US3473085A - Device for controlling the voltage supply to an electric load - Google Patents

Device for controlling the voltage supply to an electric load Download PDF

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Publication number
US3473085A
US3473085A US637140A US63714067A US3473085A US 3473085 A US3473085 A US 3473085A US 637140 A US637140 A US 637140A US 63714067 A US63714067 A US 63714067A US 3473085 A US3473085 A US 3473085A
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United States
Prior art keywords
voltage
control
terminal
transformer
supply
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Expired - Lifetime
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US637140A
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English (en)
Inventor
Philippe Cailleux
Claude Mothiron
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US Philips Corp
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US Philips Corp
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current
    • G05F1/12—Regulating voltage or current wherein the variable actually regulated by the final control device is ac
    • G05F1/40—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices
    • G05F1/44—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only
    • G05F1/45—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only being controlled rectifiers in series with the load
    • G05F1/455—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only being controlled rectifiers in series with the load with phase control
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current
    • G05F1/12—Regulating voltage or current wherein the variable actually regulated by the final control device is ac
    • G05F1/40—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices
    • G05F1/44—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only
    • G05F1/445—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only being transistors in series with the load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/006—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output using discharge tubes
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/145—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
    • H02M7/15—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using discharge tubes only
    • H02M7/151—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using discharge tubes only with automatic control
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/30—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/30—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp
    • H05B41/34—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp to provide a sequence of flashes

