 Method and tunnel type furnace for calcining carbonaceous bodies, in particular electrodes |
| This invention is directed to improve the methods and tunnel type furnaces therefor, as indicated ... |
|
| Pressure pad for stably floating thin strip |
| Accordingly, it is one of the principle objects of the present invention to provide a flotation ... |
|
| Bottle stopper means for wine bottles |
| We claim as our invention: 1. Stopper means for closing wine bottles and like receptacles including ... |
|
| Space heater |
| This invention relates in general to space heating and, more particularly, to certain, new and ... |
|
| Air heater |
| I claim: 1. An air heater comprising a pipe assembly, said pipe assembly having an intake pipe ... |
|
| Disposable catalytic heater |
| OF THE INVENTION There is shown at 10 one form of the complete, assembled catalytic heater of this ... |
|
| Franklin stove attachments |
| Having thus described our invention, what we claim is: 1. A stove, comprising a frame having ... |
|
| Olefin polymerization catalyst |
| OF THE INVENTION The novel catalyst systems of the present invention are prepared by depositing, ... |
|
| Air climatizing device |
| It is a primary object of the present invention to overcome the aforementioned drawbacks and to ... |
|
|
Circuit having improved firing angle symmetry for ignition pulses in the control of a multipulse rectifier
| Details |
Inventors: Weibelzahl, Manfred; Meusel, Wolfgang; Schaumman, Kurt;
Assignee: Siemens Aktiengesellschaft (Berlin and Munich, DE)
Primary Examiner: Shoop; William M.
Assistant Examiner: Wong; Peter S.
Attorney, Agent or Firm: Kenyon & Kenyon
Ignition control signals for a multipulse controlled rectifier are combined in a sequence which is fed through a first time delay stage to a phase control circuit having a voltage-controlled oscillator which generates a phase-locked, gated, highly accurate square-wave oscillation as a trigger pulse series. The ignition control signals and the trigger pulse series of the voltage-controlled oscillator are conjunctively coupled in and gates are then amplified to form firing (ignition) pulses. A second time delay stage is provided for safety, in the event of dynamic control processes, and follows the first time delay stage. The output signals of the second time delay stage are linked to the ignition control signals in additional and gates and are subsequently amplified. Should the phase control circuit be unable to follow the changes of the ignition control signals in the event of dynamic changes in the control processes, the ignition pulse formed after the response delay of the second time delay stage is utilized. |
|
DETAILED DESCRIPTION According to the invention, this problem is solved in a circuit having the following elements: (a) means for forming a control signal sequence from the ignition (firing) control signals; (b) means for delaying the control signal sequence by predetermined time, corresponding roughly to the greatest possible asymmetry of the ignition control signals; (c) means for forming a highly accurate series of trigger pulses from the delayed control signal sequence which is phase-lock linked to the delayed control signal sequence; and (d) means for the conjunctive linkage of the ignition control signals to the series of trigger pulses.
The invention is based on the premise that, in a control unit for a multipulse recitifier, the ignition control signal control signals, which are determined by comparison of the periodic reference output voltage of an oscillator controlled by a clocking AC voltage with a DC control voltage, are subjected to certain inaccuracies respecting the time intervals of their rising flanks.
Despite these inaccuracies of the ignition control signals, it is desirable for the ignition pulses of the controlled valves to be as equidistant as possible.
To this end, the ignition control signals are first combined into a control signal sequence in which the time intervals between the rising flanks of successive pulses are likewise subject to such an inaccuracy.
This control signal sequence is delayed and energizes, as a delayed control signal sequence, a phase control circuit which derives a trigger pulse sequence of the same frequency.
The trigger pulse sequence is phase-lock-linked to the delayed control signal series fed to it and the time intervals of the rising flanks of successive pulses are equidistant with extremely great accuracy.
The actual ignition pulses are now obtained by conjunctive linkage of the original ignition control signals to the trigger pulse sequence of the phase control circuit, and by their subsequent amplification.
Each start of an ignition pulse is determined by the rising flanks of the trigger pulses of the phase control circuit
|
| Related patents |
|
|
Power converter apparatus
What is claimed is: 1. A power converter apparatus for effecting power conversion between an a.c. system and a d.c. system by using a full-wave bridge circuit in which ...
|
|
|
Power factor correction for variable speed drive
The system employs means to vary the amplitude of the voltage in the positive and negative rails to improve the power factor. An amplitude switch is located in one of ...
|
|
|
Wiring system for electrically operated devices comprising heating resistances
What is claimed is: 1. A heating arrangement comprising: first and second junctions connectable to a power source, a heating resistance having first and second terminals,...
|
|
|
Circuit for the parallel coupling of audio frequency central-control transmitting stations in a wave band filter construction
When using an audio frequency generator of the electrodynamic rotary type or a static forcibly commutated inverter, the resonant circuits C.sub.s, L.sub.s and C.sub.1, L...
|
|
|
Reference point potential compensating circuit for use with phase controller
OF PREFERRED EMBODIMENT Referring to FIG. 4, the primary side of a transformer T.sub.1 is connected to a power supply N and the secondary is connected to a resistance R....
|
|
|
Manual control device for a watch movement
It is an object of the invention to provide an analagous device, but of considerably simpler construction. It results from the distinguishing features of the manual ...
|
|
|
Demand drive component
Accordingly, the above problems and difficulties are obviated by the present invention which provides a novel drive puck for use in driving a film roller in a positive ...
|
|
|
Thermoforming apparatus
According to the invention, there is provided apparatus for manufacturing articles by thermoforming in which a preheated sheet of thermoplastics is intermittently fed to ...
|
|
|
Apparatus for continuous heated pressing of material in sheet form
OF A PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown, in perspective, apparatus in accordance with the present invention. In FIG. 1, there is shown the ...
|
|
|
Floating equipment and floating-type heat treating furnace for striplike works
OF THE DRAWING With general reference to the drawing for like parts, and specific reference to FIGS. 1 and 2, there is shown an improved pressure pad B which is made in ...
|
|
|
Heat Accumulators 
