JPH11186065A - Oscillation transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oscillation transformer capable of improving the safety of an automatic stopping type strobe circuit. SOLUTION: Since an L-shaped intermediate output terminal 15 is embedded and fixed in a bobbin 14 of an oscillation transformer 10, an intermediate output terminal 15 does not fall out of the bobbin 14, even if it receives impact. The middle part of a secondary coil 12 is pulled out as a loop and is cut into two, with one end part 12a thereof being soldered to an arm part 15a of the intermediate output terminal 15, and other end part 12b being soldered to an arm part 15b after each thereof is wound in several turns. End parts 12a, 12b of the secondary coil 12 are connected to the intermediate output terminal 15 from different directions, and they are in positions apart from each other. Therefore, if either or both of the end parts 12a, 12b are off from the intermediate output terminal 15 or cut, the secondary coil 12 is cut without mutual contact thereof. Consequently, charge operation itself is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillation transformer for charging a main capacitor of a flash circuit.

[0002]

2. Description of the Related Art As a strobe circuit of a strobe device, there has been known an automatic stop type strobe circuit which stops charging when a main capacitor is charged to a specified charging voltage (for example, Japanese Utility Model Application Laid-Open No. 60-43399). No.). In this strobe circuit, an intermediate output terminal is provided in a secondary coil of an oscillation transformer, and is connected to a stopping transistor via a diode and a zener diode.

[0003] The potential of the intermediate output terminal changes proportionally with an increase in the charging voltage of the main capacitor. When the main capacitor is charged to a specified charging voltage, a zener current flows through the zener diode. As a result, the stop transistor is turned on by the base current flowing, the input terminals (emitter and base terminals) of the oscillation transistor are connected, the oscillation of the oscillation transistor is stopped, and the charging of the main capacitor is stopped.

The oscillation transformer is formed by winding a primary coil and a secondary coil around a bobbin made of plastic, and a plurality of pin-shaped terminals are press-fitted on a side of the bobbin to be mounted on a printed circuit board. Among these terminals, a wire in the middle of the secondary coil is drawn out in a loop shape from the intermediate output terminal, and the tip is soldered.

[0005]

By the way, the above-mentioned strobe device is used by being incorporated in or externally attached to a lens-equipped film unit or camera in which a photographic film is incorporated in a unit body having a simple photographing mechanism. Therefore, a strong impact may be caused by dropping when carrying the mobile phone. In such a case, the intermediate output terminal of the oscillation transformer may fall out of the bobbin or may fall out halfway, and the connection between the intermediate output terminal and the secondary coil may be released. When the connection between the intermediate output terminal and the secondary coil is released, charging of the main capacitor is no longer stopped, and recharging is impossible due to exhaustion of the power battery, leakage of the power battery, and film with a lens due to heat generation of the main capacitor. Deformation of the unit or camera, burns of the user, rupture of the main condenser, etc. occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an oscillation transformer with improved safety of an automatic stop type strobe circuit.

[0007]

In order to achieve the above object, an oscillation transformer according to the present invention is an oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil is inductively coupled to the primary coil. In an oscillation transformer having a secondary coil and an intermediate output terminal used for automatically stopping a charging operation in the middle of the secondary coil, an intermediate portion of the secondary coil to be connected to the intermediate output terminal is provided. The secondary coil is cut into two parts, and each end of the cut secondary coil is connected to the intermediate output terminal from different directions.

An oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil and a secondary coil inductively coupled to the primary coil are wound around a bobbin, respectively, and a charging operation is performed between the secondary coils. In an oscillation transformer connected to an intermediate output terminal used for automatically stopping the
A conductive member in the shape of a letter, this corner is fixed so as to be embedded in the bobbin, and the middle of the secondary coil to be connected to the intermediate output terminal is cut into two,
Each end of the cut secondary coil is connected to a portion of the intermediate output terminal projecting from the bobbin at a right angle to each other.

An oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil and a secondary coil inductively coupled to the primary coil are wound around a bobbin, respectively, and a charging operation is performed between the secondary coils. In the oscillation transformer to which the intermediate output terminal used for automatically stopping the motor is connected, the middle of the secondary coil to be connected to the intermediate output terminal is cut into two, and each end of the cut secondary coil is cut off. Are connected to the intermediate output terminals from different directions, respectively, and partition plates are provided between the respective ends of the secondary coil extending from the intermediate output terminals.

An oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil and a secondary coil inductively coupled to the primary coil are wound around a bobbin, respectively, and a charging operation is performed between the secondary coils. In an oscillation transformer connected to an intermediate output terminal used for automatically stopping the motor, a projection is provided near the intermediate output terminal of the bobbin, and two intermediate portions of a secondary coil to be connected to the intermediate output terminal are provided. And one end of the cut secondary coil is entangled with the protrusion, and then connected to the intermediate output terminal, and the other end is connected to the intermediate output terminal from a direction different from the one end. Connected to.

Each cut end of the secondary coil is connected to the intermediate output terminal by being entangled with the intermediate output terminal and then soldered.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, a flash circuit using an oscillation transformer according to the present invention roughly comprises a boosting section 20 and a charging / emitting section 40. The booster 20 includes, in addition to the oscillation transformer 10 according to the embodiment of the present invention, a battery 21 having an electromotive force of 1.5 V, an NPN-type oscillation transistor 22, a rectifying diode 25, a strobe charging switch 26, and a power supply source. It comprises an oscillation stop circuit 35 and the like. Note that after the strobe charging switch 26 is turned on, the strobe charging switch 26 is always turned on until the next off-switching operation is performed.

The oscillation transformer 10 includes a primary coil 11, a secondary coil 12, and a tertiary coil 1 which are inductively coupled to each other.
The coils 11 to 13 are wound around a plastic bobbin 14 (see FIG. 1). In this oscillation transformer 10, each terminal of the primary coil 11 serves as a first terminal 10 a and a second terminal 10 b, one terminal of the secondary coil 12 serves as a fifth terminal 10 e, and the other terminal serves as one terminal of the tertiary coil 13. And the fourth terminal 10d, which is a shared terminal,
The other terminal of the tertiary coil 13 is a third terminal 10c (see FIG. 1). The secondary coil 12 is provided with an intermediate output terminal 15.

The first terminal 10a to the fifth terminal 10d are rectangular or columnar conductive members, and are press-fitted into the eaves 14a of the bobbin 14, respectively. Intermediate output terminal 15
1 has a different shape from the first terminal 10a to the fifth terminal 10d, and has an L-shape as shown in FIGS. The eave portion 14a is provided with a hole 16 formed in the thickness direction and a groove 17 formed on the lower surface of the eave portion 14a in a direction perpendicular to the thickness direction.
The arm 15b is fitted into the groove 17 so as to protrude above the eaves 14a through the groove 17 and the other arm 15b is fitted into the groove 17. Thus, after each of the coils 11 to 13 is wound around the bobbin, the intermediate output terminal 15
It does not fall out or fall out halfway. In addition, the intermediate output terminal 15 is formed by bobbin 14 by insert molding.
May be fixed at the time of molding.

The intermediate portion of the secondary coil 12 to be connected to the intermediate output terminal 15 is drawn out in a loop and cut into two parts. The cut end 12a on the fifth terminal 10e side is connected to the intermediate output terminal 15 The end 12b on the side of the fourth terminal 10d and the end 12b on the side of the fourth terminal 10d are wound around the other arm 15b a plurality of times (two times in the drawing) and then soldered. Thus, the end portions 12a of the secondary coil 12,
12b are connected to the intermediate output terminal 15 from different directions and are at positions separated from each other.
Even if one or both of 2b come off or cut off from the intermediate output terminal 15, they do not contact each other.

Thus, when one or both of the ends 12a and 12b are cut, the intermediate output terminal 15
Is not only disconnected from the secondary coil 12, but also the secondary coil 12 itself is disconnected and the connection between the fourth terminal 10d and the fifth terminal 10e is also released. Is stopped. Accordingly, recharging failure due to consumption of the battery 21, leakage of the battery 21, deformation of the lens-equipped film unit or camera due to heat generation of the main capacitor, burn of the user, rupture of the main capacitor, and the like due to the stoppage of the charging operation. It can be prevented beforehand.

