JPH05290984A - Electronic starter - Google Patents

Abstract

PURPOSE:To shorten time required for lighting by making the function of a glow lamp solid state. CONSTITUTION:The length of preheating time is primarily determined by a thermistor R1 and a capacitor C2. As the current added to terminals X and Y is higher, so is the current charged to C1 through D1 as well as the current charged to C2 through a diode D3 and R1 increased. The velocity of rise in the voltage of C2 becomes faster, and so the time becomes faster for turning a transistor Q1 on. When Q1 is turned on, Q2 is turned on while an FET Q3 is turned off and preheating is thus finished. The time of preheating is shortened when the voltage is considered to be high, or when the amount of preheating current is considered to be large, while elongating the preheating time when the voltage is low, and an optimum preheating time span is provided. While a bimetal part is heated and contacts are closed to make preheating current flow in the case of glow discharging, an FFETQ3 of this electron starter is turned on immediately if a lamp is not yet lighted, and preheating is started. The time required can thus be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to lighting fluorescent lamps.

[0002]

Glow lamps are mainly used.

[0003]

Generally, the glow lamp used has a long life, but it is a consumable item and the performance is inevitably lowered. It takes some time to start the fluorescent lamp, but it also includes the time until the contact point of the glow lamp is closed. The timing at which the contacts of the glow lamp separate is unrelated to the energy stored in the ballast, and therefore may fail to start.

[0004]

[Means for Solving the Problem] The solution of the glow lamp was solved by making the function of the solid state.

[0005]

With respect to claim 1, the glow lamp has a state when the contact is closed and a state where it is opened. If the contact is turned into a solid state as it is, the circuit power of the electronic starter can be obtained when the contact is closed. become unable. Therefore, the circuit power supply is obtained by the positive (or negative) half-wave of the alternating current, and the preheating current is obtained by the negative (or positive) half-wave. In FIG. 1, when a positive voltage is applied to X and a negative voltage is applied to Y, the current supplies the power to the winding A through the diode D ₁ . Conversely, when a negative voltage is applied to X and a positive voltage is applied to Y, the preheat current flows through FET Q ₃ (if closed) and diode D ₂ . Therefore, the power source of the circuit can be obtained even during the preheating.

With respect to claim 2, the noise-preventing capacitor is connected in parallel with the electronic starter, but there are times when a high-voltage starting voltage is stored in this capacitor. If FETQ ₃ turns on at that time, FE
There are times when you will be overwhelmed by exceeding the rated current of T. Therefore, as shown in FIG. 1, a resistor R ₇ and other current limiting element in series are inserted in the circuit to protect the FET Q ₃ .

Regarding claim 3, the preheating time is mainly determined by the thermistor R ₁ and the condenser C _{2 although} the details of FIG. 2 will be described later. The higher the voltage applied to X and Y, the greater the current charged to C ₁ through D ₁ and the current charged to C ₂ through D ₃ R ₁ . Therefore, the voltage rising speed of C ₂ becomes faster and the transistor Q ₁ is turned on faster. When Q ₁ turns on, Q ₂ turns on and FET Q ₃ turns off, ending preheating. In this way, the preheating time is shortened when the voltage is high, that is, when the preheating current is considered to be large, and conversely, when the voltage is low, the preheating time is lengthened to obtain the optimum preheating time.

Regarding Claim 4, it is preferable to determine the optimum preheating time by slightly changing the filament preheating time according to the ambient temperature. This is because preheating takes a little longer at low temperatures. In FIG. 2, the temperature sensing element thermistor R ₁ is used to change the preheating time depending on the ambient temperature. An ordinary thermistor is an element in which the resistance value decreases as the temperature rises and the resistance value increases as the temperature lowers. When the temperature rises, the resistance value of the thermistor R ₁ decreases and the current flowing through the capacitor C ₂ increases, so that the voltage rising speed of the capacitor C ₂ becomes faster and the time for turning on the transistor Q ₁ becomes faster. When Q ₁ turns on, transistor Q ₂
Also turns on and the FET Q ₃ turns off and preheating ends.
This reduces the preheat time.

About Claim 5 The energy generated in the ballast at the time of starting is very large,
When the fluorescent tube is damaged, this energy loses its place and FE
There is a case of exceeding the avalanche tolerance of T and giving a crush. When this happens, the FET is turned on for protection. When a very high positive voltage is applied to Y in FIG. ₂ , a voltage is applied to the gate of the FET Q ₃ through the diode D ₄ and the Zener diode Z ₂ . Thereby FE
TQ ₃ turns on and absorbs this energy. FETQ ₃ was protected by that.

Regarding Claim 6 In the present circuit, the preheating current is obtained by the positive (or negative) half wave and the power source of the circuit is obtained by the negative (or positive) half wave. Therefore, there is a possibility that the FET Q ₃ may be cut off during a negative (or positive) half-wave in which the preheating current does not flow. At that time, the ballast does not generate the starting voltage and cannot be lit. Therefore, the positive (or negative) voltage through which the preheating current flows is detected to detect the FET Q ₃
To shut off. In FIG. _{2, even if} the voltage of the capacitor C ₂ reaches a certain level or higher, if the positive voltage is applied to X and the negative voltage is applied to Y, the transistor Q ₁ cannot be turned on. That is, the base current cannot be supplied.
The base current of the transistor Q ₁ can flow through the Zener diode FZ ₁ only when a negative voltage is applied to X and a positive voltage is applied to Y and the voltage of the capacitor C ₂ reaches a certain level or more. When Q ₁ turns on, Q ₂ also turns on and FET Q ₃ shuts off. In this way, the starting voltage was obtained by interrupting the current only when the preheating current was flowing.

With respect to claim 7, when a reverse current is applied to the FET, the FET may occasionally fail. The diode D ₄ FE as shown in FIG. 2 for the
It is put in series with T so that reverse current does not flow, and diode D
₁ , D _{2, the} resistor R ₇ , and the Zener diode Z ₃ are arranged such that the positive current half wave and the negative current half wave are separated from each other. When a positive voltage is applied to X, it flows to Y through the diode D ₁ , the capacitor C ₁ , the resistor R ₆ Zener diode Z ₃ , and the resistor ₇ . The voltage stored in the capacitor C ₁ serves as the circuit power supply. When the voltage is applied to Y this time, it flows to X through the diode D ₄ , the FET Q ₃ and the diode D ₂ during the preheating. In this way, the device is devised so that the reverse current does not flow in the FET and the current path is separated into positive and negative half waves.

With respect to claim 8, in the present circuit, even if the lighting fails, the lighting is performed again after a while. When the fluorescent lamp reaches the end of its life, it is repeatedly heated and stopped (no current flows). The gate voltage waveform of the FET is shown in FIG. 3 (C). It becomes preheated during the period of T ₁ and pauses at T ₂ . In other words, the averaged current value is low, and even if the fluorescent lamp reaches the end of its life, no burden or great heat is generated on the ballast, the fluorescent tube and the electronic starter. This has the merit that the safety can be secured independently unless the parts of the electronic starter are broken. Actually, even if the parts of the electronic starter are broken, it is undeniable that temperature fuses and other parts will finally secure the safety, but it is a method that does not depend on such parts, so high safety Can be demonstrated.

Description of Circuit (FIG. 2) When a positive voltage is applied to X, the capacitor C ₁ is immediately charged by passing through the diode D ₁ and the resistor R ₆ Zener diode Z.
Current flows through ₃ and the resistor R ₇ . The voltage of C ₁ becomes the power source of the circuit, and a voltage is applied to the gate of the FET Q ₃ through the resistor R _4, which causes the FET Q ₃ to immediately become conductive. Further, the electric charge of the capacitor C ₁ gradually flows to the capacitor C ₂ through the diode D ₃ and the thermistor R _1, and the voltage of the capacitor C ₂ gradually rises. When a positive voltage is applied to Y, it flows to X through the resistor R ₇ , the diode D ₄ , the FET Q ₃ , and the diode D ₂ . This current becomes the preheating current. When this operation is repeated for about 0.5 seconds, the voltage across the capacitor C ₂ rises to the extent that it can pass through the Zener diode Z ₁ .
At that time, if a positive voltage is applied to Y, the base current of the transistor Q ₁ passes through the Zener diode Z ₁ and becomes X.
Flows to. Then, the transistor Q ₁ is turned on and the base current of the transistor Q ₂ flows through the resistor R ₂ . As a result, the transistor Q ₂ also turns on and the FET
The gate voltage of Q ₃ becomes the same level as the cathode and FET Q
₃ is cut off. When Q ₃ is cut off preheating current is cut off the fluorescent tube starting voltage to the ballast is generated to start lighting. The charge of the capacitor C ₂ is the transistor Q ₂ and the resistance R.
It flows to the base of the transistor Q ₂ through the _2, continue to turn on the transistor Q _2. After that, the voltage of the capacitor C ₂ gradually decreases, and after about 1 second, the transistor Q ₂ turns off. At this time, the electric charge of the capacitor C ₁ also disappears through the resistor R ₄ , so the FET Q ₃ is not turned on. If it is lit here, the voltage applied to X and Y drops, and the Zener diode Z ₃ cannot pass. As a result, the circuit power cannot be obtained and the FET Q ₃ cannot be turned on. If the lighting has failed, the circuit power is obtained through the Zener diode Z _3, and the re-preheating is started. At the end of the life of the fluorescent tube, such operations are repeated.

[0014]

As described above, according to the present invention, in the glow lamp, the bimetal portion generates heat due to the glow discharge, and the preheating current flows only when the contacts are closed, whereas the electronic starter requires such time. If it is not turned on at all, the FET Q ₃ is turned on immediately to start preheating as described above. As a result, the time it takes to close the glow lamp contacts is reduced with this electronic starter. In addition, in the claw lamp, there is variation in the time from when the contacts are closed to when they are separated, and there is a case where sufficient preheating is not obtained and preheating is repeated many times. On the other hand, this electronic starter shortened the time required for lighting by giving an optimum preheating time.

[Brief description of drawings]

FIG. 1 shows a block diagram of this circuit. A ... Control circuit D ₁ . D ₂ ... Diode Q ₃ ... F
ET

FIG. 2 is a circuit diagram of the present invention. C ₁ . C ₂ . … Condenser D ₁ . D ₂ . D _3. D ₄ ... Diode Q ₁ . Q 2 _... transistor Q _{3 ...} FET R 1 ... thermistor R ₂ to R 7 _... resistance Z _1. Z ₂ . Z ₃ ... Zener diode

FIG. 3 is a time chart showing the voltage of each part. a ... voltage across b ... gate voltage T 1 _... preheating period T 2 _... rest period voltage across c ... _{Q 3} of _{C 2} of _{C 1}

[Figure 4] Circuit of actual fluorescent lamp L ... Choke

FIG. 5 is an external view of the present invention, which is compatible with a glow lamp.

Claims (8)

[Claims] 1. In an electronic starter using a semiconductor, a preheating current is obtained with a positive (or negative) half wave of an AC voltage applied to the circuit, and a power source of the electronic starter circuit is obtained with a negative (or positive) half wave. Made electronic starter. 2. The electric energy stored in the noise prevention capacitor sometimes destroys semiconductors such as FETs.
Therefore, an electronic starter that protects semiconductors such as FETs by inserting resistors and other current limiting elements in series with semiconductors such as FETs. 3. An electronic starter in which the filament preheating time is inversely proportional to the power supply voltage, and when the voltage is high (the preheating current is large), the preheating time is lengthened to ensure the preheating. 4. An electron for ensuring that the filament preheating time is inversely proportional to the ambient temperature and the preheating time is shortened when the ambient temperature is high and the preheating time is lengthened when the ambient temperature is low so that the preheating can be surely obtained. starter. 5. When the fluorescent tube is broken, the filament is eventually burned out, but until then, the energy generated in the ballast sometimes exceeds the avalanche resistance of the FET.
Therefore, when a voltage higher than the breakdown voltage of the FET is applied, a gate voltage is applied so that this energy is effectively absorbed by the FET to prevent the FET from being destroyed. 6. The preheating current flows in a positive (or negative) half-wave in this circuit. Therefore, there are times when the preheating current does not flow. Even if the FET is cut off when the preheating current is not flowing, the starting voltage is not generated in the ballast. Therefore, when the timing is detected and the preheating current is flowing, the FET
An electronic starter that shuts off the power to ensure that the starting voltage is obtained. 7. The FET may be rarely destroyed when a reverse current is applied to the FET. Therefore, the electronic starter is designed to obtain the power supply of the electronic starter circuit without flowing the reverse current to the FET. 8. An electronic starter that does not require a protective device unless the parts and the like have abnormalities by repeating preheating and rest during the life of the fluorescent tube.