Abstract:
The present invention relates to a motor drive system which comprises a fan controller circuit operable to generate a PWM control signal for control of a motor speed. The fan controller circuit comprises a current detection circuit and a motor speed determination circuit. The system further comprises a fan driver circuit operable to drive a motor at a duty cycle based on the PWM control signal from the fan controller circuit. The fan driver circuit comprises a current sink circuit operable to draw current from the PWM control signal when the PWM control signal is high and when the motor reaches a predetermined position. In the addition, the current detection circuit is operable to detect the current draw on the PWM control signal and provide an indication signal to the fan speed determination circuit associated with such detection. Further, the motor speed determination circuit is operable to determine the speed of the motor based upon a timing associated with successive current draw detections. The present invention also relates to a method of determining a motor speed which comprises driving a motor at a duty cycle dictated by a PWM control signal and detecting a predetermined rotor position of the motor. The method further comprises generating a current pulse based on the rotor position, wherein the current pulse is convolved with the PWM control signal, detecting the current pulse, and determining the motor speed using successive detected current pulses.
Abstract:
Novel analogs of compounds from the marine sponge Discodermia dissoluta have been prepared. These compounds have been shown to have activity against mammalian cancer cells, and can be used in treating human patients which host cancer cells, including leukemia, melanoma, breast, colon, CNS, renal, ovarian, prostate, and lung tumors.
Abstract:
An internal circuitry protection scheme which protects on-IC circuitry when an external regulator voltage pin is shorted to a higher voltage. The circuit prevents damage to the on-die circuitry that is on the internal voltage rail, by clamping the received voltage, thereby eliminating the chance of damaging the on die circuitry. The circuit offers protection even if the voltage difference is large, but the difference remains small between the internal rail and the external regulated voltage under normal operation.
Abstract:
A computer-based system facilitates exchange of information between users and expert respondents. The users post questions on a topic to a computer bulletin board or forum, using a telephone and modem connection to a remote server. The respondents contact the server by telephone, and receive a list of questions that have been posted. The respondents then dictate answers orally, by telephone, and the answers are recorded and stored by the server as sound files. The stored answers can later be played back by users who connect to the server through their personal computers. The answers can also be transcribed into text files for viewing by the users. Thus, a user can both hear the recorded voice of the respondent and see the stored text of the respondent's answer. The system makes it easy for respondents to answer questions, or provide comments, especially in cases where a respondent is not familiar with computer technology, or where a respondent is not conveniently located near a computer.
Abstract:
A secured network system which will allow only authorized users of the seed network system to access classified data provided by a secured network server. The secured network system includes a readykey controller which has connected thereto a plurality of card readers. A user of the secured network system inserts a microchip embedded card into one of the card readers which then provides an authorization signal to the readykey controller indicating that the user is authorized to use one of a plurality of computers within the secured network system to receive and process classified data. The readykey controller sends an enable signal to a data relay switch enabling a data line associated with the card reader and the computer selected by the user allowing classified data to be transmitted from the secured network server through the data relay switch to the selected computer. Each of the three computers also has a power relay switch connected thereto which is activated by the readykey controller whenever authorization to activate the computer is provided to the readykey controller from another of the plurality of card readers.
Abstract:
A boost regulator circuit includes a rechargeable power supply Vcc, an energy storage component 22 coupled to the rechargeable power supply, a load C.sub.L, and a bi-directional drive means (S1-S6, 20 and 27) for delivering energy from the energy storage component 22 to the load C.sub.L. The bi-directional drive means allows energy transferred to the load to be recovered back to the rechargeable power supply Vcc before switching the load C.sub.L in an opposite direction, thereby effectuating an efficient management of energy and extending the life of the rechargeable power supply Vcc.
Abstract:
An ESD protection structure which includes, preferably a single semiconductor chip, a forward SCR for coupling across a source of potential and a reverse SCR for coupling across the same source of potential which is non-symmetrical to the forward SCR. The breakdown voltage of the forward SCR is different from the breakdown voltage of the reverse SCR. Each of the SCRs has a separate triggering mechanism. None of the anode, cathode and triggering elements of the forward SCR are common to the reverse SCR. A unidirectional device, preferably a Schottky diode, is disposed in the body of semiconductor material between the forward and reverse SCRs to prevent conduction from the body of semiconductor material when the source of potential across the SCRs is reversed.
Abstract:
A testable temperature warning circuit (120) in an integrated circuit substrate (124) provides a warning if the substrate temperature exceeds a critical temperature. A programming circuit (140) controls a selection, circuit (128) to establish a programmably selectable temperature at either the critical temperature or a second predetermined temperature lower than the critical temperature to enable the warning circuit operation to be tested at a temperature lower than the critical temperature. In one embodiment, the selection circuit 128 comprises a current source that produces a voltage drop across the resistor 121 and base-emitter of the transistor 122 produces a substrate temperature indicating current of magnitude related to the temperature of the substrate. The substrate temperature indicating current at the second temperature is extrapolatingly related to the substrate temperature indicating current at the critical temperature. A method is also presented for testing a temperature warning circuit fabricated in an integrated circuit substrate.
Abstract:
Novel lactone compounds from the marine sponge Discodermia dissoluta have been isolated. These compounds and their analogs have been shown to have activity against mammalian cancer cells, and can be used in treating human patients which host cancer cells, including leukemia, melanoma, and breast, colon, CNS, and lung tumors.
Abstract:
An apparatus and method in a data processing system for sending a data packet from a source node to a destination node. The data processing system includes a multi-segment network having at least two segments, wherein the source node and the destination node are located within different segments. Communication of a data packet from one segment to another segment is provided by an agent node. When a receiving node, which may be either an agent or a destination node, cannot accept a packet, it places a reservation tag of "A" or "B" in an echo packet. The retried packet then uses this reservation tag to gain priority for any available buffers in the agent or destination node. The receiving node toggles between accepting all the outstanding "A" packets (when the receiving node is in the "receiving A" state) and accepting all the outstanding "B" packets (when the receiving node is in the "receiving B" state) assuming that the receiving node has a free, unoccupied buffer for accepting the packet. The receiving node counts the number of outstanding "A" reservations and the number of outstanding "B" reservations. Any time the number of available buffers is greater than the number of outstanding "A" packets (when the receiving node is in the receiving "A" state) any "new" packets or "B" packets will be accepted. Analogously, any time the number of available buffers is greater than the number of outstanding "B" packets (when the receiving node is in the receiving "B" state) any "new" packets or "A" packets will be accepted.