| 摘要 |
The present invention provides apparatus and method for simply and efficiently improving prior art transfection systems. The present invention is a transfection high-voltage controller that provides features for measuring actual load resistance, and compensating for any effects of a limit impedance in series with the load. Additionally, the transfection controller of the present invention measures actual effective capacitance of a storage capacitor, or capacitors, and through use of an expansion module, effectively provides the user with a set of user-selectable capacitors having an effective +/-10% tolerance when the tolerance of the individual electrolytic capacitors is +/-20%. The preferred embodiment incorporates two sections. One section of the system handles 200-2500V and another section handles low voltages (50-500V). The transfection controller includes an improved hi-joule switch that operates in a low-voltage, high-current mode with a low dropout voltage (for use with the 500V (maximum) electrolytic capacitors. Further, additional protective circuitry in the form of a crowbar circuit, will not only prevent charging of the storage capacitor unless a safety switch is operated, charge from the capacitor is shunted to ground should the charging operation be interrupted, or if power is removed from the transfection system.
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