11 results about "Control logic" patented technology

A hand-held token for secure conveyance of encryption keys includes memory for holding a media key and at least one device key. Control logic reads the media key from memory, encrypts the media key based on the device key, and transmits the encrypted media key to a data storage device. The data storage device decrypts the encrypted media key using its own device key, which may have previously been downloaded from a token.

A class D amplifier with output DC offset protection is disclosed. The DC offset protection receives a PWM input signals from the outputs and investigates the PWM output signals whether there is a large DC voltage difference is being reflected on the speaker load. If so, shutdown signal SD will be sent by the DC offset protection to the PWM control logic and gate driver, thus, shutting down the output of the class D system and preventing disastrous condition from being develop across the speaker.

The invention discloses a circuit and a method for correcting the direct current (DC) offset part in output signals of a signal processing unit. The DC offset correcting circuit comprises a 1 bit quantizer, a control logic unit and a digital-to-analog converter, wherein, the 1 bit quantizer is coupled to the output terminal of the signal processing unit and used for receiving and detecting the DC offset part in the output signals so as to obtain quantitative information. The control logic unit is coupled to the 1 bit quantizer and used for sequentially setting one of a plurality of bits of a compensation value and updating the set bit according to the quantitative information. The digital-to-analog converter is coupled to the control logic unit and used for compensating the DC offset part in the output signals of the signal processing unit according to the compensation value.

The invention belongs to the technical field of information security of an industrial control system, and particularly relates to an industrial control system information security implementation method based on an FPGA virtual DCS. The method comprises the following steps of 1, according to the requirements of a virtual DCS application, all algorithm block and function blocks are realized by an FPGA chipset and become an entity large-scale digital logic circuit set; 2, a virtual DCS on the FPGA chip and a real DCS performs computation synchronously in parallel; 3, it is determined whether theoperation result of the virtual DCS on the FPGA chip and the operation result of the real DCS control system are consistent, it is determined that the system is not secure if not, and it is determinedthe system is secure if so. The method provided by the present invention can determine whether the system is safe according to a correct control logic operation result of the virtual DCS not subjectto the network security threat.

The invention provides an explodent elimination circuit. The explodent elimination circuit is used for explodent elimination during power on and power off of an output node of an audio digital-to-analog converter, and comprises four resistors, three positive channel metal oxide semiconductor (PMOS) transistors, two negative channel metal oxide semiconductor (NMOS) transistors, a comparator, a pull-up current source, a pull-down current source and a control logic module, wherein the pull-up current source and the pull-down current source slowly charge the output node or provide a discharge path and can effectively eliminate the explodent of the output node during power on and power off; and the adjustable voltage rise speed and voltage drop speed of the output node are ensured by a current source structure and feedback control. The invention has the characteristics that: the explodent elimination circuit can be widely applied to a power amplifier at the rear end of a single-bit audio digital-to-analog converter, a multi-bit audio digital-to-analog converter or the audio digital-to-analog converter, and can effectively eliminate the explodent caused by abrupt power on or power off of the output node of the audio digital-to-analog converter; the voltage rise time and the voltage drop time of the output node are controllable, complicated control logics are unnecessary, and the power consumption is low.

The invention relates to the technical field of elevator control, and provides a signal control method and device of an elevator system, the elevator system and a storage medium. The signal control method can comprise the steps that a common input instruction is received through a control system; when the control system responds to the common input instruction, a control signal flow correspondingto the common input instruction is continuously output to an actuator of the elevator system through a signal output channel; the signal output channel is formed between the control system and the actuator; and when a safety system receives a safety input instruction in the continuous output process of the control signal flow, the signal output channel is blocked so as to interrupt the continuousoutput process, and then the signal control logic of the elevator system is further simplified.

The invention relates to the technical field of power grid stability control, and particularly relates to a power grid stability control method suitable for an abnormal condition of an enterprise power grid. The power grid stability control logic is established according to the component fault tripping type, and the method comprises the following steps of S1, judging component fault tripping; S2, judging component fault tripping type; S3, determining various power parameters before and after fault tripping according to the fault tripping type determined in the S2; and S4, establishing a mathematical model for the power parameters obtained in the S3, and carrying out logic analysis, and realizing stable control under the abnormal condition of the power grid.