JPS61195596A - Emergency lamp switching circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] This invention operates an emergency power supply to convert a DC/AC conversion circuit (an inverter and an oscillation transformer) during a power outage of an AC power supply.
This invention relates to an emergency light switching circuit configured to start emergency lighting by operating the emergency light switching circuit.

[Background technology]

Regarding the emergency light switching circuit, the applicant has already proposed a hybrid switching type emergency light switching circuit for the purpose of preventing welding of the relay contacts for switching on the secondary side of the inverter (Japanese Patent Application No. 158683/1983). (see issue).

Emergency lighting equipment is stipulated by the Building Standards Act to be able to remain effectively lit for 30 minutes or more in an atmosphere of 140°C.

In the previous application, in an atmosphere of 140℃, AC lighting - AC power outage -> power outage detection - delayed operation (200 to 300m5) -> DC
It has the following operating modes: oscillation, inverter operation, and emergency lighting.

In this case, the relay contacts on the secondary side of the inverter are switched within the aforementioned delay time (200 to 300 ma), and then power is supplied to the primary side of the inverter and the discharge lamp is lit. The reason for the delay is to prevent high frequency from being applied when the relay contacts chatter.

In this hybrid switching method, the delay time (2
00 to 300 ms) in an atmosphere of 140°C.
When switching from DC to DC, the discharge lamp is temporarily turned off. That is, when DC lighting is performed, DC self-starting (starting from an unlit state) is performed instead of switching lighting.

Therefore, upon starting, a large starting voltage determined by the mercury vapor pressure of the discharge lamp in a 140° C. atmosphere is required.

The following table shows the relationship between the inverter secondary output voltage of each lamp FL2O3 and FL32S and the allowable delay time for normal switching at that voltage.

Table Secondary output voltage/delay time As you can understand from this table, the delay time is 200 to 300.
ms, each lamp has 580 [V),
A large output voltage of 570 (V) is required.

For this reason, if a hybrid switching system is adopted in a conventional general in-harter uni-soto, the emergency lighting will not work as expected in a 140'C atmosphere.

Therefore, we focused on the switching characteristics between AC lighting and DC lighting, and
In Japanese Patent Application No. 59-266031, the applicant describes the delay time T of the hybrid switching system. At room temperature, the switching time on the secondary side of the relay is set to be sufficiently longer than the switching time TRY2.
In the case of high-temperature lighting in an atmosphere of 140°C, the delay time is T.

is the time T for the ions in the lamp tube to disappear or for the lamp to go out. It is proposed to make it shorter than H.

TRv□<<70 (at room temperature) To <'rcH (at high temperatures such as 140°C) However, generally the switching time TRY2 is 10 to 20 ma, and the time TC for the ions in the tube to disappear or for the lamp to go out
I+ is less than 30m5 from the table.

Therefore, especially at high temperatures such as 140°C, the delay time T. It is fully conceivable that the switching time TRY□ will be shorter than the switching time TRY□, and the relay contact, which is a basic element of the hybrid switching system, will not cause chattering in an atmosphere of 140℃, and it is difficult to ensure a delay time T0 that is longer than the bounce time. Otherwise, there is a risk of welding to the relay contacts.

Furthermore, if the condition of TRY□<<T o<T cH is satisfied at each temperature, there will be no problem with welding of the relay contacts, but the switching time T, 17□ and the time for the ions in the tube to disappear or for the lamp to go out Delay time T from the value of TcH. The permissible time width for is approximately 10m5
However, it is technically difficult to put it into practical use considering variations in components and temperature changes.

[Purpose of the invention]

The purpose of this invention is to solve the problems of the conventional example, and
To provide an emergency light switching circuit capable of stably switching from AC lighting to DC lighting even in a high temperature state such as a 0° C. atmosphere.

[Disclosure of the invention]

The emergency light switching circuit of the present invention includes a DC/AC conversion circuit that is driven by an emergency power source and connected to a discharge lamp based on the operation of a power outage detection means, and a DC/AC conversion circuit that is driven by an emergency power source and connected to a discharge lamp based on the operation of a power failure detection means, and a It is equipped with a control circuit that controls the output voltage of the conversion circuit to be high or low.

The effects of the configuration of this invention are as follows.

fal At room temperature, the output voltage of the orthogonal/alternating current conversion circuit is suppressed to the necessary minimum, so that the orthogonal/alternating current conversion efficiency is maintained in a sufficiently high state.

