GB2157859A - A series switching regulator for power supplies - Google Patents
A series switching regulator for power supplies Download PDFInfo
- Publication number
- GB2157859A GB2157859A GB08508138A GB8508138A GB2157859A GB 2157859 A GB2157859 A GB 2157859A GB 08508138 A GB08508138 A GB 08508138A GB 8508138 A GB8508138 A GB 8508138A GB 2157859 A GB2157859 A GB 2157859A
- Authority
- GB
- United Kingdom
- Prior art keywords
- input voltage
- thyristor
- switching regulator
- voltage
- series switching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000001105 regulatory effect Effects 0.000 claims abstract description 12
- 239000003990 capacitor Substances 0.000 claims description 17
- 230000000295 complement effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
Classifications
-
- 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
- H02M7/155—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 semiconductor devices only
-
- 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
- H02M7/06—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
- H02M7/066—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode particular circuits having a special characteristic
-
- 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
- H02M7/21—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 triode or transistor type requiring continuous application of a control signal
- H02M7/217—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 triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/2176—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 triode or transistor type requiring continuous application of a control signal using semiconductor devices only comprising a passive stage to generate a rectified sinusoidal voltage and a controlled switching element in series between such stage and the output
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
A series switching regulator, for regulating a pulsating input voltage 5, has a thyristor 1 arranged to conduct only during periods when the load voltage 4 is such as to cause forward bias of the thyristor 1 before the input voltage increases from zero to a value set by a zener diode 10 and potential divider 7,8. When this value is reached, a transistor 6 shunts the gate circuit of the thyristor 1, thereby preventing it from switching on unless it is already forward biassed and conductive. The pulsating voltage 5 may be derived from an AC source and a rectifier, and two parallel regulators may be used to provide full-wave control of the AC supply. <IMAGE>
Description
SPECIFICATION
A series switching regulator for power supplies
The present invention relates to a series switching regulator for power supplies.
Series regulating circuits for electrical power supplies may be linear regulators which control an output voltage by acting as a variable resistor located between a source of direct input voltage and a load, switching regulators which control an output voltage by acting as a switch located between a source of input voltage, which may be direct, pulsating, or alternating, and a load, the switch closing and opening to a pattern dictated solely by the output voltage, and switching regulators which control an output voltage by acting as a switch located between a source of pulsating or alternating input voltage and a load, the switch closing and opening to a pattern dictated by both the output voltage and the input voltage pattern.
Switching regulators provide certain advantages over linear regulators, including the advantage of greater efficiency due to the fact that, in switching regulators, very little energy is dissipated in the energy flow regulator because of its switching action. Linear regulators, however, have the advantage of simplicity over switching regulators.
It is an object of the present invention to provide a switching regulator of relative simplicity compared with known switching regulators.
In accordance with the present invention, a series switching regulator, for regulating a pulsating input voltage, includes a thyristor arranged in series with an input voltage source and a load, and control means arranged to make the thyristor conductive as the input voltage increases from zero to a set value provided that the output voltage is such as to cause forward biassing of the thyristor by the time that the input voltage reaches the set value. The thyristor remains non-conductive for periods where the input voltage reaches the set value before the output voltage causes forward biassing of the thyristor.
In one arrangement, a capacitor is arranged for connection across a load and connected to the anode electrode of the thyristor, and a threshold circuit is arranged to shunt the gatecathode circuit of the thyristor when the input voltage exceeds the set value, and the value may be set by a zener diode- potential divider combination.
A series switching regulator in accordance with the invention may include a rectifier arranged to permit sensing of an alternating input voltage as a pulsating input voltage.
A series switching regulator, for regulating an alternative input voltage, includes first and second switching regulators, in accordance with the present invention, arranged to operate alternately in synchronism with the alternating input voltage.
A plurality of series switching regulators, in accordance with the present invention, may be arranged together for operation with multiphase supplies.
A power supply may include a series switching regulator in accordance with the present invention and be arranged for connection to a source of pulsating or alternating voltage, or a power supply may include a plurality of series switching regulators in accordance with the present invention and be arranged for connection to a source of multiphase alternating voltage.
Switching regulators, in accordance with the present invention, for regulating a pulsating or alternating input voltage, will now be described, by way of example only, and with reference to the accompanying drawings, in which:
Figure 1 is a circuit diagram representation of a thyristor switching regulator, in accordance with the present invention.
Figure 2 is a circuit diagram representation of a modified arrangement of the switching regulator of Fig. 1, arranged to provide halfwave operation from an alternating input voltage,
Figure 3 is a circuit diagram representation of a modified form of the switching regulator of Fig. 2, arranged to provide full-wave operation from an alternating input voltage,
Figure 4 is a circuit diagram representation of the switching regulator arrangement of Fig.
1, employing a complementary thyristor arrangement to that of Fig. 1,
Figure 5a is a diagrammatic representation of a half-wave rectified (pulsating) input voltage, and,
Figure 5b is a diagrammatic representation of the voltage of the thyristor anode with respect to that of its cathode, in Fig. 1, when the input voltage is as represented by Fig. 5a.
Referring to Fig. 1, a switching regulator, arranged to regulate the supply of current from a pulsating energy source 5 to a load 4 includes a thyristor 1 connected in series with the load 4 and the energy source 5, in the return limb of the energy source: load circuit, with its cathode electrode connected to the energy source 5 and its anode electrode connected to the load 4. A gate resistor 2 connects the gate electrode of the thyristor 1 to the energy source part remote from the thyristor cathode electrode and a capacitor 3 connects the anode electrode of the thyristor 1 to the load part remote from the thyristor anode electrode.The collector electrode of an NPN transistor 6 is connected to the gate electrode of the thyristor 1, the emitter electrode of the transistor 6 is connected to the cathode electrode of the thyristor 1, and the base electrode of the transistor 6 is connected by way of a resistor 9 to the cathode electrode of the thyristor 1. The base electrode of the transistor 6 is connected also, by way of a zener diode 10, to the junction of a resistive potential divider consisting of resistors 7 and 8 connected across the ports of the energy source 5. The energy source 5 may be the combination of a transformer and a half-wave or a full-wave rectifier.
The operation of the switching regulator represented by Fig. 1 may be understood by referring to Figs. 5a and Sb. The output voltage of the energy source 5, represented with respect to time by Fig. 5a, is a half-wave rectified sinusoidal voltage, and the capacitor 3 is initially totally discharged. For the "noload" condition, that is, no current being drawn by the load 4, the thyristor 1 will, by virtue of its gate-cathode connection to the input energy source 5, respond to the first half-wave input pulse by becoming conductive and allowing the capacitor 3 to charge to the peak value of the input voltage. The thyristor anode-cathode voltage is zero or near zero (represented by AB in Fig. 5b) during the charging of the capacitor 3.The thyristor 1 switches off shortly after the input voltage reaches its peak value since the input voltage begins to fall and the capacitor 3 transmits the fall to the thyristor anode electrode as a negative-going voltage (represented by BC in
Fig. 5b). The capacitor 3 loses no charge between half-cycles (represented by CD in Fig.
5b) and pulls the thyristor anode voltage upwards during the next half-wave input pulse (represented by DE in Fig. 5b). The thyristor anode-cathode voltage reaches zero volts at the peak value of the input voltage pulse and remains non-conductive, or substantially nonconductive.
Referring to Fig. Sb, the period EF represents the anode-cathode voltage of the thyristor 1 when a small current is taken by the load 4 between input voltage pulses, the effect of the load current being an exponential rise in the thyristor anode voltage, with the result that on the next input voltage pulse (represented by FG) the thyristor anode voltage reaches zero before the input voltage reaches its peak value. However, the transistor 6 is already conductive and shunts the gatecathode circuit of the thyristor 1, preventing its switching on and allowing the thyristor anode-cathode voltage to follow the input voltage as represented by GH. The periods JK,
KL and LM represent the repeating variations of the thyristor anode voltage at the light load, referred to above.The period MN represents the thyristor anode voltage for a medium/heavy load, where, as is illustrated, the increased loss of charge from the capacitor 3 after the switching off of the thyristor at the time M results in the thyristor anode voltage falling only to the point N from which it rises as the load current continues to be drawn from the capacitor 3. The thyristor 1 becomes conductive (at the time R) before its gatecathode circuit is shunted by the transistor 6 and remains conductive for the period RS which is substantially the entire period of a rectified half-wave pulse, the cycle of events repeating from ST onwards.
Referring to Figs. 1, 5a, and 5b, it is to be noted that, during each half-cycle pulse period, the thyristor 1 is conductive for a period which depends on the rate of loss of charge from the capacitor 3 to the load circuit provided that the thyristor anode-cathode voltage becomes zero before the input voltage reaches a level to cause the transistor 6 to conduct.
