JPS5923360Y2 - Discharge lamp starting and power supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for starting and powering a gas and/or vapor discharge lamp having two electrodes.

The device comprises two input terminals for connection to an alternating current voltage source with a frequency of less than 100 Hz, the two input terminals being connected at least to the stabilizing inductor and the discharging inductor during starting and powering the discharge lamp. the two electrodes of the discharge lamp are interconnected by a starter having a first semiconductor switching element, the first semiconductor switching element being connected in parallel to the branch with the semiconductor switching element; A control circuit is provided, the control circuit having at least a first capacitor and a starter auxiliary transistor shunting at least the first capacitor, the base of the auxiliary transistor being connected to the control circuit;
That is, it is connected to a connection point between a first resistor and a second capacitor connected in series, and these first resistor and second capacitor are connected in parallel to a branch having a first semiconductor switching element.

A device of this type is known, for example, from FIG. 1 of US Pat. No. 3,875,459.

The advantage of this device is that the auxiliary transistor stops the actuation of starting the discharge lamp after a certain period of time if the discharge lamp does not attempt to light up.

However, a drawback of this device is that the voltage peaks generated for starting the discharge lamp exhibit a relatively large and fairly constant amplitude.

This means that the first semiconductor switching element is
It is required that it must be able to withstand these voltage peaks in the non-conducting state.

Yet another disadvantage of this device is that the discharge lamp will not ignite if the relatively large amplitude of the voltage peak is too small to start the discharge lamp.

Purpose of the invention The purpose of the invention is that the first semiconductor switching element is rated for a relatively low allowable voltage for a rather long period of time, but when it is difficult to start the discharge lamp, one or several large amplitude switching elements can be used. The object of the present invention is to provide a device of the type described above which generates several short-term voltage peaks.

The present invention is a device for starting and powering a gas and/or vapor discharge lamp comprising two electrodes and having a frequency of 100
a series circuit comprising at least a stabilizing inductor and a discharge lamp, comprising two input terminals for connection to an alternating current voltage source of less than Hz, the two input terminals being connected during starting and powering of the discharge lamp; interconnecting the two discharge lamp electrodes to a diode bridge; interconnecting the two output terminals of the diode bridge by a starter having a first semiconductor switching element; A control circuit for a first semiconductor switching element is provided in parallel with the branch having a first semiconductor switching element, the control circuit having at least a first capacitor and at least an auxiliary transistor of the starter which shunts the first capacitor; 1 capacitor is provided in a branch connecting the control electrode of the first semiconductor switching element to the main electrode of the first semiconductor switching element, and when the voltage across the terminals of the first capacitor exceeds a threshold value, the first semiconductor switching element conducts, and connects the base of the auxiliary transistor to a control circuit, that is, to the connection point between the first resistor and the second capacitor;
The resistor and the second capacitor are connected in series with each other and in parallel with the branch with the first semiconductor switching element, and the series-connected circuit with at least the first resistor and the second capacitor is powered by a diode bridge. In the discharge lamp starting and power supply device, the base of the auxiliary transistor is connected to the connection point of the first resistor and the second capacitor via a Zener diode,
The two discharge lamp electrodes are connected to each other by a third capacitor, and a second inductor is provided in a connection circuit connecting the discharge lamp electrodes to the first semiconductor switching element, and the first semiconductor switching element is switched. In this case, the second inductor in conjunction with the third capacitor provides a transient voltage between the discharge lamp electrodes that is higher than the supply voltage between the input terminals, so that after a certain time a higher transient voltage is applied to the discharge lamp electrodes. In other words, the first semiconductor switching element is made conductive with a delay, and this delay is caused by charging the second capacitor to reach the Zener voltage of the Zener diode. shall be.

The advantages of the device of the present invention are as follows.

This means that a voltage-sensitive threshold element (Zener diode) in the control circuit of the auxiliary transistor causes the first
The instant at which the semiconductor switching element starts conducting can be changed.

