JP2002164231A - Trigger coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trigger coil that can prevent discontinuity in secondary winding. SOLUTION: In a common terminal 14, one end 11a of primary winding 11 is connected to an outlet section 14a, at a side connected to a circuit board. Also, in the common terminal 14, one end 12a of the secondary winding 12 is connected to an outlet section 14b at a side apart from the circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a trigger coil for generating a trigger voltage applied to a trigger electrode of a flash tube.

[0002]

2. Description of the Related Art Conventionally, there has been known a camera for taking a picture by emitting a flash light in synchronization with a shutter operation when the luminance of a subject is insufficient. Such a camera is provided with a flash generation circuit for emitting flash light. The flash generation circuit includes a booster circuit, a main capacitor that stores the power boosted by the booster circuit, a flash arc tube that emits a flash by the power released from the main capacitor, and a trigger electrode of the flash arc tube. And a trigger coil for generating a trigger voltage to be applied.

The trigger coil is provided with a primary winding, a secondary winding, and a package containing both the primary winding and the secondary winding. The number of turns of the wire and the secondary winding is 20 turns and 500 turns. The wire diameter of the primary winding and the secondary winding is φ0.2,
φ0.05.

[0004]

The above-mentioned trigger coil has two terminals to which one end and the other end of the primary winding are connected, and two terminals to which one end and the other end of the secondary winding are connected. A four-terminal type having a total of four terminals; one common terminal to which both one end of the primary winding and one end of the secondary winding are commonly connected; There are two types, a three-terminal type having a total of three terminals of two terminals to which the other end of the secondary winding is connected. here,
Particularly, in the case of a three-terminal type trigger coil, a primary winding having a large wire diameter and a secondary winding having a small wire diameter are wound around the same portion of a common terminal and are solder-mounted on a circuit board. There is a problem that the secondary winding having a small diameter is broken by a small external force.

An object of the present invention is to provide a trigger coil in which disconnection of a secondary winding is prevented based on the above circumstances.

[0006]

According to the present invention, there is provided a trigger coil comprising: a primary winding; a secondary winding;
A package containing both the primary winding and the secondary winding; a common terminal to which both one end of the primary winding and one end of the secondary winding are connected; A primary terminal to which the other end of the winding is connected, and a secondary terminal to which the other end of the secondary winding is connected, and a current flows between the primary terminal and the common terminal. Thereby, in the trigger coil for generating a trigger voltage applied to the trigger electrode of the flash arc tube at the secondary terminal, the common terminal extends through the package and has one end connected to the circuit board. One end of the primary side winding is connected to an outlet portion from the package on the side of the common terminal connected to the circuit board, and the common terminal is connected to the circuit board from the circuit board. On the far side, from the package above The outlet portion, one end of the secondary winding is characterized by comprising connected.

The trigger coil of the present invention has a common terminal
One end of the primary winding is connected to the part connected to the circuit board, and one end of the secondary winding is connected to the part of the common terminal that is remote from the circuit board. Therefore, even when the trigger coil is mounted on a circuit board and an external force is applied, the conventional primary winding having a large wire diameter and the secondary winding having a small wire diameter have a common terminal. Compared to a trigger coil wound around the same point, the external force has less effect on one end of the secondary winding, and thus disconnection of the secondary winding is prevented.

[0008]

Embodiments of the present invention will be described below.

FIG. 1 is a diagram showing a state in which a trigger coil according to an embodiment of the present invention is viewed from three directions, and a perspective view of the trigger coil. FIG. 2 is an equivalent circuit of the trigger coil shown in FIG.

FIG. 1A shows terminals 14 and 15 which will be described later and constitute a trigger coil 10 according to an embodiment of the present invention.
Is shown as viewed from above. FIG. 1B shows a state where the trigger coil 10 shown in FIG. Further, FIG. 1C shows a state where the trigger coil 10 shown in FIG. 1A is viewed from the direction of arrow B. Also, in FIG. 1 (d),
A perspective view of the trigger coil 10 is shown.

The trigger coil 10 includes a primary winding 11 and a secondary winding 12 shown in FIG.
A molded part 13 (corresponding to a package according to the present invention) shown in FIG. 1 which incorporates both the primary winding 1 and the secondary winding 12 is provided. The number of turns of the primary winding 11 is smaller than the number of turns of the secondary winding 12, and the wire diameter of the primary winding 11 is φ0.3.
5, and the wire diameter of the secondary winding 12 is φ0.05.

The trigger coil 10 has a structure shown in FIG.
(D) and as shown in FIG. 2, an outlet portion 14 a to which one end 11 a (end of winding end) of the primary winding 11 is connected.
Terminal 1b of the secondary winding 12 and a common terminal 1 in the form of a metal rod having an outlet portion 14b connected to one end 12a (end of winding end).
4 are provided. The trigger coil 10 further includes a metal rod-shaped primary terminal 15 to which the other end 11 b (winding start end) of the primary winding 11 is connected, and a secondary winding 12.
And a secondary terminal 16 in the form of a metal bar to which the other end 12b (the leading end of the winding) is connected. Further, the trigger coil 10 is provided with the trigger coil 10 shown in FIG.
An empty pin (NC) 17 for stable mounting on a circuit board (not shown) provided below the trigger coil 10 shown in (d) is also provided. This trigger coil 1
0 causes a current to flow between the primary terminal 15 and the common terminal 14 to cause the secondary terminal 16 to generate a trigger voltage to be applied to a trigger electrode of a flash tube described later.

The common terminal 1 constituting the trigger coil 10
As shown in FIGS. 1C and 1D, reference numeral 4 denotes a pin extending through the molded component 13 and having one end connected to the circuit board. One end 11a of the primary winding 11 is connected to the outlet portion 14a from the molded component 13 of the common terminal 14 on the side connected to the circuit board, and the common terminal 14 is connected to the side remote from the circuit board. One end 12a of the secondary winding 12 is connected to an outlet portion 14b from the molded part 13. Further, the molded component 13 constituting the trigger coil 10 has a hole 13b into which a rod-shaped core (not shown) is inserted.

The thus configured trigger coil 10
One end 11a of the primary winding 11 is connected to an outlet portion 14a of the common terminal 14 on the side connected to the circuit board, and is connected to an outlet portion 14b of the common terminal 14 on the side remote from the circuit board. Since one end 12a of the secondary winding 12 is connected, even when the trigger coil 10 is mounted on a circuit board and an external force is applied,
Compared with a conventional trigger coil in which a primary winding having a large wire diameter and a secondary winding having a small wire diameter are wound around the same portion of a common terminal, one end 12a of the secondary winding 12 due to the external force is compared.
, The disconnection of the secondary winding 12 is prevented.

Next, a case where the trigger coil 10 is incorporated in a flash generation circuit mounted on a camera will be described.

FIG. 3 is a diagram showing a flash generating circuit incorporating the trigger coil shown in FIG.

The flash generating circuit 100 shown in FIG. 3 includes the trigger coil 10 shown in FIG.
, A main capacitor 31, resistance elements 32 and 33,
A trigger capacitor 34, a thyristor 35, and terminals 36, 38, and 39 are provided.

The flash generating circuit 100 is mounted on a camera as described above, and a voltage Va boosted by a boosting circuit connected to a built-in battery for controlling the entire camera is applied to a terminal 36. You. This terminal 36
And a terminal 39 held at the ground GND potential, a resistance element 32 and a trigger capacitor 34 connected in series, the flash tube 20, and the main capacitor 3.
1 are arranged in parallel. The flash tube 20 has an anode 21, a cathode 22, and a trigger electrode 23, and contains xenon (XE) gas inside.

The primary terminal 15 formed by winding the primary winding 11 constituting the trigger coil 10 is connected to a resistance element 32.
And the connection point of the trigger capacitor 34. Also, the secondary winding 1 constituting the trigger coil 10
2 is wound around the secondary terminal 16,
Is connected to the trigger electrode 23 of Further, the common terminal 14 constituting the trigger coil 10 is connected to the thyristor 3
5 is connected to the terminal 39. The gate of the thyristor 35 is connected to a terminal 38 to which a control signal Ft is input and to a terminal 39 via a resistance element 33.

The flash generation circuit 100 thus configured
At the beginning, the control signal Ft at the “L” level is input to the terminal 38. In addition, sufficient power is accumulated in the main capacitor 31 by the voltage Va applied to the terminal 36. Further, the terminal 36 → the resistance element 32 →
Through the path from the trigger capacitor 34 to the terminal 39,
Power is also stored in the trigger capacitor 34.

Next, at the time of photographing, an "H" level control signal Ft is input to the terminal 38 in synchronization with the movement of the shutter of the camera.
Is entered. Then, the thyristor 35 is turned on, and the electric power stored in the trigger capacitor 34 is discharged via the primary winding 11 → the thyristor 35 → the terminal 39. As a result, a current flows through the primary winding 11 and an electromotive force is induced in the secondary winding 12. here,
Since the number of turns of the secondary winding 12 is larger than the number of turns of the primary winding 11, the electromotive force induced in the secondary winding 12 is amplified and increased. Since such a large electromotive force is applied to the trigger electrode 23 of the flash arc tube 20 as a trigger voltage, the xenon gas sealed in the flash arc tube 20 is excited, and the (+) side of the main capacitor 31 → the anode 21 → The cathode 22 → The electric power stored in the main capacitor 31 is discharged through the discharge loop on the (−) side of the main capacitor 31, and the flash tube 20 generates a flash. In this way, when the subject brightness is insufficient,
Flash photography is performed by a flash light generation circuit 100 mounted on the camera to take a picture.

[0022]

As described above, according to the present invention,
The disconnection of the secondary winding constituting the trigger coil is prevented.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state in which a trigger coil according to an embodiment of the present invention is viewed from three directions, and a perspective view of the trigger coil.

FIG. 2 is an equivalent circuit of the trigger coil shown in FIG.

FIG. 3 is a diagram showing a flash generating circuit in which the trigger coil shown in FIG. 1 is incorporated.

[Explanation of symbols]

 Reference Signs List 10 Trigger coil 11 Primary winding 11a One end of primary winding 11b The other end of primary winding 12 Secondary winding 12a One end of secondary winding 12b The other end of secondary winding 13 Molded part 13b Hole 14 Common terminal 14a, 14b Exit part of common terminal 15 Primary terminal 16 Secondary terminal 17 Empty pin (NC) 20 Flash tube 21 Anode 22 Cathode 23 Trigger electrode 31 Main capacitor 32, 33 Resistance element 34 Trigger capacitor 35 Thyristor 36, 38, 39 Terminal 100 Flash generation circuit

Claims (1)

[Claims] A primary winding, a secondary winding, a package containing both the primary winding and the secondary winding, an end of the primary winding and the secondary winding. A common terminal to which both ends of the winding are connected, a primary terminal to which the other end of the primary winding is connected, and a secondary terminal to which the other end of the secondary winding is connected. A trigger coil that generates a trigger voltage to be applied to a trigger electrode of a flash tube by causing a current to flow between the primary terminal and the common terminal, wherein the common terminal is Having a pin shape extending through the package and having one end connected to a circuit board, wherein the primary terminal is provided at an outlet from the package on a side of the common terminal connected to the circuit board. One end of the winding is connected and the common terminal Trigger coil, wherein the away from the plate side, the outlet portion from the package and that the one end of the secondary winding is connected.