The thyristor anode-cathode voltage becomes zero when the input voltage equals the output voltage (represented by the voltage across the capacitor 3). The gate-cathode circuit of the thyristor 1 senses the input voltage, but once the input voltage reaches the level at which the transistor 6 conducts, the thyristor 1 gatecathode circuit is shunted by the transistor 6, and the result is that the thyristor 1 is prevented from conducting during any input voltage cycle in which the thyristor anode-cathode voltage is negative at the time that the transistor 6 becomes conductive.
In the arrangement of Fig. 1 the gatecathode potential of the thyristor 1 is allowed to rise initially with the rise of the sinusoidal half-cycle of input voltage up to a threshold voltage which is set by the division ratio of the resistors 7 and 8 and the conduction threshold of the zener diode 10 and, once the threshold is exceeded, the gate-cathode voltage of the thyristor 1 is held at substantially zero volts by the transistor 6 which is caused to conduct at input voltages above the threshold level. The gate-cathode voltage of the thyristor 1 is again allowed to vary on the falling part of the input voltage half-cycle once the input voltage falls below the threshold value, referred to above, but the thyristor 1 will not conduct because its anode-cathode voltage is again negative.
A characteristic of the arrangement of Fig.
1 is that, under light-load conditions, the thyristor 1 is prevented from delivering short bursts of current to the ioad. The level set by the resistors 7 and 8, and the zener diode 10 is the output voltage of the regulator.
As is explained above with reference to
Figs. 1, 5a and 5b current flow into the capacitor 3 will be intermittent, there being no current flow into the capacitor 3 during periods when its voltage exceeds that of the input energy source 5. The gate circuit of the thyristor 1 is arranged to monitor the input voltage conditions, the gate circuit of the thyristor 1 placing the thyristor 1 in a state to be conductive whenever the input voltage is positive. The transistor 6, the zener diode 10, and the resistors 7 and 8, place a further restriction on the conditions under which the thyristor 1 may become conductive, the condition being that the input voltage should not exceed a preset level.The zener diode 10 and the resistors 7 and 8 determine the preset voltage level by switching on the transistor 6 to shunt the thyristor gate-cathode circuit whenever the input voltage exceeds the preset level. The resistors 7 and 8 set a voltage level and the resistor 9 sets the current level in the zener diode 1 0. The resistors 7 and 8 also set limits for the transistor base current.
As is explained above with reference to
Figs. 1, 5a and 5b, there is a point in the operating cycle at which, in the absence of the threshold-setting circuit, current would begin flowing into the capacitor 3. It is at this time that the thyristor 1 would conduct. With the inclusion of the threshold-setting circuit, the thyristor 1 will conduct if the input voltage is below the threshold value, allowing current flow to the load 4 and the capacitor 3 for as long as the source 5 is able to maintain the flow, and the thyristor 1 will not conduct if the input voltage is above the threshold level. In general, the threshold voltage level will be chosen to be about equal to the required output voltage.
Fig. 2 shows the arrangement of Fig. 1 modified to provide a regulated d.c. supply from an alternating input voltage provided by an energy source 5, in this case, a transformer, the modification being the inclusion of a diode 11 in the thyristor gate circuit in order to limit thyristor conduction to the positive half cycles of the alternating.
In the arrangement represented by Fig. 2, the thyristor 1 acts also as a rectifier for the load: energy source circuit. The regulation action of the Fig. 2 arrangement is as described for the arrangement of Fig. 1.
Referring to Fig. 3, the Fig. 2 arrangement may be used to provide full-wave operation by providing a regulator, as in Fig. 2, for each half of an alternating energy cycle, the two regulators supplying a common load 4 and sharing the capacitor 3. The two regulators operate independently without interfering with each other. The arrangement represented by
Fig. 3 acts as a full-wave bridge rectifier while incurring a voltage loss saving to the load 4 equivalent to a one-diode loss, whereas conventional full-wave systems incur a voltage loss due to two diodes.
The principles applied in arriving at the arrangement represented by Fig. 3 may be used to provide regulation arrangements for multi-phase supplies, the overlap of the supply phases being advantageous in ensuring uninterrupted current supply to the load. As before, the use of multiple substantially independent regulators does not lead to any interference with each others' operation.