(bl) As the temperature increases, the output voltage of the orthogonal/alternating current conversion circuit increases, so that switching from AC lighting to DC lighting of the discharge lamp is performed stably.

Example A basic embodiment of this invention will be explained based on FIG.

FIG. 1 is a block diagram.

In FIG. 1, 1 is an AC power supply, 2 is a ballast, 3 is a lamp, 4 is a relay as a power failure detection means, 5 is a relay contact, 6 is a charging circuit, 7 is a secondary battery as an emergency power source, 8
9 is an inverter as an orthogonal/alternative conversion circuit; 10 is a temperature detection section;
11 is a secondary voltage control section.

The temperature detection section 10 and the secondary voltage control section 11 constitute the "control circuit A that controls the output voltage of the orthogonal/alternating current conversion circuit to be high or low in response to changes in the detected temperature." It consists of

Delay time T of delay circuit 8. is set at 200 to 300 nia, which is technically easy to set.

The temperature detection unit 10 outputs a higher-level signal to the secondary voltage control unit 11 as the ambient temperature is higher.
The higher the input voltage, the higher the secondary output voltage of the inverter 9.

Next, the operation will be explained.

(i) In normal times, the relay contact 5 is connected to the normally closed contact NC, and the lamp 3 is turned on via the ballast 2 using the AC power supply 1 as a power source.

Further, the charging circuit 6 is operated by the AC power source 1, and the secondary battery 7 is being charged.

(11) In the event of a power outage, the power outage detection relay 4 operates to switch the relay contact 5 to the normally open contact NO side, and the power outage detection switching element of the delay circuit 8 operates to drive the delay circuit 8.

- The delay circuit 8 operates the inverter 9 when a predetermined delay time has elapsed, and the lamp 3 is activated by its high frequency output.
lights up.

(iii) As the ambient temperature rises, the output level of the temperature detection section 10 rises, causing the output voltage of the inverter 9 to rise via the secondary voltage control section 11. Therefore, even under high-temperature conditions such as a 140° C. atmosphere, it is possible to stably switch from AC lighting to DC lighting without causing the ions in the tube to disappear or the lamp to go out.

A concrete first example will be described based on FIG. 2. FIG. 2 is a circuit diagram of the emergency light switching circuit in a power outage state.

Push-pull inverter 12 via choke coil L
is connected to an input terminal IN which is connected to an AC power source.

The push-pull inverter 12 is one of the oscillation transformers OT.
A series circuit of a secondary winding N and a transistor Q, a series circuit of a primary winding N2 of an oscillating transformer OT and a transistor Q2,
Feedback winding N4 of the oscillation transformer OT connected between the hearths of transistors Q, , Q, transistors Ql, Q,
A main resonant capacitor C8 connected between the collectors of the main resonant capacitor C8, a switching element SI connected in parallel to the main resonant capacitor C8, a series circuit of the resonant capacitor C1, a switching element S2, a series circuit of the resonant capacitor C2, a switching element S, Series circuit of resonant capacitor C3, each transistor Q+, base of Q2 and primary winding NJ
A resistor R connected between ilN+ and the positive terminal of Nz
+, Rz.

The secondary winding N3 of the oscillator 1 to the lance OT is connected to the output terminal OUT to the lamp.

The push-pull inverter 12 and the oscillation transformer OT constitute an orthogonal/alternate conversion circuit B according to the configuration of the invention.

The switching elements St, Sz, and S3 are configured to be turned off and on by the secondary voltage control section 13. The trigger levels of each switching element S1°Sz, Si are different, and are configured to be turned off sequentially as the temperature detected by the temperature detection unit 14 rises.At room temperature, all switching elements S1, S+, S2.
S3 is on.

Temperature detection unit 14. Secondary voltage control unit 13, switching elements S, ~S3, and resonant capacitors CI~C3 are configured according to the configuration of the invention [to adjust the output voltage of the DC/AC conversion circuit according to high/low changes in the detected temperature. Control circuit A that controls high and low
It consists of

Next, the operation will be explained.

■ At room temperature, the parallel combined capacitance of the main resonant capacitor C6 and the three resonant capacitors C, C, C3 is large, and the time constant determined by this and resistor R1 or resistor R2 is large. Oscillation voltage is low. Therefore, the output voltage of the secondary winding N3 of the oscillation transformer OT is also low. In this case, the orthogonal/alternate conversion efficiency of the inverter 12 is maximum.

(2) When the ambient temperature rises, the secondary voltage control section 13 turns off the switching element S based on the operation of the temperature detection section 14. The resonant capacitance is the parallel combined capacitance of the main resonant capacitor C0 and the two resonant capacitors C2 and C3, and is
decreases compared to the case of . As a result, the time constant of the inverter 12 becomes slightly smaller.

The output voltage of the oscillation transformer OT increases.

That is, the lamp is turned on at a voltage commensurate with the ambient temperature.

(2) When the ambient temperature further rises, the secondary voltage control unit 13 controls the switching element 31. based on the operation of the temperature detection unit 14. Turn off S2. The resonant capacitance is a parallel combined capacitance of the main resonant capacitor C8 and one resonant capacitor C3, and is smaller than in case (2). As a result, inverter 1
The time constant of 2 is further reduced, and the output voltage of the oscillation transformer OT is further increased.

In this case as well, the lamp is lit at a voltage commensurate with the ambient temperature.

■ When the ambient temperature rises to a certain degree, the temperature detection section 14
Based on the operation, the secondary voltage control section 13 turns off all the switching elements S+, Sz, and Ss. The resonant capacitance is only the main resonant capacitor c0, which is smaller than in case (2).

As a result, the time constant of the inverter 12 decreases, the output voltage of the oscillation transformer OT increases significantly, and the lamp is lit at a voltage commensurate with the high ambient temperature.

In this case, the orthogonal/alternate conversion efficiency of the inverter 12 is minimized.

As described above, switching between AC lighting and DC lighting can be performed stably even in a 140° C. atmosphere. Further, at room temperature, the output voltage of the inverter 12 can be suppressed to the necessary minimum, and the orthogonal/alternating current conversion efficiency can be maintained in a sufficiently high state.

A specific second embodiment will be described based on FIG. 3.

In FIG. 3, the same reference numerals used in FIG. 2 according to the previous embodiment refer to the same parts as those indicated by the reference numerals.

Unless otherwise specified, this embodiment and the first embodiment have the same configuration regarding connection relationships.

The structure in which this embodiment differs from the first embodiment is as follows.

Switching element S1 in the first embodiment - Series circuit of resonant capacitor C1, switching element S2 - Series circuit of resonant capacitor C2, switching element S, -
There is no series circuit of resonant capacitor C3.

Instead, switching elements Sw, to Sw4 are inserted between each of the plurality of intermediate taps and negative terminals of the secondary winding N5 of the oscillation transformer OT and the negative electrode of the lamp. The switching element Sw among these switching elements sW and ~Sw4.

is on at room temperature, and switching elements Sw2 to Sw4 are off at room temperature.

A2 is "a control circuit that controls the output voltage of the orthogonal/alternating current conversion circuit to be high or low in response to changes in the detected temperature."

The rest of the configuration is the same as that of the first embodiment, so a description thereof will be omitted.

Next, the operation will be explained.

As the ambient temperature increases, ■ Switching elements 3w, SW, SW.

is off and switching element Swz is on ■ Switching element 3w, Swz, 3w4 is off and switching element SW3 is on ■ Switching element S
w+, 3w2, 3w3 are off, switching element Sw
4 are sequentially switched to the on state, and the output voltage to the lamp increases accordingly.

〔Effect of the invention〕

According to this invention, there are the following effects.

+a) At room temperature, the output voltage of the orthogonal/alternating current conversion circuit can be suppressed to the necessary minimum, and the orthogonal/alternating current conversion efficiency can be maintained at a sufficiently high level.

(bl) As the temperature rises, the output voltage of the orthogonal/alternating current conversion circuit is increased to stably switch the discharge lamp from AC lighting to DC lighting.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an emergency light switching circuit according to a basic embodiment of the present invention, Fig. 2 is a circuit diagram of the emergency light switching circuit of the first embodiment in a power outage state, and Fig. 3 is a concrete diagram of the emergency light switching circuit according to the first embodiment. FIG. 3 is a circuit diagram of the second embodiment in a power outage state. 3... Lamp (discharge lamp), 4... Power outage detection relay (
power outage detection means), 7... secondary battery (emergency power supply), 9
．． 12...Inverter, 10.14...Temperature detection section, OT...Oscillation transformer, A, A,, A2...Control circuit, B...Orthogonal/AC conversion circuit

Claims (1)

[Claims] A DC/AC conversion circuit is driven by an emergency power supply and connected to the discharge lamp based on the operation of a power outage detection means, and the output voltage of the DC/AC conversion circuit is increased or decreased in response to changes in detected temperature. An emergency light switching circuit equipped with a control circuit that controls the