This allows varying the degree to which the voltage between the discharge lamp electrodes can rise during lamp startup.

As a result, the moment when the first semiconductor switching element starts conducting is somewhat delayed, and as a result, the third capacitor and the second
The voltage rise across the series circuit with the inductor and therefore the voltage across the electrodes of the discharge lamp used for starting increases.

The present invention not only uses an auxiliary transistor to stop the starting operation of the discharge lamp by shorting the first capacitor when the discharge lamp obviously does not intend to light up, but also prevents the starting operation of the discharge lamp. It is based on the idea of using auxiliary transistors in between.

This is achieved by activating the auxiliary transistor one or more times for a short time before the end of the starting operation, thereby preventing the charging of the first capacitor of the control circuit of the semiconductor switching element.

This means that the conductive operation of the auxiliary transistor continues until the first capacitor obtains a voltage that allows the semiconductor switching element to conduct.

As is clear from the foregoing, this delay results in a significant increase in the lamp voltage.

However, after the device is switched on, it takes some time for the auxiliary transistor to start conducting.

The reason for this is the presence of a voltage sensitive threshold element in the control circuit of the auxiliary transistor.

If, after a period of time, the second capacitor has been charged to such an extent that it conducts the auxiliary transistor, there is a delay in rendering the first semiconductor switching element conductive.

British Patent No. 1,208,489 describes the rise in the voltage between the electrodes of a discharge lamp during the starting operation.

However, in this case, the instant at which the semiconductor switching element becomes conductive does not change.

The discharge lamp can be, for example, a discharge lamp without a preheating electrode, for example a high-pressure metal vapor discharge lamp.

Preferably, the discharge lamp is a discharge lamp provided with a preheating electrode, for example a low-pressure mercury vapor discharge lamp.

In this case, the current flowing through the semiconductor switching element during the starting operation can be used to preheat the discharge lamp electrode.

The first semiconductor switching element can be composed of, for example, two thyristors connected in antiparallel.

Further, the first semiconductor switching element may be, for example, a triac, that is, a semiconductor switching element having bidirectional thyristor characteristics.

In a preferred embodiment of the invention, a diode bridge is provided between the discharge lamp electrode and the first semiconductor switching element, and the first semiconductor switching element is a transistor arranged in the central branch of the diode bridge.

The advantages of this embodiment are as follows.

That is, only simple semiconductor switching elements are required and, moreover, a large number of small voltage peaks can be generated in the discharge lamp during each half cycle of the supply voltage.

The voltage-sensitive threshold element of the control circuit of the auxiliary transistor can be, for example, a neon glow discharge lamp.

In the present invention, the voltage sensitive threshold element is a first Zener diode.

In this case, for example, there is an advantage that the threshold voltage of the threshold element hardly changes over time.

In another preferred embodiment of the present invention, the control circuit for the auxiliary transistor includes a series circuit in which a resistor, a first diode, a first Zener diode, and a fourth capacitor are connected in series in this order; The conduction directions of the diode and the Zener diode face each other, and the series circuit of the first diode, the first Zener diode, and the fourth capacitor is shunted by the series circuit of the second resistor and the second capacitor. Each of the four capacitors is shunted by a resistor.

The advantages of this embodiment are as follows.

That is, this special control circuit for the auxiliary transistor makes it possible to switch the auxiliary transistor into a conducting state and a non-conducting state multiple times during each half cycle of the supply voltage.

This is done as follows.

Via the first and second resistors, a second capacitor can initially be charged, which then conducts the auxiliary transistor via the first diode and the blocking direction of the first Zener diode.

Since the voltage across the branch circuit having the first semiconductor switching element exhibits oscillation, the voltage across the series circuit of the second resistor and the second capacitor immediately drops below the threshold voltage of the first Zener diode. do.

As a result, the auxiliary transistor becomes non-conductive.

