Abstract: A stimulator for electrically inducing a maximal seizure in a test animal for screening candidate anticonvulsant drugs is disclosed. A stimulator according to this invention includes stimulus generation and control circuitry for generating the stimulus, a display for displaying the duration of three phases of the induced seizure, and user input configured to allow the user to control delivery of the stimulus and to record seizure phase transitions to be displayed on the display. The stimulator may also include a foot switch, electrodes, a computer interface and an optional computer. A method of measuring the phases of an electrically induced seizure is disclosed. A method of analyzing the efficacy of a candidate anticonvulsant drug is also disclosed.

Abstract: A bipolar gate has an output transistor (Q5) that switches in response to the voltage at an emitter of a drive transistor (Q2 or Q10). An active pull-off circuit (14) discharges the base of the output transistor (Q5) when it turns off. The discharge path is provided through a pull-off transistor (Q7) whose collector is coupled to the base of the output transistor. The switching of the pull-off transistor is regulated with a control circuit containing a trigger circuit and a bias circuit. The trigger circuit is coupled between the bias circuit and a collector of the drive transistor. A "kicker" circuit formed with an input transistor (QC1) and a voltage reference (18) speeds up the switching of the drive transistor.

Abstract: A voltage reference for providing a reference voltage (V.sub.AB) between a pair of terminals (A and B) contains a diode (D) and a bipolar transistor (Q) whose base is coupled to one electrode of the diode. The collector of the transistor is coupled to a node (C) between one of the terminals (A) and the other electrode of the diode. The emitter of the transistor is coupled to the other terminal (B).