The oscillation transformer 10 has a first terminal 10a connected to the collector terminal of the oscillation transistor 22 and a second terminal 10b connected to the plus terminal of the battery 21. The third terminal 10c is connected to a resistor 34a, a strobe charging switch 2
The fourth terminal 10d is connected to the positive terminal of the battery 21 via the second terminal 6 and the base terminal of the oscillation transistor 22. In addition, the fifth terminal 10 e is connected to the negative side of the charging light emitting unit 40 (the negative terminal side of the main capacitor 41) via the rectifying diode 25. The connection direction of the rectifying diode 25 is such that the cathode is on the fifth terminal 10e side. The emitter terminal of the oscillation transistor 22 is connected to the negative terminal of the battery 21 and is connected to ground (G
ND).

The oscillation transistor 22 and the oscillation transformer 10 connected in this manner constitute a known blocking oscillation circuit for converting the low voltage of the battery 21 to a high voltage and charging the main capacitor 41 with a high voltage. doing.
The oscillating transistor 22 starts operating when the strobe charging switch 26 is turned on, and causes a primary current (collector current) to flow through the primary coil 11. Then, the oscillation transistor 22 oscillates by increasing the collector current by increasing the base current by the positive feedback action from the oscillation transformer 10.

The secondary coil 12 includes an oscillation transistor 2
During the oscillation of 2, a high voltage, for example, an electromotive force (AC voltage) of about 1000 V is generated according to the winding ratio between the primary coil 11 and the secondary coil 12. The rectifying diode 25 supplies only the secondary current flowing in the direction from the fifth terminal 10e to the fourth terminal 10d to the charging light emitting unit 40 by the electromotive force.

The potential Va of the intermediate output terminal 15 oscillates due to the oscillating operation of the blocking oscillation circuit, and its overall level changes proportionally with an increase in the charging voltage of the main capacitor 41. In this strobe circuit, since negative charging is performed, the potential Va of the intermediate output terminal is used.
Decreases proportionally with an increase in the charging voltage.

The intermediate output terminal 15 is connected to the main capacitor 4
1 reaches the specified charging voltage, and when an electromotive force is generated in the secondary coil 12, the potential Va and the potential V of the fourth terminal 10d are
b is equal to a predetermined voltage Vo (voltage: Vb−Va).
The position in the secondary coil 12 is determined so as to be n. The voltage Von is a voltage value obtained by adding a voltage drop (about 0.6 V) of the rectifying diode 36 and the like to a Zener voltage Vz of a Zener diode 37 described later. In order to use a Zener diode having a low Zener voltage Vz, Voltage Vo
n is set to a low voltage.

In this example, since the Zener voltage Vz of the Zener diode 37 is 10 V, the number of windings between the intermediate output terminal 15 and the fourth terminal 10 d is about one with respect to the number of windings of the secondary coil 12. An intermediate output terminal 15 is provided at a position where the voltage is / 30, and the voltage Von is 10.6 V. For example, when a zener diode 37 having a zener voltage Vz of 30 V is used, the number of turns of the secondary coil 12 is The number of windings between the intermediate output terminal 15 and the fourth terminal 10d is about 1/1
The intermediate output terminal 15 is provided at a position where the voltage Vo becomes zero.
n is set to 30.6V.

The oscillation stop circuit 35 includes a rectifying diode 3 connected in series to the intermediate output terminal 15 of the secondary coil 32.
6, the resistors 36a and 37a, and the zener diode 37
And a stopping capacitor 39 in addition to the stopping transistor 38 and the like. The rectifying diode 36
And the Zener diode 37 constitute a temperature compensation circuit.

The rectifier diode 36 is connected to the intermediate output terminal 15
Is provided to rectify the voltage (alternating current) generated at the rectifier and extract only the negative voltage. The stop transistor 38 is
The base terminal is connected to a zener diode 37 via a resistor 37a.
The emitter terminal and the collector terminal are connected to the base terminal and the emitter terminal of the oscillation transistor 22, respectively.