Definitions

  • a pulse-type control voltage for adjust-ing the firing angle of the controlled rectifiers is produced in a control circuit comprising a transformer having a primary winding composed of two electrically interconnected windings having 'a common junction that is connected to one terminal ofthe A.C.
  • a pulse-type signal is generated in the secondary winding of the transformer that is further modified and applied to the gate electrodes of the controlled rectifiers to control the firing angle thereof.
  • the present invention relates to apparatus for controlling the ignition of gas discharge devices or the like, and more particularly to a device for adjusting the power supplied to a fluorescent lamp by means of controlled rectifiers.
  • the starting instant of the discharge during each half period is, in general, determined by means of -a controldevice comprising a thyratron or a thyristor.
  • the duration of the conduction of a thyristor or thyratron is controlled by a pulsatory auxiliary signal applied to an ignition electrodes or a control-electrode, the phase angles of said signal with respect to the supply voltage being controlled within suitable limits.
  • the known devices have the further disadvantage that the member for controlling the phase angle of the auxiliary signal, usually a potentiometer, exhibits a high voltage to ground so that special steps for insulation and safety are required, particularly in the case of remote control or automatic control by means of a photo-sensitive or thermo-sensitive member.
  • the present invention obviates these disadvantages.
  • the voltage applied to the control-circuit is obtained from the voltage differences between the voltages across each of the primary half windings, that is to say from the difference between the voltage of the alternating-voltage source and the voltage derived therefrom by the controlled rectifiers. Subsequent to rectification and smoothing of the voltage across the secondary winding of the transformer, it is thus possible to produce pseudo-trapezoidal pulses of double the supply frequency.
  • the pulse width is adjustable by controlling the duration of conduction of the controlled rectifiers.
  • controlled rectifiers denotes not only a gas-discharge thyratron but also a thyristor.
  • the device according to the invention is particularly suitable for the control of discharge lamps, it may, of course, also be employed for controlling the light flux of incandescent lamps, the power of electric heating systems or the speed of motors.
  • the device according to the invention is advantageous to connect between the neutral lead and one phase of the alternating supply voltage, the neutral lead being connected to the central point of the primary winding of the transformer.
  • FIG. 1 shows the basic diagram of a device according to the invention
  • FIGS. 2a, 2b and 2c illustrate the voltage waveforms at the terminals of the various windings of a transformer of a device shown in FIG. 1;
  • FIGS. 3a, 3b and 3c show the voltage waveforms across the control-circuit of the device shown in FIG. 1;
  • FIG. 4 shows the diagram of a practical embodiment of a device according to the invention.
  • FIG. 5 shows the diagram of a photo-sensitive member suitable for use in a device according to the invention for automatic control of an illumination system.
  • the device shown in FIG. 1 comprises a transformer TR having a primary winding divided into two centrally interconnected halves P and P
  • the free end of the primary half winding P is connected through a resistor R to the terminal 9 of one phase of the alternatingvoltage source.
  • the common central point is directly connected to the terminals 8 and 10 of the voltage source and the load, respectively.
  • Terminal 8 is connected to the neutral lead of the supply source.
  • the free end of the primary half winding P is connected through a resistor R to the controlled phase of the output voltage (terminal 12).
  • the secondary winding S of the transformer TR supplies the input voltage for a control-circuit 13.
  • the control circuit produces switching pulses which are transferred through the primary winding P of a transformer TR having two secondary windings S and S to a device 14 comprising controlled rectifiers.
  • FIG. 2a illustrates, as a function of time t, one period of the alternating supply voltage U at the terminals 8, 9 of the primary half winding P of the transformer TR
  • FIG. 2b illustrates the voltage U across the primary half winding P A portion of this voltage is cut oil? by the circuit 14, that is to say half of each half period.
  • FIG. 20 illustrates the voltage U at the terminals of winding S resulting from the application of the voltages of FIGS. 2a and 2b in phase opposition to the transformer TR It will be obvious that the voltage U may be cut off at a different point from that shown in the figures by shifting the starting instant of the conduction period of the controlled rectifier of the circuit 14. Thus the width of the pulses forming said voltage is varied.
  • FIG. 3a illustrates again the signal U of FIG. 20.
  • FIGS. 3b and 3c illustrate the signal U as a function of time t subsequent to rectification (U and smoothing (U The signal U is supplied to the circuit of variable time constant included in the control circuit 13.
  • controlcircuit 13 includes a bridge rectifier formed by the diodes D D D and D
  • the input of the circuit is connected to the secondary winding S of the transformer TR while the negative terminal is connected to the ground terminal 7.
  • a Zener diode Z is connected with its anode to the negative terminal and with its cathode to the positive terminal of said bridge.
  • the last-mentioned terminal is furthermore connected to the junction of a variable resistor R and a resistor R
  • the other end of the resistor R is connected to one of the bases of a double-base transistor T
  • the other end of the variable resistor R 4 is connected to the junction of the variable resistor R having a voltage-dependent resistance characteristic curve (VDR), and resistor R
  • VDR voltage-dependent resistance characteristic curve
  • resistor R The other end of resistor R is connected to the negative terminal of the bridge.
  • a resistor R is connected on the one hand to R and on the other hand to a terminal 4, which can be connected through a connecting member 6 to a terminal 5.
  • a diode D is connected with its anode to the terminal 5 and with its cathode to the emitter of the transistor T
  • a capacitor C is connected between the emitter of transistor T and the negative terminal of the rectifying bridge.
  • the second base of the transistor T is connected to said negative terminal through the primary winding P of the pulse transformer TR
  • the winding P is shunted by a diode D the anode of which is connected to the negative terminal.
  • the terminal 1 and 2 of the resistor R and the terminal 3 connected to said negative terminal via an adjustable resistor R may be connected to a potentiometer 15.
  • the ends of the potentiometer are connected to the terminals 1 and 3 and the tapping 16 is connected to the terminal 2.
  • the switching circuit 14 comprises the two thyristors TH and TH connected in parallel opposition between the terminals 9' and 12', which are connected to the terminals 9 and 12, respectively, through anti-interference inductors L and L which are magnetically coupled.
  • the input terminal of the secondary winding S of the transformer TR is connected to the terminal 12 and the input terminal of the secondary winding S is connected to the terminal 9'.
  • the other ends of S and S are connected to the control-electrodes of TH and TH respectively, through the resistors R and R
  • a circuit formed by the series combination of the resistor R and the capacitor C is connected in parallel with the thyristors TH and TH
  • a resistor R is connected between the output terminal 12 of the controlled phase and the neutral lead (terminals 8, 10).
  • the terminals 9' and 12 of the switching circuit 14 are connected through the resistors R and R respectively to the ends of the windings P and P of the transformer TR Between the terminals 8 and 9 a capacitor C is arranged.
  • the capacitors C and C are connected between the terminal 7 and the terminals 9 and 8.
  • a fluorescent lamp L is energized via the series apparatus 17, formed by an auto-transformer TR having secondary heating windings S and and a primary winding P and by an inductor L and a capacitor C
  • the common point 18 of windings S and P is connected to one of the terminals of the capacitor C the other terminal of which is connected to the junction of S and L
  • the point 18 and the free ends 19 and 20' of P and L respectively, are connected to the terminals 10, 11 and 12, respectively.
  • the device operates as follows. To one of the bases of the transistor T is connected the primary winding P of the pulse transformer TR The secondary windings S and S control the thyristors TH and TH When the potential of the charge on the capacitor C exceeds the threshold value of the transistor T the latter becomes conducting so that the discharge current of C passes through the winding P of the transformer TR As a result, a pulse is produced at the terminals of each of the secondary windings S and S and applied simultaneously to the control-electrodes of TH and TH via the equalizing resistors for the control-pulses R and R At this instant, only that thyristor whose cathode is negative and whose anode is positive becomes conducting.
  • FIGS. 2a and 2b illustrate the voltages across the windings P and P
  • FIG. 2c shows that the secondary winding S of TR, will supply voltage only in the absence of current through the primary half winding P which means, when the thyristors are cut ofl during each half period.
  • the diode D serves to cut ofl? the positive voltage peaks of small amplitude during the intervals when the supply voltage for the control-circuit is suppressed.
  • these voltages could be transferred to the connecting conductors of P and may produce a premature ignition of the double-base transistor.
  • the diode D serves to suppress the negative voltage peaks across the winding P due to the reaction of the voltages in the primary winding, produced at the extinction of the thyristors, alternately at the terminals of the two secondary windings. These voltages, by raising the voltage between the two bases of the transistor, might otherwise alter the operational conditions thereof.
  • the connecting portion 6 can be removed and a photosensitive element can be inserted in the charging circuit of C
  • the effective or equivalent resistance of said element increases or decreases as a function of the incident light flux in accordance with the desired efiect.
  • the device shown in FIG. 5 may be arranged between the terminals 4 and 5.
  • stabilisation or adaptation of the heating may be achieved by using a resistor having a positive or negative temperature coefiicient, to which, if necessary, a transistor can be connected.
  • PTC positive temperature coelficient
  • NTC negative temperature coefiicient
  • a PTC resistor may be connected in series between the terminals 4 and 5 in the heated room and an NTC resistor may be arranged outside, so that the two control methods are combined.
  • the circuit of variable time constant includes an adjustable resistor R A further adjustable resistor R accessible from the outside, permits the technician to adjust the minimum light flux for each particular use.
  • the two inductors L and L wound in opposite senses on a ferrite core suppress the transient volt-age peaks appearing in some supply lines that otherwise cause arbitrary fluctuations of the light flux when the device is used for controlling fluorescent lamps.
  • These inductors form, in addition, an effective protection against the propagation of radio disturbance through the conductors of the supply.
  • the resistor R suppresses current fluctuations that would occur upon the extinction of one of the lamps due' to the unavoidable tolerances of the characteristics of the fluorescent lamps.
  • the capacitors C and C between each of the conductors of the supply and ground and the capacitor C between the terminals of the supply serve to prevent the propagation of radio disturbances, produced by the switching effect of the device, along the conductors of the mains.
  • the lamp L is fed via a ballast 17.
  • This ballast is formed by the auto-transformer TR having a winding P connected to the supply and the windings S and S for heating the electrodes of the lamp L.
  • One of the supply conductors includes an inductor L A capacitor C improves the power factor of the ballast.
  • ballast TR is an auto-transformer and the conductor 19 is connected to the conductor 20.