Since the frequency of the voltage across the branch with the first semiconductor switching element is generally higher than the frequency of the power supply voltage,
The previously described operation of switching the auxiliary transistor into a conducting and non-conducting state several times during each half-cycle of the supply voltage can be repeated.

The last described embodiment can be further improved by adding a non-capacitive voltage divider to the control circuit of the auxiliary transistor.

This voltage divider is connected in parallel to the branch with the first semiconductor switching element, and the tap of the voltage divider is connected via the second diode to the interconnection point of the first diode and the Zener diode.

The direction of conduction of the second diode is directed towards said interconnection point.

The advantages of this improvement are as follows.

That is, if the voltage across the first semiconductor switching element reaches a high value very quickly, current flows through the non-capacitive voltage divider and the second diode in the blocking direction of the Zener diode.

This current immediately causes the auxiliary transistor to conduct.

At this time, the first capacitor is short-circuited to prevent the first semiconductor switching element from becoming conductive again.

That is, assuming that the first semiconductor switching element configured as an auxiliary transistor becomes conductive at this time,
This switching element may be damaged by such high voltages between its main electrodes.

A preferred embodiment of the invention comprises a first capacitor;
A second voltage sensitive threshold element is connected in a branch connected in parallel to the first semiconductor switching element.

The advantages of this embodiment are as follows.

That is, the second voltage sensitive threshold element provides an instantaneous delay for the first semiconductor switching element to become conductive, completely independent of the auxiliary transistor and its control circuit.

As a result, the voltage of the discharge lamp rises slightly higher.

Yet another advantage of the second voltage threshold element is that it can also be used to stop the starter operation as soon as the discharge lamp has started.

For this purpose, the threshold voltage must be greater than the operating voltage of the discharge lamp.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 shows an electrical circuit of an embodiment of the device of the present invention.

FIG. 1 also shows the discharge lamp attached to this circuit.

In the figure, 1 and 2 are terminals for connection to a 220 V, 50 Hz AC voltage source.

Connect one end of the inductive ballast 3 to the terminal 1.

If necessary, a capacitive ballast having an overall capacitive characteristic can be used instead of a series circuit of a coil and a capacitor.

The other end of the ballast 3 is connected to the preheating electrode 4 of the low pressure mercury vapor discharge lamp 5.
Connect to.

Reference numeral 6 indicates a second preheating electrode of the discharge lamp 5.

Connect electrode 6 to input terminal 2. The ends of the electrodes 4 and 6 that are closer to the input terminals 1 and 2 are interconnected by a capacitor 7.

The other ends of electrodes 4 and 6 are interconnected by a capacitor 8.

Further, the capacitor 8 is shunted by a series circuit of an inductor 9 and diode bridges 10 to 13.

This inductor 9 cooperates with the capacitor 8 to
and 6 to generate a transient voltage greater than the supply voltage supplied between terminals 1 and 2.

This is explained in detail in Japanese Patent Publication No. Sho 46-17625, a high-frequency starting type gas discharge lamp lighting device.

The inductor 8 shown in FIG. 1 of this publication corresponds to the inductor 9 described above.

The second feature of this publication is the generated voltage E. is the power supply voltage E
.

It is shown that the value is higher than that.

The diode bridge comprises four central branches.

The first central circuit consists of a resistor 20, a transformer winding 21, and an NPN)
It has a series circuit with the main electrode of the transistor 22.

The other winding 23 of the transformer is connected between the base and emitter of the transistor 22.

The second central branch of the diode bridges 10-13 comprises a series circuit of a resistor 24, a Zener diode 25 and a capacitor 26.

A connection point between Zener diode 25 and capacitor 26 is connected to one end of resistor 27.

The other end of resistor 27 is connected to the base of transistor 22 via a bidirectional breakdown element 28 .

A resistor 29 is connected between the base and emitter of transistor 22.

The connection point between resistor 27 and breakdown element 28 is connected to the collector of NPN type auxiliary transistor 30.

The emitter of this auxiliary transistor is connected to diodes 12 and 13 of the diode bridge.

