The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 2000
Filed:
Jun. 06, 1995
David Alan Uhen, Burlington, WI (US);
Eppendorf Netheler-Hinz GmbH, , DE;
Abstract
An apparatus for electroporation stores a level of charge, specified by a user, on a capacitor, which is delivered to a cuvette through an optically isolated high voltage switch. The capacitor is charged through a charging system, including a current mode pulse width modulation control circuit, which monitors the current in the primary winding of a transformer and supplies a pulse width modulated signal, limiting the current on every pulse to a level set by the microcontroller, to the controlling transistor in order to generate the drive to the primary winding of the transformer. A controlled amount of energy is transferred through each pulse to the capacitor. The microcontroller monitors the voltage on the capacitor up to a threshold level to predict the number of pulses necessary to store the requested amount of charge on the capacitor. The microcontroller will then count the number of pulses until the number of pulses necessary to store the requested amount of charge on the capacitor has been reached. At this point the requested voltage is delivered to the cuvette through the optically isolated high voltage switch comprised of sensitive gate SCRs coupled together in series. The voltage and current at the cuvette are monitored and input to the microcontroller so that the impedance at the cuvette is calculated by the microcontroller and errors in the composition of the solution within the cuvette are detected.