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    61.
    发明专利
    未知

    公开(公告)号：DE69532699T2

    公开(公告)日：2005-05-12

    申请号：DE69532699

    申请日：1995-06-13

    Applicant: BIO RAD LABORATORIES

    Inventor： RAGSDALE CHARLES W

    IPC: C12N15/00 ,  C12M1/00 ,  C12M1/34 ,  C12M3/00 ,  H03K3/57 ,  H03K17/10

    Abstract: A method for operating a transfection system adapted to deliver a prespecified high-voltage current to a chemical solution, comprising the steps of: asserting a trigger signal when power is removed from the transfection system; triggering a crowbar circuit coupled to a charge storage device that provides the high-voltage current when said trigger signal is asserted; and discharging said charge storage device through said crowbar circuit when said crowbar circuit is activated. An apparatus for directing a first predetermined current profile at a second predetermined high voltage level to a chemical solution is also disclosed, along with a hi-joule switch and a capacitor expansion module.

    AUTOMATIC ELECTROPORATION OPTIMIZATION SYSTEM
    64.
    发明专利
    AUTOMATIC ELECTROPORATION OPTIMIZATION SYSTEM 未知

    公开(公告)号：CA2468750A1

    公开(公告)日：2003-06-19

    申请号：CA2468750

    申请日：2002-12-06

    Applicant: BIO RAD LABORATORIES

    Inventor： RAGSDALE CHARLES W ,  KASTE KEITH ,  HEISER WILLIAM C ,  CHIU TONY ,  MOORE JULIE K

    IPC: C12N15/09 ,  A61N1/30 ,  A61N1/32 ,  C12M1/00

    Abstract: Systems, methods and algorithms for automatically performing optimization of an electroporation system. A system according to the present invention typically includes a cuvette holding assembly (80) configured to hold a plurality of electroporation cuvettes (85), wherein each cuvette includes a first and second electrode, and a shocking chamber (75) configured to hold t he cuvette holding assembly, the chamber having a commutator assembly configure d to provide an electrical contact to the first electrode of each of the plurality of cuvettes in turn. The system also typically includes a control system communicably coupled to the shocking chamber, wherein the control system controls the commutator (100) to automatically contact the first electrode of each cuvette in an order and to provide a potential across the cuvette electrodes when contact is made.

    ARC DETECTION SYSTEM
    66.
    发明专利
    ARC DETECTION SYSTEM 未知

    公开(公告)号：CA2094014C

    公开(公告)日：1999-01-19

    申请号：CA2094014

    申请日：1993-04-14

    Applicant: BIO RAD LABORATORIES

    Inventor： RAGSDALE CHARLES W

    IPC: G01R31/02 ,  G01R15/14 ,  H01T15/00 ,  H02H1/00 ,  H05B3/00

    Abstract: An arc detector for detecting electrical arcs across a break in a line carrying a current in an electrical system. Normally, the line carries current, but when the line is broken, current doesn't flow until an arc occurs across the break. The arc detector detects the break using a current sensor for measuring the current, a filter for filtering out unwanted frequencies, an amplifier for amplifying the remaining frequencies into a substantially square wave, a counter for counting square wave transitions, and a latch to hold a detection signal at an output node when the counter counts a preset number of square wave transitions without being reset by a reset switch or a periodic oscillator.

    69.
    发明专利
    未知

    公开(公告)号：DE68920361D1

    公开(公告)日：1995-02-16

    申请号：DE68920361

    申请日：1989-04-08

    Applicant: BIO RAD LABORATORIES

    Inventor： RAGSDALE CHARLES W

    IPC: G01N27/447 ,  C12M1/00 ,  G01R27/26 ,  G05F1/618

    Abstract: A contour-clamped homogeneous electric field generator having a plurality of electrodes, each electrode being connected to a node which is maintained at a prescribed electrical potential. The electrical potential at the node is maintained by sourcing current into or sinking current away from the node when the voltage at the node varies. The current source comprises a first transistor having an input terminal connected to a voltage/current supply and an output terminal connected to the node. The current sink comprises a second transistor having an input terminal coupled to the node, and an output terminal coupled to the voltage/current supply ground. To control the operation of the first and second transistors, a comparator is coupled to the node for comparing a node-derived voltage to a reference voltage and for providing an oscillating pulse train in response thereto. The duty cycle of the pulse train varies in response to node voltage variation. The oscillating output of the comparator is communicated to an RC circuit which averages the voltages of the pulse train, and the averaged voltage is communicated to a control terminal of the second transistor. When the duty cycle of the pulse train increases, the increased average voltage turns on the second transistor for sinking current away from the node. When the duty cycle of the pulse train decreases, the first transistor turns on for injecting current into the node. The first and second transistors thus maintain the voltage at the prescribed level.

    TRANSFECTION HIGH-VOLTAGE CONTROLLER
    70.
    发明专利
    TRANSFECTION HIGH-VOLTAGE CONTROLLER 未知

    公开(公告)号：CA1330107C

    公开(公告)日：1994-06-07

    申请号：CA616705

    申请日：1993-09-08

    Applicant: BIO RAD LABORATORIES

    Inventor： RAGSDALE CHARLES W

    IPC: H02M9/04 ,  H02M1/00

    Abstract: TRANSFECTION HIGH-VOLTAGE CONTROLLER A transfection high-voltage controller for directing high-voltage currents to a suspension of cells and DNA comprising a control section, a power store, and a highjoule switch Under control of the control section, the high-joule switch direct a high-voltage current from the power store to a load such as a cuvette The high-joule switch comprises a semiconductor controlled rectifier (SCR) having a gate coupled to the control unit for triggering the device, an anode for receiving the highvoltage current from the power store, and a cathode for delivering the high-voltage current to the cuvette A current sink may be connected to the anode of the SCR to render it non-conductive a predetermined time after the high-voltage current appears at the cathode Multiple SCRs may be connected in series to support voltages over 3,000 and currents in excess of 125 amperes, and a trigger control unit may be attached to the gate of each SCR in the series to effect simultaneous or serial triggering of the group.

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