US3692995A

US3692995A - Arrangement for providing a series of illuminations

Info

Publication number: US3692995A
Application number: US79813A
Authority: US
Inventors: Karl Wagner
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1969-10-16
Filing date: 1970-10-12
Publication date: 1972-09-19
Anticipated expiration: 1989-09-19
Also published as: FR2066032A5; DE1952049A1; CH535528A; GB1326226A

Abstract

Each photoflash bulb, having a high internal resistance before use and a low internal resistance after use, is connected in series with a respective fuse, succeeding photoflash bulbs being connected in parallel with the fuse of the preceding photoflash bulb, or succeeding photoflash bulbs and fuse being connected in parallel with the fuse of the preceding photoflash bulb.

Description

United States Patent Wagner 1 Sept. 19, 1972 [54] ARRANGEMENT FOR PROVIDING A [56] References Cited SERIES OF ILLUMINATIONS UNITED STATES PATENTS [72] lnvenm Wagner Ombrunm Germany 3,532,931 10/1970 Pt Cote et a1. ..431/95 x [73] Assignee: AGFA-Gevaert Aktiengesellschait, 3,562,508 2/1971 Hoffacker ..240/ 1.3 Leverkusen, Germany 2,976,511 3/1961 Lipsitz ..240/ 1.3

[22] Ffled: 1970 Primary Examiner-S. Clement Swisher [21] Appl. No.: 79,813 Att0rney--Michael S. Striker [30] Foreign Application Priority Data [57] ABSTRACT Oct 16 1969 Germany P 19 52 0491 Each photoflash bulb, having a high internal resistance before use and a low internal resistance after use, is 52 us. Cl ..240 1.3 431 95 A in series with a respective fuse succeeding isli Int. Cl. .1...G 03b 15/02 P110)flash bulbs being in Parallel with the 58 F ld Sea h ..240 1.3; 431 95 fuse the Preceding Phmoflash bulb succeeding 1 le 0 rc I photoflash bulbs and fuse being connected in parallel with the fuse of the preceding photoflash bulb.

10 Claims, 2 Drawing Figures ARRANGEMENT FOR PROVIDING A SERIES OF ILLUMINATIONS BACKGROUND OF THE INVENTION The invention relates to an arrangement for providing a series of illuminations, the arrangement comprising a plurality of consecutive photoflash units.

SUMMARY OF THE INVENTION An object of the invention is an arrangement for providing a series of illuminations, the arrangement insuring in a simple manner that the photoflash bulbs are set off in the correct order.

Another object of the invention is the arrangement of the preceding object that is reliable in operation and inexpensive to manufacture.

The invention consists essentially of a plurality of consecutive photoflash units, each including in series fuse means and a photoflash bulb having a high internal resistance before, and a low internal resistance after, flashing, the fuse means opening when the corresponding bulb flashes, and circuit means connecting at least the photoflash bulb of each subsequent photoflash unit in parallel with the fuse means of the preceding photoflash unit.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction'and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a circuit diagram of a first embodiment of the invention; and

FIG. 2 is a circuit diagram of a second embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, a source of current 1 is connected in series with a resistor 2, which is connected to a capacitor 3 that is charged by the source 1. A synchronous switch 4 connects the capacitor 3 to an arrangement 5 for producing a series of illumination, such as photoflashes, for taking pictures. This unit comprises three

photoflash bulbs

6, 7 and 8. Connected in series with each of these bulbs is a

respective fuse

9, 10, or 11. The photoflash bulb 7 and its fuse are connected in parallel with the fuse 9, and the photoflash bulb 8 with its fuse l l is connected in parallel with the fuse 10. The other terminals of the fuses 9, l0 and 11 are connected in common to the positive plate of the capacitor 3. A test switch 12 connects the negative plate of the capacitor 3 to a test lamp .13, the other terminal of which is connected to the junction between the photoflash bulb 8 and its fuse l l.

The arrangement 5 just described operates in the following manner. Upon closing the synchronous switch 4, the capacitor 3, which has been previously charged through the resistor 2, discharges through the photoflash bulb 6 and its fuse 9. The photoflash lamps used have the property that their internal resistance is very high before they are flashed and very low afterwards, owing, for example, to the fact that the electrodes melt together. After the lamp 6 has flashed, the

internal resistance of this lamp is very low. Moreover, the fuse 9 melts in consequence of the heat developed when the lamp 6 flashes, so that the current path of the electrical circuit associated with the lamp 6 is broken. Therefore, the short circuit across the photoflash bulb 7 is interrupted.

