US3648103A

US3648103A - Device for indicating interruption of electrical service

Info

Publication number: US3648103A
Application number: US25626A
Authority: US
Inventors: Takaaki Okada
Original assignee: Nidec Copal Corp
Current assignee: Koparu KK; Nidec Precision Corp
Priority date: 1970-04-06
Filing date: 1970-04-06
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A diode, a resistor, and a capacitor are connected in series between power input terminals, and a neon lamp is connected in parallel with said capacitor through contact points controlled by an electromagnetic relay. Using such an arrangement, upon the resumption of electrical service after its interruption, the neon lamp automatically flickers at a predetermined cycle rate.

Description

llnited States Patent Ulmda Mar. 7, 11972 [54] DEVHCE FOR INDICATING [56] References Cited INTERR PTION F ELECTRI AL SERVHZS 0 C UNITED STATES PATENTS 2,513,396 7/1950 Beck ..3l5/l32 X m] Invent okada Japan 3,022,498 2/1962 Alcott... ..331/131 x [7 3] Assignee: Kabushiki Kaisha Koparu [22 Filed: Apr. 6 1970 Primary Examiner-Raymond F. HOSSffllCl [21] A l N 25 626 Attorney-Otto John Munz [57] ABSTRACT [52] U.S.Cl ..3l5/136, 3l5/l35gjgllz/slgk A diode, a resistor and a capacitor are connected in Series [51] Int Cl Gosh 21/00 between power input terminals, and a neon lamp is connected [58] Field 5137156 1231 50 131 132 in Parallel with said capacim thmugh Pims 5/133 35 13 331/131; 340/253 R 253 B, 253 trolled by an electromagnetic relay. Using SUCh an arrange- Q, 25 ment, upon the resumption of electrical service after its interruption, the neon lamp automatically flickers at a predetermined cycle rate.

6 Claims, 2 Drawing Figures Patented March 7, 1972 3,648,103

FIG. 2

INVENTOR TAKAAK I OKADA DEVICE FOR INDICATING INTERRUPTION OF ELECTRICAL SERVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for warning of the interruption of an electrical service current, and more particularly to a device for indicating the interruption of electrical service which is capable of informing the user of the last interruption of service by the flickering of a neon lamp which occurs upon the resumption of the service.

2. Description of the Prior Art Today, a device of a kind as described herein for indicating interruption of electrical service is used with electrical machines and apparatus such as an electric clock which is affected even by a very short interruption of the service. Such a device facilitates readjustment of time by the warning of the need therefor. However, in a conventional device, information on service interruption has been provided merely through a color indication, that is, through colors painted on the edge of an indicating member which is connected to an armature controlled by an electromagnet. Conventional devices of this type were disadvantageous in that they required a large electric current to maintain such an indicating member in position, and further such devices merely relying on the color indication had the drawback that the user frequently failed to become aware of the interrupted service.

SUMMARY OF THE INVENTION It is, therefore, a general object of the present invention to provide a device for indicating interruption of electrical service wherein an electromagnetic relay is used to form, upon the resumption of service following the last interruption, a relaxation oscillation circuit which includes a neon lamp or a discharge tube, whereby this neon lamp or discharge tube is caused to flicker so that the user of the service is given a strong visual warning as to the last interruption of the electrical service.

Another object of the present invention is to provide a device for indicating interruption of service which is provided with an electrical circuit arrangement adapted to overcome or minimize the characteristic deterioration of a capacitor included in the relaxation oscillation circuit.

A further object of the present invention is to provide a device for indicating interruption of service which is provided with a circuit arrangement enabling the device to be used both on AC and DC service lines.

Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments and claims in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, the letter M generally represents an electromagnetic relay. This electromagnetic relay M comprises a core 1, a magnet coil n, stationary contact points P, and P and movable contact points P and P The stationary contact point P, is mounted on a conductive member P,, which is fixed to a stationary connection terminal P The stationary contact point P, is mounted on a conductive member P which is fixed to a stationary connection terminal P The movable contact points P and P are mounted on one end of a contact plate member P or a spring member consisting of, for example, a phospherbronze plate. The other end of the contact plate member P is fixed to a stationary connection terminal P On one side of the contact plate member P,,,, a contact piece P of magnetic material is mounted. Ordinarily the contact points P, and P are closed and thus the contact points P, and P, are spaced from each other in a released position.

The electromagnetic relay M has a force of attraction only sufficient to hold the movable contact point P in the held position, i.e., the position wherein the contact points P, and P are brought into contact, by the aid of a temporary depression exerted on the contact plate member P towards the magnet coil 1. That is, when a magnetizing current flows through the magnet coil n, the core 1 generates a magnetic force of attraction which, however, is not strong enough to attract the contact plate member P to the extent that the movable contact point P is brought into contact with the contact point P,. However, when the contact plate member P is resiliently bent by manual pressure and thus the contact points P, and P are brought into contact, the magnetic force of attraction generated by the core 1 is sufficient to retain the contact points P, and P in their contacted state even after the manual pressure has been released.

When an AC service voltage is applied between input terminals a-a', the contact plate member P needs only to be manually depressed once so as to bring the movable contact point P into contact with the contact point P, and this state of contact remains as described above. Thus, during the initial service period, an AC service voltage applied between the input terminals a-a' causes current to flow to a neon lamp NL across a steady resistor R, and the neon lamp NL is lit with uniform intensity. The lighting of the neon lamp signifies that the initial service is being continued. During this period, the neon lamp NL serves as a pilot lamp indicating an uninterrupted service. However, if there is no necessity to indicate that the initial service is being continued, the steady resistor R, and the contact point P, may both be eliminated. It is to be noted that during the initial service period, a capacitor C is charged through a diode D and a timing resistor R but this charging has no afiect on the neon lamp NL.

Now, when service is interrupted and thus AC voltage is not applied between the input terminals a-a', the neon lamp NL is extinguished as a matter of course. The fact that the neon lamp NL is off signifies that service is being interrupted. During this period of interruption, the core 1 of the electromagnetic relay M has no magnetic force of attraction so that the movable contact point P is not in contact with the contact point P, but instead the movable contact point P, is in contact with the contact point P Thus the neon lamp NL is connected in parallel with the capacitor C.

Next, when AC voltage is reapplied between the input terminals aa' upon the resumption of service, the capacitor C is charged through the diode D and the timing resistor R, constituting a timing circuit. At the point when the terminal voltage of the capacitor C reaches the breakdown voltage of the neon lamp NL, discharge is struck and the lamp is lit. As a consequence of this discharge, the voltage of capacitor C drops to the extinction voltage and thus the neon lamp NL stops discharging and extinguishes. This results in the resumption of charging of the capacitor C through the resistor R and in this manner the neon lamp NL resumes luminiscing with a predetermined cycle by time constant R C. It is because of this behavior of luminiscing which continues at a cycle that the neon lamp NL keeps on flickering. This flickering of the neon lamp NL indicates the resumption of service after its interruption.

In FIG. 2, another embodiment of the present invention is illustrated. The circuit shown therein is different from that according to FIG. I in the following two points: l the capacitor C and the neon lamp NL are replaced by each other, and (2) both the resistor R, and the contact point P, are eliminated.

In the circuit as shown in FIG. 2, the capacitor C is out of the circuit during the initial service period (normally a long period), during which the movable contact point P and the stationary contact point P are out of contact. Therefore, it is possible to minimize the characteristic deterioration of the capacitor. During the initial service period, the neon lamp NL is lit, with the resistor R functioning as a steady resistor. That is, the function of the resistor R,, in FIG. 1 is now achieved by the resistor R The resistor R in FIG. 2 is an element which, together with the capacitor C, determines the flickering cycles per second of the neon lamp NL. In determining the value of such an element, the resistor R is first selected so that its value is adapted to a steady resistor of the neon lamp NL and then the capacitor C is selected in such a way that time constant R C comes to a desired value.

In the circuits of FIGS. 1 and 2, which have hereinabove been described, the electromagnetic relay is directly connected between the input terminals. However, when the electromagnetic relay requires a DC magnetizing current, DC current passing through the diode D may be used for this current. In case the area at which the present device is used happens to be that of a DC service area, the DC voltage is directly applied between the input terminals aa' and in such a case the diode D is unnecessary.

While only preferred embodiments of the device according to the invention have been shown and described, it will be understood that many modifications and changes can be made within the scope of the invention.

I claim:

1. A device for indicating interruption of electrical service comprising: a branch circuit having a timing resistor and a capacitor in series and connected between input terminals,

an electromagnetic relay having a magnet coil connected between said input terminals and having a contact point means including a contact point movable between a first released position and a second held position, said electromagnetic relay having a force of attraction only sufficient to hold said movable contact point in the held position, and

a discharge tube connected in parallel with said capacitor through said contact point means,

whereby said discharge tube is capable of flickering upon the resumption of the service after its interruption.

2. A device according to claim 1, in which a rectifier is connected between one of said input terminals and said timing resistor.

3. A device according to claim 1, in which said contact point means includes a first stationary contact point, a second stationary contact point and a third movable contact point, said first contact point being connected to one of the said input terminals through a steady resistor, said second stationary contact point being connected to one of the terminals of said capacitor, and said third contact point being connected to one of the terminals of the discharge tube, the discharge tube being a neon lamp.

4. A device according to claim 3, in which a rectifier is connected between one of said input terminals and said timing resistor.

5. A device for indicating interruption of an electrical service comprising: a branch circuit having a timing resistor and a discharge tube in series and connected between input terminals,

a capacitor connected in parallel with said discharge tube through said contact means,

6. A device according to claim 5, in which a rectifier is connected between one of said input terminals and said timing resistor.

Claims

1. A device for indicating interruption of electrical service comprising: a branch circuit having a timing resistor and a capacitor in series and connected between input terminals, an electromagnetic relay having a magnet coil connected between said input terminals and having a contact point means including a contact point movable between a first released position and a second held position, said electromagnetic relay having a force of attraction only sufficient to hold said movable contact point in the held position, and a discharge tube connected in parallel with said capacitor through said contact point means, whereby said discharge tube is capable of flickering upon the resumption of the service after its interruption.

5. A device for indicating interruption of an electrical service comprising: a branch circuit having a timing resistor and a discharge tube in series and connected between input terminals, an electromagnetic relay having a magnet coil connected between said input terminals and having a contact point means including a contact point movable between a first released position and a second held position, said electromagnetic relay having a force of attraction only sufficient to hold said movable contact point in the held position, and a capacitor connected in parallel with said discharge tube through said contact means, whereby said discharge tube is capable of flickering upon the resumption of the service after its interruption.