JPS599214Y2 - strobe flash device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a strobe flash device, and more particularly to a strobe flash device that can reliably emit light at a relatively low voltage.

In order to automatically control exposure in a strobe flash device, it is effective to connect a control rectifying element SCR in series with the flash bulb without power loss, but the voltage required for light emission due to this element SCR is The voltage rises by about 20 to 30V, which has the disadvantage of requiring a high-voltage ρ power source.

Additionally, in general, as the flashbulb ages, the voltage required to emit light increases, so there is a drawback that the light emission becomes uncertain.

The present invention solves this problem by connecting the above-mentioned capacitor from the power supply side to the ground side in connection with this trigger switch, and superimposing the potential of this capacitor on the potential of the main capacitor, which acts on the flash bulb. This device uses a relatively low-voltage power source to ensure that the flash bulb emits light.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In Figure 1, C is the main capacitor connected to the power supply that supplies the discharge current, X is the flash bulb such as a xenon tube, and SCR.
is a control rectifier connected in series with it, L is a trigger coil, S is a trigger switch that turns on in conjunction with the shirt button, etc., and is connected in series with resistor R and coil L, and the other end is connected to ground. .

C1 is a capacitor for charging the trigger current and is connected between the resistor R and ground.

In the trigger circuit consisting of the trigger coil L and capacitor C1, a point A between the trigger switch S and the coil L and the real side of the flash bulb X are connected by a capacitor 2 for introducing a light emission auxiliary voltage. Connect with high resistance 1 between the terminal and the ground side.

Next, the operation of this device will be explained.

The capacitor C1 is charged with a trigger charge from the power supply voltage (2) via the resistor R, while the capacitor 2 is charged from the power supply voltage (2) through the resistor R to the same voltage V1 as the power supply voltage.

When the switch S is turned on, the charge in the capacitor C1 is discharged through the coil L and the switch S, and a high voltage is induced in the secondary coil of the coil L, which triggers the flashbulb X.

On the other hand, the positive side of capacitor 2 is connected to the ground side via switch S, but since resistor 1 has a high resistance, it does not discharge immediately, so the potential of capacitor 2 is superimposed on the potential of main capacitor C, and the flash V at the terminal of ball X
A potential of +V1=2V, that is, a voltage completely twice as high as the power supply voltage is applied to assist the light emission.

At this time, the potential of the capacitor 2 acts as a reverse bias on the element SCR, but since the capacitance of the capacitor 2 is small, it acts only momentarily and does not interfere with the operation of the element SCR.

In the embodiment described above, the capacitor 2 is connected from the power supply side to the ground side using the trigger switch S, but this is not necessarily the case.The trigger switch S, that is, another switch that is linked to the shirt button, can be used to switch the capacitor 2. Good too.

As described above, in this invention, the voltage applied to the flash bulb is increased when the flash bulb is triggered, so the light emission is assisted, a relatively low voltage current can be used, and even old flash bulbs can reliably emit light. In addition, it is possible to use a ball with a higher pressure than in the past.

[Brief explanation of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. C: Main capacitor, X: Flash bulb, SCR: Element, L: Trigger circuit coil, 2: Capacitor.

Claims (1)

[Scope of utility model registration request] A main capacitor C that supplies a discharge current is connected in parallel to the power supply, and a series circuit of a flash bulb X and an element SCR is connected in parallel to this main capacitor C, and a high resistance 1 is connected in parallel to this element SCR. In addition, a series circuit consisting of a resistor R and a capacitor C1 for charging the trigger current is connected in parallel to the main capacitor C, and a connection point between the resistor R and the capacitor C1 for charging the trigger current, this flash bulb and the element is connected to the main capacitor C. The primary side of the trigger coil L and a capacitor 2 for introducing the light emitting auxiliary voltage are connected in series between the connection point of the SCR and the connection point of the primary side of the capacitor 2 and the trigger coil, and the ground. When the trigger switch S is connected and the trigger switch S is closed, the capacitor 2 is connected from the power supply side to the ground side, the potential of this capacitor 2 is superimposed on the potential of the main capacitor C, and the voltage acting on the flash bulb X is A strobe flash device characterized by having a voltage higher than that of a power supply to assist in emitting light.