CN2148456Y

CN2148456Y - Lamp failure protector for electronic ballast of single or multiple lamps

Info

Publication number: CN2148456Y
Application number: CN 93200926
Authority: CN
Inventors: 武斐
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-01-01
Filing date: 1993-01-01
Publication date: 1993-12-01
Anticipated expiration: 2003-01-01

Abstract

The utility model relates to a lamp failure protector for electronic ballast of single or multiple lamps. The protector fetches pressure and sampling from an LCR circuit choking inductance. When the circuit is in electric flux but keeps high frequency over current action because of lamp failures, the protector forces the circuit to reduce vibration and limit current and prevents the circuit and the components of a main circuit from the damages of high frequency over current for a long time. The utility model realizes the current limiting protection of the lamp failure circuits of single or multiple lamps, permits normal light circuits to continually work, ensures base light on site and carries out complete current limiting protection to all lamp failure circuits. The protector is more suitable for electronic ballasts of multiple lamps with medium and large powers and paves a flat path for gas electric discharge of group lamps.

Description

Lamp failure protector for electronic ballast of single or multiple lamps

The utility model is a kind of particularly single, multi-lamp electric ballast lamp failure protective device of fluorescent lamp of gaseous discharge lamp that is applicable to.

Compare with inductance type ballast, electric ballast has efficient electricity-saving, no buzzer, advantages such as no stroboscopic sense and anti-low voltage starting.A machine electronic ballast for multiple lamps particularly, more apparent its advantage with low cost has much promotional value.But having one to N(N usually is natural number, its higher limit by power switch component such as switching transistor, controllable silicon portative lamp number determine) the single, multi-lamp electric ballast of individual LCR oscillating circuit (hereinafter to be referred as the LCR circuit) remains flimsy deficiency under abnormality.Especially when lamp failure occurring, then this lamp place LCR circuit often continues the high frequency overcurrent when electricity is logical, cause this circuit and major loop (refer to each LCR circuit single, multi-lamp electric ballast comparatively speaking in other functional circuits, down with) in the element thermal breakdown.

Task of the present utility model is; for common; element that each LCR circuit himself comprises under the prerequisite with main oscillations electric capacity and choke induction and connection and can have various feasible schemes and not Procrustean single, multi-lamp electric ballast that a kind of lamp failure protective device is provided with the connection of other circuit; when the LCR circuit electricity that adds this protective device logical but when continuing the high frequency overcurrent because of lamp failure; force this circuit vibration damping current limliting; thereby the electric current of major loop is limited in the safe range, and the element in protection place LCR circuit and the major loop exempts from that the high frequency overcurrent damages when long.

Of the present utility model being characterised in that: the lamp failure protective device is used for being installed at the LCR circuit of single, multi-lamp electric ballast, and protective device has a pressure loop, a voltage divider, a time-delay trigger network and a gate-controlled switch.The pressure loop is from the preferably pressure on the choke induction of place LCR circuit inductance element; voltage divider dividing potential drop from the pressure output voltage loop is sampled and the delay capacitor the time-delay trigger network is charged; when protective device place LCR circuit electricity logical but when continuing the high frequency overcurrent because of lamp failure; voltage on the delay capacitor just provides a triggering signal to make the gate-controlled switch action; with big electric capacity; small resistor is incorporated the LCR circuit into forces this circuit vibration damping current limliting; perhaps will comprise main oscillations electric capacity at least on the LCR circuit of place and do not comprise any circuit section short circuit of choke induction; make this circuit vibration damping current limliting; the shared element of a plurality of LCR circuit between the node of a plurality of LCR circuit and the major loop is (except the choke induction; as belong to self-maintained circuit; except the pulse transformer), can together be fallen by weak point.

Below, concrete feature of the present utility model and embodiment are described in conjunction with the accompanying drawings.