The third central branch of the diode bridge connects the resistor 31 and the first
It includes a series circuit of a diode 32, a Zener diode 33, and a capacitor 34.

Capacitor 34 is shunted by resistor 35.

Further, the series circuits 32, 33, 35 are shunted by a parallel circuit of a capacitor 37 and a resistor 38, and a series circuit of a resistor 36.

The fourth central circuit of the diode bridges 10-13 has a resistive voltage divider comprising a series circuit of a resistor 39 and a resistor 40.

A connection point between resistor 39 and resistor 40 is connected to one end of diode 41.

The other end of this diode is connected to the connection point between diode 32 and Zener diode 33.

3 diodes 32.33. The conduction directions of 41 are all toward their interconnection points.

The connection point between the inductor 9 and the diode 10 and the connection point between the diode 13 and the electrode 6 are interconnected by a spike suppressor 42 .

The circuit described above operates as follows.

When terminals 1 and 2 are connected to a 220 V, 50 Hz AC voltage source, sufficient instantaneous voltage across terminals 1 and 2 causes circuit 1 to
, 3, 9, 10° 24.25, 26.13 to terminal 2
to, or circuit 2,6゜11.24,25,26,1
Current flows to terminal 1 via 2, 9.3.

As a result, when capacitor 26 obtains a voltage that exceeds the breakdown value of threshold element 28, it discharges and transformers 21, 23 cause transistor 22 to become fully conductive.

Current therefore begins to flow through the first central branch or branch 20, 21.degree. 22 of the diode bridge.

This current preheats the electrodes 4 and 6 of the discharge lamp 5.

When this current reaches a certain value, driving of the transistor 22 is stopped.

Due to the delay caused by the flow of charge carriers from the transistor, this transistor becomes non-conducting again after a short time.

While the transistor 22 is conducting, the capacitor 26 is partially discharged via the resistor 27 and the threshold element 28 and the resistor 29.

Due to the transistor 22 becoming non-conducting, the voltage across the capacitors 7 and 8 and therefore the voltage across the discharge lamp 5 increases.

However, during that time capacitor 37 is connected to resistors 31 and 36
After that, it will be charged slightly.

After perhaps several half-cycles of the supply voltage between terminals 1 and 2, the voltage on capacitor 37 reaches a certain relatively large value, after which current flows from resistor 31 through diode 32 in the blocking direction of diode 33. flows periodically, thereby starting to conduct the auxiliary transistor 30,
The series circuit of resistor 27 and capacitor 26 is short-circuited.

Of course, this allows the capacitor 26 to be partially discharged.

Therefore, this actually prevents capacitor 26 from being charged through resistor 24.

This delay in charging capacitor 26 delays the moment when transistor 22 becomes conductive, so that the circuit of capacitors 7 and 8 and inductor 9
2, the circuit becomes closed after some delay.

This results in an even greater increase in the voltage of these two capacitors 7 and 8 and thus a corresponding increase in the voltage of the discharge lamp 5.

If the voltage between the discharge lamp electrodes 4 and 6 suddenly becomes very high, a current immediately flows through the voltage dividers 39, 40 and the diode 41 in the blocking direction of the Zener diode 33, which quickly turns the transistor 30 into a conductive state. Switch to
Therefore, transistor 22 is prevented from becoming conductive further.

This is desirable.

The reason is that the transistor must not conduct further at high voltages at the main electrode that might destroy the transistor.

If the voltage between the lamp electrodes 4 and 6 suddenly increases, the spike suppressor 42 reduces this high voltage.

Therefore, the high voltage on transistor 22 is only present for a short period of time.

The withstand voltage of the transistor 22 generally depends on the temperature of the transistor.

Therefore, if the voltage across transistor 22 is somewhat moderate during the period just before the sudden high voltage, the heat dissipation in the transistor is also low and therefore the temperature of transistor 22 is also somewhat low, so that for a short period of time It can withstand relatively high voltages.

In a specific embodiment, inductor 3 is approximately 1.2 Henry.

The discharge lamp 5 is a low pressure mercury vapor discharge lamp of approximately 40W.

The capacitance of capacitor 7 is 22 nanofarads, and the capacitance of capacitor 8 is about 2.5 nanofarads.

The self-inductance of inductor 9 is approximately 0.2 millihenry.

The value of resistor 20 is approximately 27Ω, and the value of resistor 24 is approximately 18Ω.
To,! Q, the value of resistor 27 is approximately ICI, the value of resistor 29 is approximately 100 g, and the value of resistor 31 is approximately 390 g.
KQ and the value of resistor 35 is approximately 10, Q and the value of resistor 36 is approximately 6.8 K,! Q, and the value of resistor 38 is approximately 150Ω.

The value of resistor 39 is approximately 100 Ω, and the value of resistor 40 is approximately 3.9 K,! It is Q.

Condensers 26, 34, and 37 have capacities of 5.6 nanofarads, 3.3 nanofarads, and 6.8 microfarads, respectively.

The Zener voltage of the Zener diode 33 is about 22V, and the Zener voltage of the Zener diode 25 is about 150V.
It is V.

The breakdown voltage of threshold element 28 is approximately 28 µ and spike suppressor 42 responds to a voltage of approximately 680 µ at 1 mA.

The arrangement of the two capacitors 7 and 8 serves to protect the starter in case the electrodes of the discharge lamp 5 break during the starting operation.

That is, the sudden breakage of the electrode 4 or 6 of the discharge lamp 5
A voltage kick is generated, but this voltage kick is caused by the discharge lamp 5.
This is because it is attenuated by capacitors 7 and 8 which are connected in parallel.

An undamped voltage kick will destroy transistor 22.

The device described above causes the discharge light to flicker.
It is started without causing any problems.

Reliable lighting is obtained in the temperature range from 20°C to +70°C.

If the discharge lamp 5 does not light up for some reason, the voltage across the series circuit of the resistor 36 and the second capacitor 37 remains higher than the Zener voltage of the Zener diode 33, so the auxiliary transistor 30 prevents the starter from attempting further operation after a certain amount of time.

A major advantage of the device according to the invention is that the auxiliary transistor 30 has a second function.

This second function is performed by the capacitor 26 as described above.
during the starting operation.
A high voltage can be applied between the discharge lamp electrodes 4 and 6.

For a more detailed explanation, the instantaneous voltage e between the electrodes 4 and 6 of the discharge lamp 5 of FIG. 1 is shown in FIG. 2 as a function of time t.

Consider the following three cases.

(a) Discharge lamp 5 that is easy to start (b) Discharge lamp that is difficult to start 5 (C) Discharge lamp 5 that does not start Terminals 1 and 2 of FIG. 1 are connected at instant t.

shall be connected to the power supply.

Until the instant t1, only the parts of the starter designated 7 to 29 in FIG. 1 are in operation.

This means that the auxiliary transistor 30, together with its control circuit, does not yet influence the starting operation.

The time from to to tl is about 1.2 seconds.

At this time, the peak voltage between the discharge lamp electrodes is about 500V.

From the instants t1 to t2, the auxiliary transistor 30 is periodically switched into a conducting state and a non-conducting state.

As a result, the voltage between the discharge lamp electrodes 4 and 6 increases, as explained with reference to FIG.

The time from tl to t2 is approximately 0.1 seconds.

At this time, the peak voltage between the discharge lamp electrodes is about 800V.

After the instant t2, the auxiliary transistor 30 prevents the starter from operating.

At this time, a power supply voltage appears between the discharge lamp electrodes.

When the discharge light 5 lights up, the starter operation is immediately stopped,
The voltage between the discharge lamp electrodes 4 and 6 immediately becomes equal to the operating voltage of the discharge lamp.

At this time, the starter is not operated due to the Zener diode 250 action.