The Zener diode 37 has a Zener voltage Vz
Is a low voltage, for example, 10V.
A DC voltage obtained by rectifying the voltage between the terminal 10d and the intermediate output terminal 15 with the rectifier diode 36 is applied. And
When the main capacitor 41 reaches the specified charging voltage,
The DC voltage rectified by the rectifying diode 36 is set to be the Zener voltage Vz of the Zener diode 37,
When the main capacitor 41 reaches the specified charging voltage, the Zener diode 37 allows a Zener current (a reverse current) to flow.

When the Zener diode 37 is not passing a Zener current, the stop transistor 38 is turned off because no base current flows.
In the case where the zener current flows through 7, that is, when the cathode potential of the zener diode 37 becomes 0 V or less, a voltage higher than the operating voltage is applied between the emitter and the base, and the zener current flows as the base current. Therefore, the transistor is turned on (a state of conduction between the emitter and the collector).

When the stop transistor 38 is turned on, the base terminal and the emitter terminal, which are the input terminals of the oscillation transistor 22, are connected to have the same potential, and the oscillation transistor 22 is turned off.

As described above, since the stop transistor 38 is activated when the potential Va of the intermediate output terminal 15 of the secondary coil 12 drops to a predetermined level, the inexpensive rectifying diode 36 and the zener voltage Vz are reduced. Using a low-priced zener diode 37, the main capacitor 4
Stop transistor 38 when 1 reaches a specified charging voltage
Can be turned on to stop charging. Thereby, the manufacturing cost of the strobe circuit can be reduced.

In this strobe circuit, when the main capacitor 41 is charged, the strobe charging switch 26 is always on, so that the stop transistor 3 is momentarily turned on.
Even when 8 is turned on, the operation of the oscillation transistor 22 may not be stopped. For this purpose, Zener diode 3
A stop capacitor 39 is connected between the cathode 7 and the fourth terminal 10d of the oscillation transformer 10 without using a resistor or the like.

When the main capacitor 41 reaches the specified charging voltage, the stopping capacitor 39 is connected to the Zener diode 3.
7 is charged to an appropriate charging voltage by the Zener current flowing through the capacitor. After this charging, the stopping capacitor 39 is connected to the resistor 37
The discharge is performed via a, and a base current is supplied to the stop transistor 38 to turn on the stop transistor 38.

The stopping capacitor 39 is connected to the resistor 37.
The base current is caused to flow through the stop transistor 38 for a relatively long time by discharging the electric current through the a. As a result, the ON time of the stop transistor 38 is lengthened, and the oscillation of the oscillation transistor 22 is reliably stopped. The ON time of the stop transistor 38 is
It can be set by adjusting the time constant determined by the capacitance of the stopping capacitor 39 and the resistance of the resistor 37a. In this example, the stopping capacitor 39 having a capacitance of 47 μF and the resistance of 10 KΩ are set. The actual measurement time is 0.3 sec using the resistor 37a.

After the main capacitor 41 is charged to the specified charging voltage, if the strobe charging switch 26 is on, the discharging voltage of the stopping capacitor 39 causes a drop in the charging voltage, and the stopping transistor 38 is turned off. Therefore, the oscillation transistor 22 starts operating again.
Immediately thereafter, the stop capacitor 39 is charged again, and the operation of stopping the oscillation transistor 22 by discharging the stop capacitor 39 is repeated. Thereby, charging is performed intermittently so as to compensate for the natural discharge of the main capacitor 41.

Further, the light emitting diode 52 intermittently emits light and turns off in response to the intermittent charging, and blinks. This blinking interval is determined by the stopping transistor 3
At the same time as the setting of the on-time of 8, the time can be set by adjusting the time constant determined by the capacitance of the stopping capacitor 39 and the resistance value of the resistor 37a. For example, when a light emitting diode 52 similar to the above is added to a strobe circuit in which a zener current is directly passed to operate the stop transistor 38, variations in the ambient temperature, the leakage current of the main capacitor 41, the zener diode The blinking interval of the light emitting diode may change ten times or more due to the individual difference of the light emitting diode. However, in this strobe circuit, the blinking interval can be fixed.

