JPS6232000Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a two-lamp light source device that has a spare lamp in addition to the main lamp.

Generally, when the lamp in use breaks while using the light source device for an endoscope, if you go out of your way to replace it with a separately prepared spare lamp, it will take time to replace it, and during that time the patient will be In addition to causing unnecessary pain to the patient, it is also dangerous because the condition of the endoscope and treatment instruments is unknown due to the lack of illumination. Therefore, many devices have come into use that, when the lamp in use breaks, can immediately turn on a spare lamp and continue illumination simply by flipping a switch.

However, this method had the disadvantage that if the spare lamp was already burnt out, it would not turn on even if the switch was turned on, and it would take more time to replace it with a new lamp.

Therefore, a method has been proposed that uses two diodes and connects them in series in opposite directions to configure a circuit that can light a neon tube and detect and display the presence or absence of a break in a spare lamp (in practice). Publication No. 55-131099). However, since this method requires at least two diodes, the circuit configuration becomes complicated and assembly is troublesome. Furthermore, as more electrical components are used, the reliability thereof decreases. Also,
There were drawbacks such as high cost.

This invention was made with attention to the above circumstances,
The purpose is to provide a two-lamp light source device that can detect whether or not a spare lamp is disconnected with a simple configuration and can improve reliability.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

A transformer 2 is connected to both ends of the commercial power source 1, with the intermediate point and one end of the transformer 2 serving as lamp lighting voltage terminals B and C, and the other end of the transformer 2 serving as a discharge lamp lighting voltage terminal A. A first lamp 4 and a second lamp 5 are connected in parallel between the lamp lighting voltage terminals B and C via a changeover switch 3 as a changeover means. In other words, changeover switch 3
connects one lamp lighting voltage terminal B of commercial power supply 1 to 2
the first lamp 4 and the second lamp 4.
The operating voltage is selectively supplied to the lamps 5. Further, a first resistor 6 and a second resistor 7 for discharging are connected to the terminals on the switch 3 side of each lamp 4, 5, respectively, and the other end of each resistor 6, 7 is a discharge lamp lighting voltage terminal. Commonly connected to A. Furthermore, the first lamp 4 and the first
A neon tube 8 is connected as a display discharge lamp between the connection point of the resistor 6 and the connection point of the second lamp 5 and the second resistor 7.

Here, the rating of the first and second lamps 4 and 5 is 150W at 15V, the first and second resistors 6,
7 is 100 kΩ, and the lighting voltage of the neon tube 8 is 60 V. The operation of the two-lamp light source device having the above configuration will be described below.

Therefore, if the changeover switch 3 is turned to the first lamp 4 side as shown in the drawing, the neon tube 8 is supplied with 100V via the first resistor 6 for discharge.
The voltage of the commercial power supply 1 is applied. However, since the impedance of the transformer 2 is significantly smaller than the impedance (100 kΩ) of the first resistor 6,
The terminal voltage of lamp 4 becomes 15V. Also, if the spare second lamp 5 is not disconnected at this time, the impedance of this second lamp 5 is 1.5.
The impedance is approximately Ω, which is significantly smaller than the impedance of the second resistor 7 (100 kΩ). Therefore, the terminal voltage of the second lamp 5 becomes approximately zero value. Therefore, the voltage applied to both ends of the neon tube 8 becomes less than the lighting voltage (15V), and the neon tube 8 does not light up. This shows that the spare second lamp 5 is not disconnected.

On the other hand, if the second lamp 5 is disconnected, the impedance value of the second lamp 5 becomes infinite, and 100V of the commercial power supply 1 is applied to the neon tube 8 through the second resistor 7, and the neon tube 8 is turned off. Since the voltage applied to the tube 8 exceeds the lighting voltage and reaches 85V, the neon tube 8 lights up. This indicates that the spare first lamp 5 is disconnected. Therefore, the broken second lamp 5 can be replaced in advance.

Note that the same operation as described above also occurs when the changeover switch 3 is switched to turn on the second lamp 5. In other words, when the first spare lamp 4 is not disconnected, the neon tube 8 does not light up, and when the first lamp 4 is disconnected, the neon tube 8 is not lit.
lights up to indicate whether there is a disconnection.

Note that the transformer 2 in the above embodiment may be of a separate type in which the primary winding and the secondary winding are insulated.

As explained above, the present invention has a simple circuit configuration that can detect disconnection of a spare lamp in advance, and the number of parts is reduced, making assembly work easier and reducing costs. Furthermore, unlike conventional devices, diodes are not required, and electrical components can be omitted, thereby improving operational reliability and durability.

[Brief explanation of the drawing]

The drawing is a diagram showing a circuit configuration of an embodiment of the present invention. 1... Commercial power supply, 2... Transformer, 3... Changeover switch, 4... First lamp, 5... Second lamp, 6... First resistor, 7... Second resistor, 8
...Neon tube.

Claims (1)

[Scope of utility model registration request] A power supply having a lamp lighting voltage terminal and a discharge lamp lighting voltage terminal, a switching means connected to one end of the lamp lighting voltage terminal of this power supply to switch and supply operating voltage to two paths, and a switching means connected to each path of the switching means, respectively. A first terminal having one end connected to the other end and the other end commonly connected to the other end of the lamp lighting voltage terminal.
and a second lamp, first and second resistors each having one end connected in series to the first and second lamps, and each other end connected in common to the discharge lamp lighting voltage terminal of the power source, and the lamp. A two-lamp light source device comprising: and an indicator discharge lamp inserted between a connection point of a resistor.