  • the conductor 18 is connected to the terminal 10 and the conductor 19 to the terminal 11 so that the filament wires of the lamp L can be energized in a normal manner.
  • the supply conductor 20 of the inductor L of the series apparatus is connected to the terminal 12, that is to say the controlled terminal of the device according to the invention.
  • This photo-sensitive member comprises a transistor 26 of the pnp-type, the emitter of which is connected to the terminal 25 and the collector to the terminal 24.
  • the potential of the base with respect to the emitter is derived from the voltage between the emitter and the collector by means of the photosensitive resistor 28, which forms a voltage divider with the adjustable resistor 27.
  • the base of the transistor 26 is connected to the junction of the resistor 27 and 28.
  • the photo-sensitive resistor 28 which is preferably formed by a cadmium sulphide cell, may be shunted by an adjustable resistor 29 in order to obtain a suitable working point for the device.
  • the adjustable resistor 27 contributes to the setting of the working point of the arrangement and its sensitivity.
  • Such a photo-sensitive member with amplification does not require a separate voltage source and is supplied automatically by the charging current of the capacitor C of FIG. 4.
  • the ohmic resistance value is low so that the base and collector currents of the transistor 26 also are low.
  • the equivalent resistance of the transistor 26 is then high.
  • the equivalent resistance value of the photo-sensitive member is low so that a control member is obtained which automatically aifects the operation of the device of FIG. 4 to maintain an illumination of substantially constant level.
  • the illumination has to be matched to the level of a variable illumination, it is sufiicient to invert the positions of the resistors 27 and 28 in the arrangement.
  • resistor 29 then remains connected in parallel with the photosensitive resistor 28.
  • a device for controlling the power supplied to a load from an alternating current source said device including controlled rectifier means and an associated control circuit for producing phase adjustable pulse type control voltages for the control electrodes of the controlled rectifier means, said device comprising first and second input terminals and first and second output terminals, a transformer having a primary winding and a secondary winding, said primary winding having first and second interconnected windings, means connecting the junction of the first and second windings to the first input terminal and the first output terminal, means connecting the other end of the first winding to the second input terminal and the other end of the second winding to the second output terminal, means connecting said controlled rectifier means between the said other ends of the first and second windings, and means connecting said control circuit to the secondary winding of the transformer, whereby said control circuit provides control pulses to render said controlled rectifier means conductive.
  • a device as claimed in claim 1 wherein the load comprises at least one discharge lamp and the controlled rectifier means comprises first and second controlled rectifiers connected in anti-parallel configuration.
  • a device as claimed in claim 1 wherein said input terminals are connected to said AC source and said first and second windings are wound in phase opposition to produce flux cancellation in the transformer whereby voltage pulses are produced in said secondary winding only during the time intervals that the controlled rectifier means are cut-off.
  • control circuit comprises, a trigger device having its output coupled to the control electrodes of said controlled rectifier means, an RC network coupled to the input of said trigger device to control the operation thereof, means coupling said secondary winding to the input of said RC network, and means for adjusting the RC time constant of said RC network thereby to control the point of conduction of said trigger device and the firing angle of said controlled rectifier means relative to said AC source.
  • said RC network includes a photosensitive element connected in series with the timing capacitor of said RC network and responsive to incident light energy so as to vary the time constant of said RC network as a function thereof.
  • said controlled rectifier means comprises first and second controlled rectifiers connected in anti-parallel and said first and second windings are wound in phase opposition to produce flux cancellation in the transformer whereby voltage pulses are produced in said secondary winding only during the time intervals that the controlled rectifier means are cut-off, said device further comprising a resistor and capacitor serially connected in shunt with said first and second controlled rectifiers.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Circuit Arrangement For Electric Light Sources In General (AREA)
US637140A 1966-05-11 1967-05-09 Device for controlling the voltage supply to an electric load Expired - Lifetime US3473085A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR61167A FR1507165A (fr) 1966-05-11 1966-05-11 Dispositif permettant de régler l'alimentation d'une charge électrique

Publications (1)

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US3473085A true US3473085A (en) 1969-10-14

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US637140A Expired - Lifetime US3473085A (en) 1966-05-11 1967-05-09 Device for controlling the voltage supply to an electric load

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US (1) US3473085A (no)
JP (1) JPS4624228B1 (no)
BE (1) BE698232A (no)
DE (1) DE1638493A1 (no)
FR (1) FR1507165A (no)
GB (1) GB1180755A (no)
NL (1) NL6706438A (no)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3358186A (en) * 1962-12-30 1967-12-12 Tokyo Shibaura Electric Co Dimmer for electric lamps

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3358186A (en) * 1962-12-30 1967-12-12 Tokyo Shibaura Electric Co Dimmer for electric lamps

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Publication number Publication date
NL6706438A (no) 1967-11-13
BE698232A (no) 1967-11-09
DE1638493A1 (de) 1970-10-22
FR1507165A (fr) 1967-12-29
GB1180755A (en) 1970-02-11
JPS4624228B1 (no) 1971-07-12

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