The charging light emitting section 40 includes a main capacitor 4
1, strobe discharge tube 42, trigger electrode 42a, trigger capacitor 44, trigger transformer 45, trigger switch 4
6, a light emission selection switch 54 and the like. The main capacitor 41 has both terminals connected to the strobe discharge tube 4.
2 is connected to both electrodes, and the plus terminal is
1, is connected to the ground (GND), and the negative terminal is connected to the anode of the charging diode 25. In the flash circuit of the present embodiment, the specified charging voltage of the main capacitor 41 is set to 300 V,
When the main capacitor 41 is charged to the specified charging voltage, the strobe discharge tube 42 can emit light with a designed light amount.

The current (secondary side current) supplied from the booster 20 charges the main capacitor 41 and the trigger capacitor 44. Main capacitor 41
In this case, the charging voltage is increased by this charging. The main capacitor 41 is negatively charged so as to lower the negative potential while maintaining the positive potential equal to the negative potential of the battery 21. Therefore, the main capacitor 41 is based on the negative potential. The magnitude of the positive potential is the charging voltage.

The trigger switch 46 is turned on and off in conjunction with the operation of the shutter, and is turned on when the shutter is fully opened. When the trigger switch 46 is turned on, the trigger capacitor 44 is discharged, and the discharged current flows through the primary coil 45 a of the trigger transformer 45. As a result, a high voltage, for example, a trigger voltage of 4 KV is generated in the secondary coil 45b. This trigger voltage is applied to the strobe discharge tube 42 via a trigger electrode 42a arranged close to the strobe discharge tube 42. By the application of the trigger voltage, the Xe gas in the strobe discharge tube 42 is ionized, the resistance between both electrodes of the strobe discharge tube 42 is broken, the main capacitor 41 is discharged, and the strobe discharge tube 42 emits light.

One end of the trigger capacitor 44 and a common terminal of the primary coil 45a and the secondary coil 45b of the trigger transformer 45 are connected to the plus terminal of the battery 21, and the light emitting selection switch 5 is connected in series with the trigger capacitor 44.
4 are connected. The flash selection switch 54 is turned on and off in conjunction with the flash charging switch 26.

When the light emission selection switch 54 is turned on, the trigger capacitor 44 is charged by the booster 20 in operation, and the charged trigger capacitor 44 is discharged when the trigger switch 46 is turned on. Then, a trigger voltage is applied to the strobe discharge tube 42. By turning off the flash charging switch 26 and turning off the light emission selection switch 54, the trigger capacitor 44 will not be discharged even if shooting is performed with the main capacitor 41 charged. Is forbidden.

The operation of the above configuration will be briefly described.
When a film unit with a lens or a camera on which the above-described strobe circuit is mounted is dropped, the oscillation transformer 10 receives a strong shock. However, since the intermediate output terminal 15 is L-shaped, the intermediate output terminal 15 It does not drop off from the bobbin 14 and does not fall out halfway. Further, the end portions 12a, 1
If one or both of 2b are disconnected from or disconnected from the arms 15a, 15b of the intermediate output terminal 15, power is not supplied to the main capacitor 41 itself, and an accident occurs because charging is not stopped. There is no fear.

The ends 12a, 12a of the secondary coil 12
When both of the two ends b are disengaged from the arms 15a and 15b of the intermediate output terminal 15, and the free ends 12a and 12b contact each other without contacting the intermediate output terminal 15, the charging operation does not automatically stop. However, since the ends 12a and 12b are connected to the intermediate output terminal 15 in a state where they are largely separated from each other, it is considered that the probability of such an accident occurring is extremely low.

The operation of the above strobe circuit will be described assuming that the oscillation transformer 10 is in a perfect state. For example, when the flash charging switch 26 is turned on while the main capacitor 41 is not charged to the specified charging voltage, a base current flows from the battery 21 to the oscillation transistor 22 via the flash charging switch 26. As a result, the oscillation transistor 22 starts operating, and the oscillation transformer 10
Oscillates due to the feedback action of Then, since the flash charging switch 26 is continuously turned on, the oscillation transistor 22 continuously oscillates.

While the oscillation transistor 22 is oscillating, the main capacitor 41 is charged with the secondary current flowing by the electromotive force generated in the secondary coil 12 of the oscillation transformer 10, and the light emission selection switch 54 is turned on. Therefore, the trigger capacitor 44 is charged by the secondary current flowing through the secondary coil 12.