The reason for this is the threshold voltage (1
50V) is higher than the operating voltage of the discharge lamp 5.

In the case of the above-mentioned discharge light (a) which is easy to turn on, the starting operation is instantaneous t.

and 11 have already been stopped.

This means that the voltage between the discharge lamp electrodes 4 and 6 at an instant between to and tl is the operating voltage B of the discharge lamp (approximately 100V
) is already equal to.

In the case of a discharge light (b) that is difficult to turn on, the starting operation is instantaneous.
1 and t2.

In the case of a discharge lamp (C) that does not light up, the voltage between the discharge lamp electrodes follows the supply voltage (220 V) after the instant t2.

At this time, the auxiliary transistor 30 remains conductive and no starting operation is performed.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a circuit of an embodiment of the device of the present invention together with a discharge lamp combined with this circuit, and Fig. 2 is a diagram showing the voltage peak between the electrodes of the discharge lamp of Fig. 1 as a function of time. It is. 1.2...terminal, 3...ballast, 4,
6... Preheating electrode, 5... Low pressure mercury vapor discharge lamp, 7.8.26.34... Capacitor,
9...Inductor, 10~13.32...
...Diode, 20,24.27...Resistance,
21.23...Transformer winding, 22...
NPN) transistor, 2g', 33...Zener diode, 28...bidirectional surrender element, 3
0...NPN type auxiliary transistor, 42...
...Spike suppressor.

Claims (1)

[Scope of utility model registration request] Device for starting and powering a gas and/or vapor discharge lamp 5 comprising two electrodes 4, 6 and having a frequency of 100
It comprises two input terminals 1, 2 for connection to an alternating current voltage source of less than Hz, these two input terminals 1, 2 being connected to at least a stabilizing inductor 3 during starting and powering the discharge lamp 5. and a discharge lamp 5, the two discharge lamp electrodes 4 and 6 are interconnected by a series circuit having a diode bridge 10 to
13, and the two output terminals of this diode bridge are interconnected by means of a starter with a first semiconductor switching element 22, in parallel to the branches 20, 21, 22 with this first semiconductor switching element 22. , providing control circuits 23 to 41 for the first semiconductor switching element 22,
This control circuit comprises at least a first capacitor 26 and at least an auxiliary transistor 30 of the starter which shunts the first capacitor 26,
a branch 28 connecting the control electrode of the first semiconductor switching element 22 to the main electrode of the first solid conductor switching element 22;
27.26, when the voltage between the terminals of the first capacitor 26 exceeds the threshold, the first semi-conducting switching element 2
2 is conductive, and the base of the auxiliary transistor 30 is connected to the control circuit, that is, to the connection point between the first resistor and the second capacitor 37, and the first resistor 31 and the second capacitor 37 are connected in series with each other. and parallel to the branches 20, 21, 22 with the first semiconductor switching element 22, the series circuit having at least the first resistor 31 and the second capacitor 37 is supplied with power by the diode bridges 10-13. In the discharge lamp starting and power supply device, the base of the auxiliary transistor 30 is connected to the connection point between the first resistor 31 and the second capacitor 37 through a Zener diode 33, and the two discharge lamp electrodes 4, 6 are connected to each other. are connected to each other by a third capacitor 8,
A second inductor 9 is provided in a connection circuit connecting the discharge lamp electrode 4.6 to the first semiconductor switching element 22, and when the first semiconductor switching element 22 is switched, the second inductor 9 is connected to the first semiconductor switching element 22. 3, together with the capacitor 8, provides a transient voltage between the discharge lamp electrodes 4, 6 which is higher than the supply voltage between the input terminals 1, 2, so that after a certain time a higher transient voltage is applied to the discharge lamp electrodes 4, 6. In other words, there is a delay in making the first semiconductor switching element 22 conductive, and this delay is caused by the charging of the second capacitor 37 that reaches the Zener voltage of the Zener diode 33. A discharge lamp starting and power supply device characterized by: