GB2095927A - A method of and apparatus for controlling the quantity of electrical energy supplied to a load - Google Patents
A method of and apparatus for controlling the quantity of electrical energy supplied to a load Download PDFInfo
- Publication number
- GB2095927A GB2095927A GB8109450A GB8109450A GB2095927A GB 2095927 A GB2095927 A GB 2095927A GB 8109450 A GB8109450 A GB 8109450A GB 8109450 A GB8109450 A GB 8109450A GB 2095927 A GB2095927 A GB 2095927A
- Authority
- GB
- United Kingdom
- Prior art keywords
- load
- delays
- pulses
- electrical energy
- controlling
- 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
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
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/081—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters wherein the phase of the control voltage is adjustable with reference to the AC source
- H02M1/082—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters wherein the phase of the control voltage is adjustable with reference to the AC source with digital control
-
- 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
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
- H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
- H02M5/22—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M5/25—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc 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
- H02M5/257—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc 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
- H02M5/2573—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc 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 with control circuit
- H02M5/2576—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc 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 with control circuit with digital control
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Electrical Variables (AREA)
Abstract
A circuit for controlling the quantity of electrical energy supplied to a load such as a lamp, comprises a triac output device 12, a circuit 14 for storing in digital form a desired delay (X) in triggering triac 12 from the start of each A.C. half cycle, a detector 20 to sense zero-crossings of the A.C. supply, an oscillator 10 triggered into operation by the detector 20 in each supply half cycle, a counter 16 to count the pulses from oscillator 10, and a comparator 18 which turns on the triac 12 which the count in the counter corresponds to the stored delay (X). In an arrangement for control of multiple loads, (Figure 5, not shown), means (26,28) are provided for sorting and storing the liquid delays in ascending order of divation, and means (24) are also provided for sequentially triggering energisation of the associated loads as the count in counter 16 reaches each delay in sequence. When two or more required delays are separated by then a predetermined number of the pulses from oscillator 10, these delays may be grouped on a common level and the associated loads energised simultaneously. <IMAGE>
Description
SPECIFICATION
A method of and apparatus for controlling the quantity of electrical energy supplied to a load
The present invention relates to a method of and apparatus for controlling the quantity of electrical energy supplied to a load.
More particularly, although not exclusively, the
invention is applicable to the control of a plurality of
electric lights.
One known form of apparatus for changing the control function of an electronic apparatus is disclosed in British Patent Specification No. 1,439,924.
The apparatus disclosed in this Patent Specification
is designed for discotheque lighting arrangements for controlling the power supplied to a plurality of
lights. Such a system included a control module which was selected from a plurality of control
modules in order that the audio output signals could
be used to respond to different control functions set in the control module whereby the plurality of lights were energized according to the control functions stored in the control module.
The system disclosed in the above referred to
Patent Specification used a plurality of triac semiconductor power control elements for driving the
plurality of lamps.
The properties of a triac are well known. A triac is
in effect a bidirectional triode thyristor, so that a single device can control both positive and negative
half cycles of an alternating current waveform. As
shown in Figures 1 and 2 of the accompanying
drawings, a method of controlling the quantity of
electrical energy which is supplied to a load is to
place a triac between the supply and the load in the form disclosed in the above numbered Patent Specification. Control is thus achieved by delaying the
point at which the device is turned on by a period X
(Figure 2). This delay period X is referenced to the
points when the input voltage is zero. A circuit that detects this point is well known and is called a zero voltage crossing of null detector.
It is an object of the present invention to effect such a control of the quantity of electrical energy supplied to a load by digital means.
According to a first aspect of the present invention there is provided a method of controlling the
quantity of electrical energy supplied to a load, which includes the steps of detecting the zero or cross-over points of the A.C. waveform, starting an oscillator on detecting the cross-over point, storing
information relating to the required delay in energiz
ing the load from the start of the half cycle, comparing this stored information with the oscillator output and triggering the energization of the load when equality has been detected between the
required delay and the oscillator output.
Preferably, where there are a number of outputs an additional step consists in sorting these required delays in ascending order in accordance with their
respective magnitudes and sequentially triggering the energization of the associated loads in accordance with the sorted delays.