Be single, multi-lamp electric ballast lamp failure protective device 6 of the present utility model in the chain-dotted line frame 6 in the accompanying drawing 1, surplus is a part with protective device 6 closely-related place LCR circuit.LCR circuit in the accompanying drawing 1 is under the prerequisite with main oscillations capacitor C and choke induction L, and the element that himself comprises can have various feasible schemes and not impose consistent with connection and with the connection of other circuit.Inferior oscillating capacitance C ' and filament R ₅, R ₆Shunt capacitance C _R, C _RAll not essential.Being pressure loop 1 in the dot-dash wire frame 1 in the accompanying drawing 1, is voltage divider 2 in the frame 2, for time-delay trigger network 3, is gate-controlled switch 4 in the frame 4 in the frame 3, and pressure loop 1 has pressure coil L ₁, building-out capacitor C ₁, rectification link X and filtering keeps capacitor C ₂L ₁Directly add around place LCR circuit inductance element preferably on the iron core of L or the skeleton to obtain induced voltage U _L, L ₁Same C ₁The series connection back is connected with the input side of X.U _LThrough C ₁After adjustment, the X rectification, export a direct current voltage U at the outlet side of X ₁, U ₁Anodal H be connected C respectively with negative pole K ₂Positive pole and negative pole, C ₂Having filtering and voltage concurrently persists to guarantee the function of follow-up gate-controlled switch 4 reliable trigger actions.C ₁, C ₂Can save C respectively or together ₁When saving with its shorted on both ends.Voltage divider 2 is by divider resistance R ₁, R ₂Be in series, its two ends connect H point and K point respectively.Following divider resistance R ₂On dividing potential drop U ₂Be sampled voltage and to the delay capacitor C of time-delay in the trigger network 3 ₃Charging.Time-delay trigger network 3 has resistance R ₃With delay capacitor C ₃, its charging current flows into the dividing point M that end connects voltage divider 2, and outflow end connects K point, C ₃But series and parallel Resistor-Capacitor Unit or parallel voltage-stabilizing element, R ₃Can save simultaneously with its shorted on both ends.C ₃The trigger control end G of anodal F and follow-up gate-controlled switch 4 between can be connected threshold switch element such as diac, diode, voltage-stabiliser tube and resistance.Time-delay trigger network 3 is used for the charging time-delay and provides triggering signal to gate-controlled switch 4 when lamp failure causes place LCR circuit to continue the high frequency overcurrent.Gate-controlled switch 4 both can be a contact switch, can also be noncontacting switch.Gate-controlled switch 4 be contact switch situation as shown in Figure 2.This moment, gate-controlled switch 4 had a drive circuit 5 and a contact S.Drive circuit 5 is by current-limiting resistance R ₄, electromagnetic relay J excitation coil J _SBe in series arbitrarily with the positive negative electrode of unidirectional controllable silicon S CR, its drive current flows into end H ' connection H point, outflow end K ' connection K point, R ₄Can save simultaneously with its shorted on both ends.The control utmost point G of SCR as the trigger control end of gate-controlled switch 4 directly or through behind threshold switch or the resistive element with C ₃Anodal F link to each other.Resistance be can be connected between G and the K, element or clamp element held.J _SBe parallel with diode D in order to afterflow.Contact S is make contact (normally opened contact) both, can also be transfer contact, can also be to close bridging contact or change bridging contact, the accompanying drawing 2 a kind of situation wherein of only having drawn.At least comprise C but the two ends that do not comprise any circuit section of L are connected behind direct or limited element of series and parallel of two ends W, the W of S contact such as Resistor-Capacitor Unit, the rectifier cell with on the LCR circuit of place, the shared element of a plurality of LCR circuit between the node of a plurality of LCR circuit and the major loop is (except the choke induction, as belong to self-maintained circuit, except the pulse transformer), can be included within the circuit section that two ends, S contact W, W defined.Only a kind of in the many connectivity scenarios in S contact shown in the accompanying drawing 1.Gate-controlled switch 4 be noncontacting switch situation as shown in Figure 3.This moment, gate-controlled switch 4 had one drive circuit 5 ' and output port S '.5 ' by the positive and negative end P of the input side of solid-state relay J ', Q, current-limiting resistance R ' ₄, unidirectional controllable silicon S CR positive negative electrode be in series arbitrarily, 5 ' drive current flow into end H ' connection H point, outflow end K ' connection K point, but from P to Q diode of reverse parallel connection, the control utmost point G of SCR is directly or through connecting the F point behind threshold switch or the resistive element.Resistance be can be connected between G and the K, element or clamp element held.The connection of two terminal W, the W of S ' with contact gate-controlled switch 4 is arranged in the connection of two ends W, W of contact S identical.Similarly, shown in the accompanying drawing 1 only be a kind of in the many connectivity scenarios of S ' port.Each resistance in the protective device 6 can be or can the series and parallel fixed resistance, adjustable resistance, thermistor.