When the charging of the main capacitor 41 proceeds and the charging voltage increases, the third terminal 10 of the tertiary coil 13
During a period in which the potential of c gradually decreases and no back electromotive force is generated, the potential of the third terminal 10c becomes lower than the potential of the fourth terminal, and a forward voltage is applied to the light emitting diode 52. . However, when the charging voltage of the main capacitor 41 is relatively low, the light emitting diode 52 does not emit light because the potential difference is small.

When the charging voltage of the main capacitor 41 becomes 250 V or more, the potential difference between the third terminal 10c and the fourth terminal 10d increases outside the period in which the back electromotive force is generated in the oscillation transformer 10. , Light emitting diode 52
Can be visually recognized. Then, when the charging voltage of the main capacitor 41 is charged to the specified charging voltage of 300 V, the potential difference between the third terminal 10c and the fourth terminal 10d becomes larger, and the light emitting diode 52 emits light brightly.

On the other hand, as the charging voltage of the main capacitor 41 increases, the potential Va of the intermediate output terminal 15 increases.
Gradually falls according to the charging voltage. When the main capacitor 41 reaches the specified charging voltage of 300 V,
A zener current flows through the zener diode 37. The Zener current is supplied to the fourth terminal 10 through the stopping capacitor 39.
Since the current flows from d to the intermediate output terminal 15, the stopping capacitor 39 is charged with the zener current. Then, since the stop capacitor 39 is directly charged with the zener current without using a resistor, the charging is completed in a short time (about 10 msec in this example).

Immediately after the charging voltage of the main capacitor 41 reaches the specified charging voltage, the Zener current flows through the stopping capacitor 39, so that the base-emitter voltage becomes 0 V and the stopping transistor 38 does not turn on.
After the charging of the stopping capacitor 39, the charging voltage of the stopping capacitor 39 is given as the base-emitter voltage of the stopping transistor 38, and the charge of the stopping capacitor 39 is transferred to the stopping capacitor 39. The transistor 38 is discharged in a closed circuit of the emitter terminal, the base terminal, and the resistor 37a, the base current flows, and the stop transistor 38 is turned on. Thereby, the battery 2
Since the base current supplied to the oscillation transistor 22 from 1 through the strobe charging switch 26 is not supplied, the oscillation transistor 22 is stopped, and the charging of the main capacitor 41 is stopped.

The discharging of the stopping capacitor 39 is performed by the resistor 37.
a, the stop transistor 38 is
The base current flows for an ON time (about 0.3 sec in this example) according to a time constant determined by the capacitance of the stopping capacitor 39 and the resistance value of the resistor 37a, and the capacitor is turned on. As a result, the supply of the base current to the oscillation transistor 22 is stopped for the ON time, and the strobe charging switch 26 is turned on. However, during this time, the operation of the oscillation transistor 22 is stopped and the main capacitor is turned off. The charging of 41 is stopped.

When the discharging of the stopping capacitor 39 proceeds and the charged voltage drops to a predetermined voltage, the stopping transistor 38 is turned off. Since the strobe charging switch 26 is on, when the stop transistor 38 is turned off, supply of the base current from the battery 21 to the oscillation transistor 22 is restarted, and the oscillation transistor 22 starts oscillating again. However, since the main capacitor 41 has already been charged to the specified charging voltage, a zener current flows through the zener diode 37 immediately after the restart of the oscillation, and the stop capacitor 39 is charged in the same manner as described above. Later, the stop transistor 38 is turned on by the discharge of the stop capacitor 39, the oscillation transistor 22 is stopped, and the charging of the main capacitor 41 is stopped.

Thereafter, when the stop transistor 38 is turned off again, the oscillation transistor 22 is oscillated and stopped, that is, the main capacitor 41 is charged and the charging is stopped, and the strobe charge switch 26 is turned on. It is repeated while you are. Thereby, the charging is performed intermittently so as to compensate for the spontaneous discharge of the main capacitor 41, and the main capacitor 41 is maintained at a substantially constant charging voltage.

At this time, the light emitting diode 52 blinks. That is, the light emitting diode 52 repeats the operation of turning on the light while the oscillation transistor 22 is oscillating and the main capacitor 41 is being charged, and turning off the light when the charge is stopped by the stop transistor 22, so that the light emitting diode 52 has a constant interval. Will blink.

When the shutter button of the lens-equipped film unit or camera equipped with the flash circuit is pressed, the trigger switch 46 is turned on at the moment when the shutter blades are fully opened, and the light emission selection switch 54 is turned on in advance. The trigger capacitor 44 discharges. As a result, the trigger voltage generated in the trigger transformer 45 is applied to the strobe discharge tube 42, and the main capacitor 41
Is discharged and strobe light emission is performed.

When photographing without flash emission, the flash charge switch is turned off and the shutter button is pressed. As a result, the light emission selection switch 54 is turned off, and regardless of whether the main capacitor 41 is charged or not, the strobe light is not emitted because the trigger capacitor 44 does not discharge. Also, since the flash charging switch 26 is turned off, the main capacitor 4
1 is no longer charged.

Next, in the oscillation transformer 60 shown in FIG. 4, the intermediate output terminal 61 has the same prismatic shape as the other terminals, and the ends 12a and 12b of the secondary coil 12 are respectively set from different directions. End portions 12a, 1 extending from the intermediate output terminal 61,
Partition plate 62a formed integrally with bobbin 62 between 2b
Is provided. Even if the intermediate output terminal 61 is in a semi-missing state by this partition plate 62a, and both ends 12a and 12b of the secondary coil 12 are disengaged from the intermediate output terminal 61, the free ends 12a, 12b do not contact each other.

Next, the oscillation transformer 70 shown in FIG. 5 includes an end portion 12a of the secondary coil 12
Grooves 73 for guiding the respective 12b to the intermediate output terminal 61,
74, the eaves 71a between the grooves 73, 74 are slightly protruded, and a convex portion 75 is formed integrally with the bobbin 71 near the upper groove 74. Then, one end 12a of the secondary coil 12 is entangled with the intermediate output terminal 61 via the groove 73 and soldered, and the other end 12b is entangled with the projection 75 via the groove 74, and then the intermediate output terminal It is entangled with 61 and soldered. As a result, for some reason, the end portions 12a, 1
Either one or both of 2b are intermediate output terminals 6
Even if it is deviated from 1, at least the end 12b entangled with the convex portion 75 does not move freely, so that the ends 12a and 12b do not contact each other. Therefore, it is possible to prevent heat generation of the main capacitor, liquid leakage of the battery, and the like due to the charging not being stopped.

In the above-described embodiment, the protruding portion that is entangled with the bobbin before the end of the secondary coil is connected to the intermediate output terminal is formed integrally with the bobbin.
For example, a metal pin or the like may be pressed into the bobbin. Alternatively, two protrusions may be provided, and both ends of the secondary coil may be entangled before connecting both ends to the intermediate output terminal. Further, each of the terminals including the intermediate output terminal, the bobbin, the partition plate, and the projection used in the above embodiment may have different shapes. In the above-described embodiment, the flash circuit is configured to continuously charge the main capacitor. However, the flash circuit may be configured such that the charging switch is turned on once and then turned off to continue charging.

[0056]

As described above, according to the oscillation transformer of the present invention, the middle of the secondary coil to be connected to the intermediate output terminal is cut into two, and each of the cut secondary coils is cut. Since the ends are connected to the intermediate output terminal from different directions from each other, when each end of the secondary coil comes off from the intermediate output terminal, the ends do not contact each other and the main capacitor is charged. Nothing is done. Therefore, recharging is impossible due to power supply battery depletion, leakage of the power supply battery, deformation of the lens-equipped film unit or camera due to heat generation of the main capacitor, burns of the user, and the like, due to the fact that charging of the main capacitor is not stopped.
Rupture of the main capacitor can be prevented beforehand, and the safety of the automatic stop type strobe circuit can be improved.

Further, the intermediate output terminal is formed of an L-shaped conductive member, and this corner is fixed so as to be embedded in the bobbin. Since the ends of the coil are cut into two ends, the intermediate output terminal does not fall out of the bobbin even when subjected to a strong shock, and one or both of the ends are connected to the intermediate output terminal. Even if they are separated from each other, the ends are largely separated from each other, so that the free ends can be prevented from contacting each other.

Further, since the partition plate is provided between the ends of the secondary coil extending from the intermediate output terminal, one or both of the cut ends of the secondary coil may come off from the intermediate output terminal. Even so, the free end portions can be prevented from contacting each other.

Also, a convex portion is provided near the intermediate output terminal of the bobbin, one cut end of the secondary coil is entangled with the convex portion, and then connected to the intermediate output terminal, and the other end is connected to the one end. Since the terminal is connected to the intermediate output terminal from a direction different from that of the end, the degree of freedom of the one end is limited, and the ends can be prevented from contacting each other.

Further, since each cut end of the secondary coil is entangled with the intermediate output terminal and then soldered, the detachment of each end from the intermediate output terminal can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of an oscillation transformer embodying the present invention.

FIG. 2 is a circuit diagram showing a strobe circuit using the oscillation transformer shown in FIG.

FIG. 3 is a sectional view showing a structure of an intermediate output terminal of the oscillation transformer shown in FIG.

FIG. 4 is a perspective view showing an embodiment of an oscillation transformer provided with a partition plate.

FIG. 5 is a perspective view showing an embodiment of an oscillation transformer provided with a convex portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Oscillation transformer 10a-10e Terminal 11-13 Coil 12a, 12b End 14, 62, 71 Bobbin 14a, 71a Eaves 15, 61 Intermediate output terminal 35 Oscillation stop circuit 36 Rectifier diode 37 Zener diode 38 Stop transistor 39 Stop Condenser 41 Main capacitor 62a Partition plate 73, 74 Groove 75 Convex part

Claims (5)

[Claims] 1. An oscillation transformer for charging a main capacitor of a strobe circuit, comprising at least a primary coil and a secondary coil inductively coupled to the primary coil, wherein a charging operation is automatically performed between the secondary coils. In an oscillation transformer connected to an intermediate output terminal used for stopping, an intermediate part of a secondary coil to be connected to the intermediate output terminal is cut into two parts, and each end of the cut secondary coil is connected to each other. An oscillation transformer connected to the intermediate output terminal from different directions. 2. An oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil and a secondary coil inductively coupled to the primary coil are wound around a bobbin, respectively, and a charging operation is performed between the secondary coils. In the oscillation transformer connected to an intermediate output terminal used for automatically stopping the motor, the intermediate output terminal is an L-shaped conductive member, and is fixed such that this corner is embedded in a bobbin. Cutting the middle of the secondary coil to be connected to the intermediate output terminal into two parts, and cutting each end of the cut secondary coil to a part of the intermediate output terminal projecting from the bobbin at a right angle to each other. An oscillation transformer characterized by being connected. 3. An oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil and a secondary coil inductively coupled to the primary coil are wound around a bobbin, respectively, and a charging operation is performed between the secondary coils. In an oscillation transformer to which an intermediate output terminal used to automatically stop the secondary coil is connected, the middle of a secondary coil to be connected to the intermediate output terminal is cut into two, and each end of the cut secondary coil is cut off. , Connected to the intermediate output terminal from different directions, and a partition plate is provided between each end of the secondary coil extending from the intermediate output terminal. 4. An oscillation transformer for charging a main capacitor of a strobe circuit, wherein at least a primary coil and a secondary coil inductively coupled to the primary coil are wound around a bobbin, respectively, and a charging operation is performed between the secondary coils. In the oscillation transformer connected to an intermediate output terminal used for automatically stopping the motor, a protrusion is provided near the intermediate output terminal of the bobbin, and two intermediate portions of the secondary coil to be connected to the intermediate output terminal are provided. And one end of the cut secondary coil is entangled with the protrusion, and then connected to the intermediate output terminal, and the other end is connected to the intermediate output terminal from a direction different from the one end. An oscillation transformer, characterized by being connected to: 5. The intermediate output terminal according to claim 1, wherein each of the cut ends of the secondary coil is connected to the intermediate output terminal by being entangled with the intermediate output terminal and then soldered. The oscillation transformer according to any of the above.