According to a second aspect of the present invention there is provided a device for controlling the quantity of electrical energy supplied to a load, said device including: means for detecting the zero or cross-over points of the A.C. waveform: an oscillator triggered by said zero detector means for producing pulses for a given period within said half cycle of the A.C. waveform; means for storing information relating to the required delay in energizing the load from the start of the half cycle; means for comparing this stored information with the output from said oscillator; and means for triggering the energization of the load when said comparator means has detected equality between the desired delay and the oscillator output.
Preferably where said device is used to control a number of outputs, means is provided for sorting the required delays in ascending order in accordance with their respective magnitudes, and means is also provided for sequentially triggering the energization of the associated loads in accordance with the sorted delays.
The sorted delays may be stored in the registers of a memory in their sorted order.
Where two or more outputs have substantially the same required delay, these delays may be grouped together on a common level so that the associated load energizing means would be triggered simultaneously.
The present invention will now be described in greater detail by way of example with reference to the remaining Figures of the accompanying drawings, wherein Figure 3 is a block diagram illustrating one preferred way of controlling the quantity of electrical energy supplied to a single load;
Figure 4 is a waveform diagram of the control waveforms in one half cycle of the A.C. supply; and
Figure 5 is a block diagram illustrating one preferred way of controlling the quantity of electrical energy supplied to a plurality of loads.
Referring first to Figure 3, the circuit for controlling the quantity of electrical energy supplied to a load comprises an oscillator 10, and output device 12 consisting of a triac, a circuit 14, in which the desired delay X is stored in digital form, a circuit 16 which counts the pulses from the oscillator 10, a comparator 18, and a zero detector 20 for detecting the zero or cross-over points of the mains frequency.
The zero detector 20 detects each zero or crossover point of the A.C. voltage waveform of the mains, and starts the oscillator 10. The oscillator 10 provides a total of N pulses between the period of just under a half cycle of the A.C. waveform, i.e. for a period which is just less than one hundredth of a second in the case of a 50Hz waveform. The pulse output from the oscillator 10 thus terminates just before the next crossing point. The output level required, is thus expressed as a delay X, of an integral number of pulses on a scale of O to N. This is shown in Figure 4whereto is the width of the pulse output by the zero detector 20, t2 the total period during which N pulses are output by the oscillator 10, and t3 the period between the termination of the oscillator output and the next zero or cross-over point of the A.C. waveform.Thus the total period T of one half cycle of the A.C. waveform is equal to tl + t2 + t3. In practice t1 is small and t3 is negligible.
The N pulses output from the oscillator 10 are applied to the counting circuit 16. The output of the circuit 16 is applied to one input of the comparator 18.
The circuit 14 holds digital information, representing the required delay X before firing. The output from the circuit 14 is applied to the other input of the comparator 18.
When the oscillator is started after the period t1, the count from the circuit 16 is zero, whereas the output of the circuit 14 is some definite value X, so the comparator 18 gives a "0" output. As the oscillator output its pulses, so the value Y increases.
When X = Ythe comparator 18 is triggered to give a "1" output, which energizes the output device 12 to fire the triac and hence supply the load with A.C. The same procedure is repeated during the next and succeeding half cycles, the value of the desired delay
X either remaining constant or changing during each succeeding half cycle according to information fed into it from a circuit (not shown).
In a modified circuit for controlling the quantity of electrical energy supplied to a load, the output from the oscillator 10 terminates after the next crossing point. For example, on a scale of 0 to 100 pulses, the pulses 95 - 100 will occur after the zero crossing point thus creating a "dead" area of control. This method of control has advantages in particular applicatidns.
The above described circuit shown in Figure 3 is only applicable to the case where one load is used or a plurality of loads driven in synchronism are used.
In certain applications it may be desired to drive a plurality of loads independently. This may be achieved economically by the use of one comparator and arranging the required (X1 Xm) in ascending order and then sequentially comparing the delays required with the output of the comparator. An output routing circuit is used to direct the comparator output to the desired output device for individual control of the load.
A circuit for controlling the quantity of electrical energy supplied to a plurality of loads is disclosed in greater detail in Figure 5.
As in the case of the circuit shown in Figure 3, it includes an oscillator 10, a circuit 14, a circuit 16, a comparator 18 and a zero detector 20. In addition it includes output devices 121,122 12m, an output routing circuit 22, a control circuit 24 for selecting the appropriate output device 12 in the sorted sequence of ascending order of delay X, a memory 26 in which the outputs are stored in the ascending order of delay X, a sorting circuit 28, and a circuit 30 for receiving the plurality of required delays from the processed digitalized level information. The sorting circuit 28 sorts these delays in their order of magnitude.These delays X1, X2 Xm are then stored in the memory 26, with the smallest delay XL in the first register of the memory together with information relating to which output it refers and the largest delay XH in the last register of the memory together with information relating to which output it refers. The outputs having intermediate delays between the smallest XL and the largest XH are likewise sorted and stored in respective intermediate registers in the memory, together with the information relating to their associated outputs.
The circuit 14 then sequentially presents the delays from the memory 26 sequentially in the order of storing so that XL is presented to the comparator first and XH last. The comparator then provides a series of outputs as the value of Y increases to reach each of the delay values in turn. The control circuit 24 ensures that the output routing circuit 22 directs the output of the comparator 18to the associated output device 12 for energization thereof. For example if the output level required for the fourth load had the greatest magnitude, the required delay, X4, would be the smallest and the information would be stored in the first register of the memory 22, and the control circuit 24 would ensure that the routing output circuit 22 transmitted the "1" output to energize the output device 124.Thus the m bank of lamps are sequentially triggered on a scale in accordance with the magnitude of the signals.
The system is capable of operating such that in any given half cycle the required delays X, to Xm are sorted into order and stored in the memory 26 during the period t1 that the oscillator 10 is being triggered by the zero detector circuit 20. The required delays may or may not be changed during the next half cycle, but in any event the information must be restored in the memory 26 during the next period t1.
However in practice the time taken to transfer the new data from the memory 26 to the register 14 and to transfer the new output routing information takes a finite time. If expressed in timing oscillator pulses, then the storing time can be expressed as Z pulses, in the same way that the X settings are expressed as a number of pulses between 0 and N.
If two or more output levels are less than Z pulses apart, then there is insufficient time to compare them one at a time. To overcome this problem, the sorting mechanism of sorting circuit 28 groups delays so that they are always a minimum of Z pulses apart, and provides one trigger to all the outputs so grouped simultaneosly.
For example if Z equals 3 pulses and the system has six outputs X1 to X6, the delays being 10, 12, 14, 21,24 and 30 on a scale of 0 two 100, X1 and X2 would be grouped together on a common level of 10, whilst
X3 to X6 would be left separate, since there would now be at least three pulses between each, where Z = 3.
In a practical circuit arrangement of the Figure 5 system, all elements, including the output devices could be included within a microprocessor. In other practical circuit arrangements, the circuit 30 receives the level inputs in the form of a multiplexor and associated analog-to-digital converter which is connected to an interface of the microprocessor. The output devices may also be connected with or without driving circuits, to an interface of the mircoprocessor.
Claims (8)
1. A method of controlling the quentity of electrical energy supplied to a load, which includes the steps of detecting the zero or cross-over points of the
A.C. waveform, starting pulse generating means in synchronism with the cross-over point for producing a series of pulses, counting the pulses so as to give a digial representation of time, storing information relating to the required delay in energizing the load from the start of the half cycle, comparing this stored information with the counted pulses and triggering the energization of the load when equality has been detected between the required delay and the counted pulses.
2. The method according to Claim 1, in the case where there are a number of outputs, including an additional step of sorting these required delays in ascending order in acordance with their respective magnitudes and sequentially triggering the energization of the associated loads in accordance with the sorted delays.
3. A device for controlling the quantity of electrical energy supplied to a load, said device including: means for detecting the zero or cross-over points of the A.C. waveform: pulse generating means triggered in synchronism with said zero detector means for producing a series of pulses for a given period within said half cycle of the A.C.
waveform; circuit means for counting these pulses to provide an output which gives a digital representation of time; means for storing information relating to the required delay in energizing the load from the start of the half cycle; means for comparing this stored information with the output from said circuit means; and means for triggering the energization of the load when said comparator means has detected equality between the desired delay and the counted pulses.
4. A device according to Claim 3, in the case where said device is used to control a number of outputs, additionally including means for sorting the required delays in ascending order in accordance with their respective magnitudes, and means for sequentially triggering the energizaion of the associated loads in accordance with the sorted delays.
5. A device according to Claim 4, wherein the sorted delays are stored in the registers of a memory in their sorted order.
6. A device according to Claim 4, wherein in the case where two or more outputs have substantially the same required delay, these delays are grouped together on a common level so that the associated load energizing means is triggered simultaneously.
7. A method of controlling the quantity of electrical energy supplied to a load substantially as herein described with reference to the accompanying drawings.
8. A device for controlling the quantity of electrical energy supplied to a load, constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8109450A GB2095927B (en) | 1981-03-26 | 1981-03-26 | A method of and apparatus for controlling the quantity of electrical energy supplied to a load |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8109450A GB2095927B (en) | 1981-03-26 | 1981-03-26 | A method of and apparatus for controlling the quantity of electrical energy supplied to a load |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2095927A true GB2095927A (en) | 1982-10-06 |
| GB2095927B GB2095927B (en) | 1984-10-10 |
Family
ID=10520668
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8109450A Expired GB2095927B (en) | 1981-03-26 | 1981-03-26 | A method of and apparatus for controlling the quantity of electrical energy supplied to a load |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2095927B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2556899A1 (en) * | 1983-12-14 | 1985-06-21 | Gen Electric | METHOD AND APPARATUS FOR CONTROLLING THE AVERAGE OF HALF-TIMES OR THE QUADRATIC AVERAGE OF THE LOAD VOLTAGE |
| WO2016154661A1 (en) * | 2015-03-30 | 2016-10-06 | Breville Pty Limited | Control of heating elements |
-
1981
- 1981-03-26 GB GB8109450A patent/GB2095927B/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2556899A1 (en) * | 1983-12-14 | 1985-06-21 | Gen Electric | METHOD AND APPARATUS FOR CONTROLLING THE AVERAGE OF HALF-TIMES OR THE QUADRATIC AVERAGE OF THE LOAD VOLTAGE |
| WO2016154661A1 (en) * | 2015-03-30 | 2016-10-06 | Breville Pty Limited | Control of heating elements |
| US20180115161A1 (en) * | 2015-03-30 | 2018-04-26 | Breville Pty Limited | Control of Heating Elements |
| RU2718156C2 (en) * | 2015-03-30 | 2020-03-30 | Бревилл Пти Лимитед | Heating elements control |
| US11190015B2 (en) * | 2015-03-30 | 2021-11-30 | Breville Pty Limited | Control of heating elements |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2095927B (en) | 1984-10-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4287468A (en) | Dimmer control system | |
| US20130334980A1 (en) | Led light dimming | |
| EP0413441A1 (en) | Radiation generator control apparatus | |
| US4057751A (en) | Controlled dimmer lighting system | |
| US3963945A (en) | Device for producing electrical pulses | |
| EP1767067A1 (en) | Lamp-dimming through bypassing of phase-cutting | |
| US4313061A (en) | Method and apparatus for supplying electric current to a number of electrical loads | |
| GB2095927A (en) | A method of and apparatus for controlling the quantity of electrical energy supplied to a load | |
| EP0502176B1 (en) | Power line communication system | |
| US5256905A (en) | Method and circuit for sequentially connecting plural loads to an a.c. voltage without damaging the low voltage control circuitry therefor | |
| US3710185A (en) | Flasher circuit | |
| US3491263A (en) | Lighting systems with controlled dimming | |
| US6031745A (en) | Time multiplexed power supply | |
| CA2025094A1 (en) | Ballast for supplying a plurality of discharge lamps | |
| US6377164B1 (en) | High powered tri-mode light show | |
| US3323014A (en) | Circuits for firing a plurality of solid state control devices | |
| SU1471174A1 (en) | System for control of heating element | |
| US3624639A (en) | Analogue-to-digital converter | |
| US3699512A (en) | Apparatus for allocating and timing a plurality of load intervals | |
| EP0120103A1 (en) | Circuit for preventing two or more ac switches from conducting simultaneously | |
| WO1996027826A1 (en) | Sequential, differential ignition of series operated arc lamps | |
| SU1626343A1 (en) | Pulse burst generator | |
| JPS58218793A (en) | Dimming device | |
| SU1146781A1 (en) | Device for controlling rectifier converter | |
| US3596171A (en) | Master slave power varying control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |