that is energized when
or an alarm device that is activated by battery power when either of the second alarm relays is demagnetized first, and a holding relay that has a coil connected in parallel with the alarm device and holds itself through its own contacts; A theft alarm circuit for a vending machine, etc., which is equipped with a reset switch that releases the self-holding of the holding relay.