Referring to Fig. 4, an arrangement of switching regulator complementary to that represented by Fig. 1, has a thyristor 100 located in the positive supply line between the energy source 5 and the load 4. The thyristor 100, represented by its equivalent PNP/NPN transistor combination is complementary to the thyristor 1, of Fig. 1, in that its gate electrode is located at its anode and rather than its cathode end. The operation of the regulator arrangement represented by Fig. 4 is the same as that of the regulator arrangement represented by Fig. 1, except that its waveforms are inverted with respect to Figs.
5a and 5b. The complementary arrangement of Fig. 4 requires a PNP transistor 60 in place of the NPN transistor 6 of Fig. 1.
Claims (7)
1. A series switching regulator, for regulating a pulsating input voltage, including a thyristor arranged in series with an input voltage source and a load, first sensing means arranged to monitor conditions at the load, the control means arranged to make the thyristor conductive as the input voltage increases from zero to a set value provided that the output voltage is such as to cause forward biassing of the thyristor by the time that the input voltage reaches the set value.
2. A series switching regulator, as claimed in claim 1 for regulating a pulsating input voltage, including a capacitor connected to the anode electrode of the thyristor and arranged for connection to across a load, and a threshold circuit arranged to shunt the gatecathode circuit of the thyristor when the input voltage exceeds the set value.
3. A series switching regulator, for regulating a pulsating input voltage as claimed in claim 2, wherein the threshold circuit includes a zener diode-potential divider combination.
4. A series switching regulator, for regulating an alternating input voltage, including a regulator as claimed in any one of claims 1 to 3 for regulating a pulsating input voltage, and rectifying means arranged to provide a pulsating voltage.
5. A series switching regulator, for regulating an alternating input voltage, including first and second regulators as claimed in claim 4, arranged to operate alternately in synchronism with the alternating input voltage.
6. A power supply including a series switching regulator as claimed in any one of claims 1 to 5.
7. A series switching regulator substantially as herein described with reference to, and as illustrated by Fig. 1, on Fig. 2, or Fig.
3, or Fig. 4, of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB848407942A GB8407942D0 (en) | 1984-03-28 | 1984-03-28 | Thyristor series regulator |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8508138D0 GB8508138D0 (en) | 1985-05-01 |
| GB2157859A true GB2157859A (en) | 1985-10-30 |
| GB2157859B GB2157859B (en) | 1987-11-25 |
Family
ID=10558766
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB848407942A Pending GB8407942D0 (en) | 1984-03-28 | 1984-03-28 | Thyristor series regulator |
| GB08508138A Expired GB2157859B (en) | 1984-03-28 | 1985-03-28 | A series switching regulator for power supplies |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB848407942A Pending GB8407942D0 (en) | 1984-03-28 | 1984-03-28 | Thyristor series regulator |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB8407942D0 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4816821A (en) * | 1986-10-02 | 1989-03-28 | U.S. Philips Corp. | Clocked direct voltage converter |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1163487A (en) * | 1967-11-30 | 1969-09-04 | Masao Horino | Rectified Output Voltage Control Device |
| GB1339953A (en) * | 1970-06-19 | 1973-12-05 | Licentia Gmbh | Stabilized dc supply systems |
| US3939394A (en) * | 1973-09-20 | 1976-02-17 | Sony Corporation | Constant voltage circuit |
| US3947754A (en) * | 1974-06-03 | 1976-03-30 | Motorola, Inc. | Open loop series regulated power supply |
-
1984
- 1984-03-28 GB GB848407942A patent/GB8407942D0/en active Pending
-
1985
- 1985-03-28 GB GB08508138A patent/GB2157859B/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1163487A (en) * | 1967-11-30 | 1969-09-04 | Masao Horino | Rectified Output Voltage Control Device |
| GB1339953A (en) * | 1970-06-19 | 1973-12-05 | Licentia Gmbh | Stabilized dc supply systems |
| US3939394A (en) * | 1973-09-20 | 1976-02-17 | Sony Corporation | Constant voltage circuit |
| US3947754A (en) * | 1974-06-03 | 1976-03-30 | Motorola, Inc. | Open loop series regulated power supply |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4816821A (en) * | 1986-10-02 | 1989-03-28 | U.S. Philips Corp. | Clocked direct voltage converter |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2157859B (en) | 1987-11-25 |
| GB8508138D0 (en) | 1985-05-01 |
| GB8407942D0 (en) | 1984-05-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |