A method of synthesizing load invariant switch-mode power converters comprising positive current feedback of an exactly specified nature and value of its transfer function is presented. The system transfer function independent of load is realized while the stability and dynamics of the system are controlled by an additional voltage loop. The development of the proposed method, computer simulation results, and experimental results are also presented. >

Synthesis of load-independent switch-mode power converters

An optical line terminal which sends and receives messages or data to/from optical network units (ONUs) connected thereto. A cyclic message monitor produces a trigger signal, for use in a PLOAM grant generator, at certain intervals in harmonization with upstream messages that a specific optical network unit regularly transmits. A downstream message monitor watches outgoing downstream messages to detect a certain message requesting an ONU to return a response, and it triggers the PLOAM grant generator if such a message is detected. An upstream message monitor detects an upstream message whose identification code indicates that the sending ONU has no information to return. If such an upstream message is found, it limits the issuance of PLOAM grants to that optical network unit. The PLOAM grant generator produces PLOAM grants which permit ONUs to transmit their messages, and sends them out through a PLOAM cell transmitter.

Optical line terminal

The switching regulator includes a first regulation arrangement (1) for a voltage regulation and a second regulation arrangement for a load current regulation, which comprise respectively two inputs and respectively one output. A reference signal (2) is supplied to a first input of the first regulation arrangement and a second input is supplied with an output signal (3) of the switching regulator. The output of the first regulation arrangement is coupled with a first input of the second regulation arrangement (5). At least one power switch (12) is provided, which is controlled through a control signal (11) of the second regulation arrangement, and which comprises a load path arranged between a first pole with a first supply voltage (13) and a second pole with a second supply voltage (14). An inductance (15) is arranged in series to the load path, and an integrator (19) produces a regulation signal (40) representing a load current (22) by integrating the voltage (18) on the inductance, which is supplied to a second input of the second regulation arrangement.

Current-mode switching regulator for power supply

The object of the invention is to provide an error amplification
circuit for matching an output voltage from a DC-DC converter with its
target value, wherein the DC-DC converter is prevented from generating
excess output even when the reference voltage provided as the target value
varies stepwise An error amplification circuit is configured by cascading
together an operational amplification circuit 6a and a PI control circuit
6b, both having a fixed operation point (ground potential), so that even
when the reference voltage V REF is varied stepwise, the operation points
of the circuits 6a and 6b maintain the ground potential The above object
is thus achieved

PWM Control circuit for DC-DC converter

A switching regulator generates controllable pulses from a primary d-c. voltage source and then smooths the pulses to form a d-c. output that varies according to the changes in the pulses. A reference voltage source establishes a d-c. reference signal that varies in magnitude with any variations in the magnitude of the d-c. output but with a substantially constant differential in magnitude between the reference signal and the d-c. output. A voltage or current sensor generates a signal that varies in accordance with changes in the voltage or current level of the d-c. output, and a comparator detects the difference between the reference signal and the signal from the sensing means to produce a control signal that varies according to changes in the difference between the two signals. The pulses that form the d-c. output are adjusted in response to the control signal to maintain the output at a regulated voltage or current level. An auxiliary internal power supply is provided for the reference voltage source and the comparator and the current flow is returned through the reference voltage source and the comparator to the auxiliary internal power supply to minimize power losses in the reference voltage source and the comparator. A predetermined d-c. dry voltage is superimposed on the d-c. voltage from the primary source and floats with respect to the reference signal and the d-c. output.

High efficiency switching regulator

The regulated mains power supply with phase-shift correction comprises a rectifier (1) with mains input (2) whose output is connected to a controlled switch (4). The switch is followed by an L-C low-pass filter (6, 7) bridged by a diode (8). The load (10) is connected across the filter output. The output is taken to an adder (13) having a reference input (15) and whose output is taken to a PI controller (12). The controller output is taken to an adder (16) which has an input taken from the filter input (18) via a smoothing circuit or integrator (17) having a first-order phase-shift. The adder output is taken to a proportional controller (19). The controller output drives the switch (4). The multi-loop control system provides an optimum phase margin of +90 deg. with which to compensate the phase-shift due to the low-pass filter.

Regulated mains power pack with phase:shift correction - has multi-loop control system with proportional differential action

The clock pulse signal unit is based on the principle of 'pulse-inversion' The primary winding of a transformer is connected up to a DC potential supply via two variable controlled semi-conductor switches and is subject to current flow in either direction through the windings The secondary winding is connected to output terminals via a current rectifier and smoothing filter Part of the winding (W1) of the transformer (W) is bridged by a series-circuit, containing resistances (R1-R9) and a demagnetising semiconductor switch (S5) The demagnetising semi-conductor switch (S5) is connected up to one of the semi-conductor switches (S1-S4) after each switch-in period The series resistor (R1) circuit and the demagnetising semi-conductor switch (S5) lie parallel to the primary winding (W1) A choke (DR) is located between the DC voltage source (UE) and the semi-conductor switch (S1-S4) The smoothing filter consists of two capacitors (C2, C3), which lie parallel to the output terminals (A1, A4)

Clocked pulse signal unit - has transformer winding bridged by series resistor circuit and has de-magnetising semiconductor switch

Die Erfindung betrifft ein Mehrprozessorsystem (1-5) im Rahmen einer speicherprogrammierbaren Steuerung. The invention relates to a multiprocessor system (1-5) in the context of a programmable logic controller. Die Zugriffsreihenfolge und die Zugriffsdauer (T i ) der einzelnen Prozessoreinheiten (1-4) zum gemeinsamen Bus, uber den die Signale vom und zum gesteuerten Prozes laufen, sind in einer Buszuordnungsmatrix festgelegt. The order of access and the access duration (T i) of the individual processing units (1-4) to the common bus via which the signals to and from the controlled process run are set out in a Buszuordnungsmatrix. Hierdurch ergibt sich eine einfache Synchronisation der Prozessoreinheiten; This provides a simple synchronization of the processor units; ferner ist die Einhaltung garantierter Reaktionszeiten hinsichtlich des Prozesses moglich. Furthermore, compliance with guaranteed response times in terms of the process is possible.

Gautam Tendulkar

Papers

Regulated mains power pack with phase:shift correction - has multi-loop control system with proportional differential action

Clocked pulse signal unit - has transformer winding bridged by series resistor circuit and has de-magnetising semiconductor switch

Stored-programme control