When the capacitor 3 has recharged and the synchronous switch 4 is again closed, the capacitor discharges through the burned-out, low-resistance, photoflash bulb 6, and through the photoflash bulb 7 and its fuse 10.

If the user wants to determine whether or not at least the last photoflash bulb 8 is good, he closes the test switch 12. If the bulb 8 is good, the fuse 11 will be intact; and the test lamp 13 will illuminate.

If the synchronous switch 4 is again closed, the capacitor 3 discharges through the two burned-out

photoflash bulbs

6 and 7, and through the good photoflash bulb 8 and its fuse 11.

If the test switch 12 is now closed, the test lamp 13 will not illuminate, because the current path through the fuse 11 is broken. The user of the arrangement therefore knows that all of the photoflash bulbs are used up.

The test lamp 13 can also be connected in parallel with the fuse 11, in which case the lamp lights only if the fuse 11 is open, indicating that the photoflash bulb 8 is burned out. a

The invention insures, in a very simple manner, that once the respective photoflash bulb is used, the current path of the corresponding fuse is interrupted, thereby removing the short circuit across the following series connected photoflash bulb and fuse. Moreover, since the internal resistance of a photoflash bulb is low after flashing, the following bulb can be flashed by pressing the synchronous switch. A further advantage of the invention is that the flash bulbs used have only two connections and are simply designed, enabling the bulbs to be manufactured inexpensively. Another advantage of the invention is that the arrangement 5 has no switching contacts, since the individual components are always conductively connected together.

With reference to the embodiment shown in FIG. 2, a source of current 14 is connected in series to a resistor 15, which latter is connected to a capacitor 16 charged by the source 14. The junction between the resistor l5 and the negative plate of the capacitor 16 is connected to a synchronous switch 17. The arrangement 18 for producing a series of illuminations comprises four

photoflash bulbs

19,20,21 and 22, which are series connected with

respective fuses

23,24,25 and 26. The photoflash bulb 20 is shunted across the fuse 23, the bulb 21 across the fuse 24, and the bulb 22 across the fuse 25. All of their parallel circuits, each comprised of a photoflash bulb and the fuse of the preceding photoflash bulb, together form a series circuit.

Connected parallel to the fuse 26 of the last photoflash bulb 22 is a test circuit, composed of a test voltage source 27, a test switch 28, and a test lamp 29, all connected in series.

The embodiment described operates in the following manner. The capacitor 16 is charged through the resistor to the full voltage of the source 14. When the switch 17 is closed, the capacitor 16 discharges through the photoflash bulb l9, and through the

fuses

23,24 and 25. The

bulbs

20, 21 and 22 do not flash, because they are shunted by the

respective fuses

23,24 and 25. The heat developed by the flash of the bulb 19 melts the fuse 23, so that the short across the bulb is interrupted. The internal resistance of the used bulb 19 is low.

Once the capacitor 16 has been recharged to the full voltage of the source 14, the synchronous switch 17 can again be closed. If the switch 17 is closed, the capacitor 16 discharges through the used, low resistance, bulb 19, and through the high resistance bulb 20, as well as through the

fuses

24 and 25. After the bulb 20 has flashed, the fuse 24 is melted; and the short across the bulb 21 is broken.

If the test switch 28 is closed, the test lamp 29 will illuminate, because the current path through the fuse 26 is still closed.

Closing the synchronous switch 17 again, causes the capacitor 16 to discharge through the used, low resistance,

bulbs

19 and 20, and through the unused, relatively high resistance, bulb 21 and through the fuse 25. After bulb 21 is flashed, the fuse 25 is open; and the bulb 22 is ready to be flashed. If the synchronous switch 17 is again closed, the bulb 22 flashes; and the fuse 26 melts, opening the current path of the test circuit. Now, the test lamp does not illuminate when the test switch 28 is closed, so that the user knows that all of the flash bulbs are used up.

The test lamp 29 can also be connected in parallel with the source 27 and the fuse 26. In this embodiment, the lamp 29 lights only if the fuse 26 is open, thereby indicating that all of the bulbs have been used.

In accordance with the invention, the fuses can be either an integral part of the photoflash bulbs, or a component positioned outside of, and sufficiently near to, the respective flash bulbs so that the corresponding fuse melts when the bulb flashes.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of circuits differing from the types described above.

While the invention has been illustrated and described as embodied in arrangement for providing a series of illuminations, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended 1. In an arrangement for producing aseries of illuminations comprising, in combination, a plurality of consecutive photoflash units, each including in series fuse means and a photoflash bulb having a high internal resistance before, and a low internal resistance after flashing, said fuse means opening when the corresponding bulb flashes; and circuit means connecting the photoflash bulb of each subsequent photoflash unit in parallel with the fuse means of the preceding unit, and connecting said fuse means of all said units in series with each other.

2. In an arrangement as defined in claim 1, further comprising current source means, one pole of which is connected directly to the junction point between the fuse means and the photoflash bulb forming the last unit in the series, and the other pole of which is connectable to the photoflash bulb forming part of the first unit in the series at its terminal remote from the junction point between the latter photoflash bulb and its associated series fuse means. I

3. In an arrangement as defined in claim 1, wherein the photoflash bulbs of said units are connected in serles.

4. In an arrangement as defined in claim 3, wherein the fuses of all said units but the last are connected in series.

5. In an arrangement as defined in claim 1, including a test circuit for determining whether there are any unused photoflash bulbs, and a switch for connecting said test circuit to the last of said photoflash units.

6. In an arrangement as defined in claim 1, wherein said fuse means is an integral part of each said photoflash bulb.

7. In an arrangement as defined in claim 1, wherein each said fuse means is located in the immediate vicinity of a respective said photoflash bulb, so that the heat of the bulb melts and opens the respective fuse means.

8. In an arrangement as defined in claim 1, wherein said photoflash units form an integral structure.

9. In an arrangement for producing a series of illuminations, in combination, a plurality of consecutive photoflash units, each including in series fuse means and a photoflash bulb having a high internal resistance before, and a low internal resistance after flashing, said fuse means opening when the corresponding said bulb flashes; circuit means connecting at least the photoflash bulb of each subsequent photoflash unit in parallel with the fuse means of the preceding photoflash unit; a test circuit for determining whether there are any unused photoflash bulbs; and a switch for connecting said test circuit to the last of said photoflash units, said test circuit including a lamp connected to said fuse means of the last of said photoflash units to indicate, when said switch is closed, whether said fuse means is open or closed, and further including current source means for energizing said lamp.

10. In an arrangement for producing a series of illuminations, in combination, a plurality of consecutive photoflash units, each including in series fuse means and a photoflash bulb having a high internal resistance before, and a low internal resistance after flashing, said fuse means opening when the corresponding said bulb flashes; circuit means connecting at least the photoflash bulb of each subsequent photoflash unit in parallel with the fuse means of the preceding photoflash unit; a test circuit for determining whether there are any unused photoflash bulbs; and a switch for connecting said test circuit to the last of said photoflash units including a source of electric current, and

wherein the photoflash bulb of the last of said units has one side directly connected to one pole of said source.

Claims

1. In an arrangement for producing a series of illuminations comprising, in combination, a plurality of consecutive photoflash units, each including in series fuse means and a photoflash bulb having a high internal resistance before, and a low internal resistance after flashing, said fuse means opening when the corresponding bulb flashes; and circuit means connecting the photoflash bulb of each subsequent photoflash unit in parallel with the fuse means of the preceding unit, and connecting said fuse means of all said units in series with each other.

2. In an arrangement as defined in claim 1, further comprising current source means, one pole of which is connected directly to the junction point between the fuse means and the photoflash bulb forming the last unit in the series, and the other pole of which is connectable to the photoflash bulb forming part of the first unit in the series at its terminal remote from the junction point between the latter photoflash bulb and its associated series fuse means.

3. In an arrangement as defined in claim 1, wherein the photoflash bulbs of said units are connected in series.

10. In an arrangement for producing a series of illuminations, in combination, a plurality of consecutive photoflash units, each including in series fuse means and a photoflash bulb having a high internal resistance before, and a low internal resistance after flashing, said fuse means opening when the corresponding said bulb flashes; circuit means connecting at least the photoflash bulb of each subsequent photoflash unit in parallel with the fuse means of the preceding photoflash unit; a test circuit for determining whether there are any unused photoflash bulbs; and a switch for connecting said test circuit to the last of said photoflash units including a source of electric current, and wherein the photoflash bulb of the last of said units has one side directly connected to one pole of said source.