摘要:
An integrated circuit configurable as a transmitter/receiver includes learn capabilities that allows a receiver IC to memorize the identification pattern of a specific transmitter.
摘要:
A remote control access system uses a transmitter and a receiver. The transmitter generates an encrypted identification code which the receiver decrypts and grants access to the system if the decrypted code matches an identification code stored in the receiver. The encryption occurs by taking a 40 bit identification code and forming 5 bytes (8 bytes each). The 5 bytes are logic exclusive OR'd to form a 5 byte wide encrypted code. Decryption occurs by performing the opposite exclusive OR operation on the 5 byte wide encrypted code to convert it back to the 5 byte identification code. The 4 most significant bytes of the decrypted code are compared against the 4 most significant bytes of the previous stored decrypted code in the receiver. If the comparison yields a zero, this means the least significant byte will be within 2.sup.8 or 256 of each other and access will be granted.
摘要:
An integrated circuit configurable as a transmitter/receiver includes learn capabilities that allows a receiver IC to memorize the identification pattern of a specific transmitter.
摘要:
An integrated circuit (IC) configurable as transmitter/receiver includes a method of preventing unauthorized learning and reproduction of an access code as a security measure. When the IC is configured as a receiver and placed in the learn mode, a flag is set in a memory of a microcontroller. If later configured as a transmitter, the microcontroller checks the flag upon power up and if the flag is set, the stored code is randomized so transmission of it is impossible.
摘要:
A transmitted data stream in a remote control system is a serial data stream having a synchronization sequence and a data sequence. The data sequence is encoded into a symbol comprised of a series of data bits wherein a 110 may represent a logic 1 and a 011 may represent a logic 0. A self adaptive filter adjusts its gain and offset to determine the duration of one bit. Providing a serial code format wherein the synchronization sequence has a smiller duty cycle as the duty cycle of a symbol aids the self adaptive filter to set its threshold switching level accurately and quickly, thus aiding the receiver to decode the transmitted data stream.
摘要:
Polyurethane foam-fiber composite structures comprising a flexible polyurethane foam uniformly mixed with a fibrous material and bonded with a liquid flexible resinous binding agent to provide a cured foam structure; the relative amounts of materials in the foam structure being such that for each 100 parts by weight of polyurethane foam particles about 10 to 500 parts of fibrous material and about 10 to 250 parts of binding agent is employed, the fibrous material having a fiber length of from 1/8" to 4" and preferably 1/4" to 3/4", a density of at least 0.75, and a diameter of less than 500 microns. The foam structures have an excellent sag factor with good resiliency for a select density.
摘要:
A continuous process for reusing scrap polyurethane involves the following stages: Chips of thermoset polyurethane foam are supported as a bed; the bed of chips while moving is heated; the bed of chips while moving is subjected to pressure or compression; and a web is formed. The resulting material is useful in many industrial applications, including padding, gaskets, and insulation.
摘要:
Polyurethane foams based on reactive polyols and polyisocyanates containing a filler are modified with an organofunctional silane containing a hydrolyzable group and an ethylenically unsaturated linkage. The polyurethane foams have improved physical properties including improved stability, compression set, tear resistance, elongation, and tensile strength.
摘要:
An improved method for manufacturing a foam-filled polyurethane foam bun from foam particles having uniformly dispersed therewith large amounts of solid material bonded together with new polyurethane foam is described. The method comprises uniformly applying a liquid flexible polyurethane foam-forming material to a dispersion of foam particles and solid material to provide a blend, distributing the blend within a mold, and foaming and curing the foam-forming material by a plurality of steaming steps wherein the mold is flipped from a first to second position between steaming steps. The foam buns have a uniform density gradient. Foam buns are disclosed having a variation in density across the foam bun. There is also disclosed an improved char-forming foam obtained as a result of using boric acid in the foam-forming formulation.