The utility model should be adjusted the sampled voltage U on 2 times divider resistances of voltage divider in force ₂, make U when the lamp operate as normal ₂Triggering level U less than SCR _GK, and when lamp failure causes place LCR circuit to continue the high frequency overcurrent, U ₂Greater than U _GKLike this, when the logical protective device 6 place LCR circuit lamps of electricity normally start, though U ₂Greater than U _GK, but because the time-lag action of time-delay trigger network 3, at C ₃On voltage U ₃Reach U _GKBefore, lamp is just lighted, U ₁Rapid drawdown, U ₂Go down after a rise to being lower than U _GKNumerical value, SCR does not trigger, gate-controlled switch 4 is failure to actuate, LCR circuit operate as normal.If place LCR circuit is owing to the high frequency overcurrent appears continuing in lamp failure, then the dl/dt of this circuit is high, L ₁Thereby the output voltage U in induced voltage pressure loop 1 ₁And then 2 times divider resistance R of voltage divider ₂On sampled voltage U ₂The triggering level U that always is higher than SCR _GK, through one section harmless time-delay, U ₃Reach U _GK, SCR triggering and conducting, J _SMust be electric, S is moving to be closed or changes; Perhaps the input side of J ' is opened the injection drive current from P to Q, and the pressure drop between S ' conducting and its two ends is zero volt or approaching zero volt, thereby will intend the excision of short-circuit section, perhaps incorporates limited Resistor-Capacitor Unit into place LCR circuit.Place LCR circuit is fallen by weak point because of original electric capacity of offsetting most of induction reactance or makes induction reactance outstanding because of having incorporated big electric capacity or small resistor into, and frequency reduces, and it is big that impedance becomes, and electric current reduces, and then the electric current of major loop is limited in the safe range.For multiple lamp electronic ballast, this moment, other LCR circuit worked on.If all N LCR circuit is all owing to lamp failure causes continuing the high frequency overcurrent and adding protective device 6 respectively, all as be subjected to current-limiting protection above-mentionedly, electric ballast is in full current-limiting protection state to then all LCR circuit.Both safe and reliable, convenient and practical again.

Claims

1; a kind of particularly single, multi-lamp electric ballast lamp failure protective device 6 of fluorescent lamp of gaseous discharge lamp that is applicable to; protective device 6 is used to be installed at the LCR oscillating circuit (hereinafter to be referred as the LCR circuit) of single, multi-lamp electric ballast; the element that the LCR circuit himself comprises under the prerequisite with main oscillations capacitor C and choke induction L can have various feasible schemes and not impose consistent with connection and with the connection of other circuit; it is characterized in that: lamp failure protective device 6 has a pressure loop 1; a voltage divider 2; a time-delay trigger network 3 and a gate-controlled switch 4; pressure loop 1 is from the preferably upward pressure of choke induction L of place LCR circuit inductance element; voltage divider 2 dividing potential drop from the output voltage in pressure loop 1 is sampled and the delay capacitor the time-delay trigger network 3 is charged; voltage on the delay capacitor is logical but trigger gate-controlled switch 4 when continuing the high frequency overcurrent because of lamp failure at LCR circuit electricity; behind gate-controlled switch 4 trigger actions with big electric capacity; small resistor is incorporated place LCR circuit into forces this circuit vibration damping current limliting; the any circuit section short circuit that perhaps will comprise C at least on the LCR circuit of place and do not comprise L forces place LCR circuit vibration damping current limliting; the shared element of a plurality of LCR circuit between the node of a plurality of LCR circuit and the major loop is (except the choke induction; as belong to self-maintained circuit, and except the pulse transformer) can together lack.

2, according to the lamp failure protective device 6 of claim 1, it is characterized in that: described pressure loop 1 has pressure coil L ₁, building-out capacitor C ₁, rectification link X and filtering keeps capacitor C ₂, L ₁Directly add inductance element in the LCR circuit of place preferably on the iron core or skeleton of choke induction L, L ₁Same C ₁Series connection back links to each other with the input side of X, the output voltage positive pole H of X and negative pole K respectively with C ₂Positive and negative electrode connect C ₁, C ₂Can save C respectively or together ₁When saving with its shorted on both ends.

3, according to the lamp failure protective device 6 of claim 1, it is characterized in that: described voltage divider 2 is by resistance R ₁, R ₂Serial connection forms, and its two ends are connected with negative terminal K with rectification link X output plus terminal H respectively.

4, according to the lamp failure protective device 6 of claim 1, it is characterized in that: described time-delay trigger network 3 has resistance R ₃With delay capacitor C ₃, its charging current flows into the dividing point M that end connects voltage divider 2, and outflow end connects rectification link X output negative terminal K, R ₃Can economize simultaneously with its shorted on both ends, C ₃The trigger control end G of anodal F and follow-up gate-controlled switch 4 between can be connected threshold switch element and resistance.

5, according to the lamp failure protective device 6 of claim 1, it is characterized in that: described gate-controlled switch 4 is contact switch, has a drive circuit 5 and a contact S, and drive circuit 5 is by current-limiting resistance R ₄, electromagnetic relay J excitation coil J _SForm with any serial connection of the positive negative electrode of unidirectional controllable silicon S CR, its drive current flows into the output voltage U of end H ' connection rectification link X ₁Anodal H, outflow end K ' connection U ₁Negative pole K, R ₄Can economize simultaneously its shorted on both ends, the control utmost point G of SCR directly or through behind threshold switch or the resistive element with delay capacitor C ₃Anodal F link to each other, can be connected resistance, appearance element or clamp element, J between G and the K _SBe parallel with sustained diode, S both can be a make contact, can also be transfer contact, can also be to close bridging contact or conversion bridging contact, the two ends W of contact, direct or the string of W, at least comprise the main oscillations capacitor C and the two ends that do not comprise any circuit section of choke induction L are connected behind limited the element in parallel with on the LCR circuit of place, the shared element of a plurality of LCR circuit between the node of a plurality of LCR circuit and the major loop is (except the choke induction, as belong to self-maintained circuit, except the pulse transformer), can be included in the two ends W of S, within the circuit section that W defined.

6, according to the lamp failure protective device 6 of claim 1, it is characterized in that: described gate-controlled switch 4 is noncontacting switch, has one drive circuit 5 ' and output port S ', 5 ' by the positive and negative end P of the input of solid-state relay J ', Q, current-limiting resistance R ' ₄Be in series arbitrarily with the positive negative electrode of unidirectional controllable silicon S CR, 5 ' drive current flow into end H ' connection rectification link X output voltage U ₁Anodal H, outflow end K ' connection U ₁Negative pole K, but from P to Q diode of reverse parallel connection, the control utmost point G of SCR is directly or through threshold switch or resistive element and delay capacitor C ₃Anodal F link to each other, can be connected Resistor-Capacitor Unit or clamp element between G and the K, at least comprise the main oscillations capacitor C and the two ends that do not contain any circuit section of main oscillations inductance L are connected behind direct or limited the element of connection in series-parallel of two ends W, the W of S ' with on the LCR circuit of place, the shared element of a plurality of LCR circuit is (except the choke induction between a plurality of LCR circuit node and major loop, as belong to self-maintained circuit, except the pulse transformer), can be included within the circuit section that S ' two ends W, W defined.

7, according to the gate-controlled switch 4 of time-delay trigger network 3, claim 5 and the claim 6 of the voltage divider 2 of the pressure loop 1 of the lamp failure protective device 6 of claim 1, claim 2, claim 3, claim 4, it is characterized in that: described each resistance can be or can the series and parallel fixed resistance, adjustable resistance, thermistor.