Low Voltage Pulse Research Articles

Possibility of Using a Homopolar Generator as a Pulse Generator

A homopolar machine has been analyzed to ascertain whether it is possible to use it as a high-current, low-voltage pulse generator. A transient expression for the field flux has been deduced and the time constant determined. The effect of the eddy currents produced in the solid metal body of the machine has been included and an expression for the flux density due to eddy currents has been deduced, as well as an expression for the transient current in the magnetizing coil.

Further analysis of sensory coding in electroreceptors of electric fish.

A new category of sensory transducers, electroreceptors, was to be inferred from the work of Lissmannl and Lissmann and Machine2,3 and was directly demonstrated by Hagiwara et al.,4−8 Szabo and Fessard,9,10 and Szaboll in electric fish. Three fresh-water families, the Gymnotidae from tropical America and the Gymnarchidae and Mormyridae from tropical Africa, with many species, all discharge low-voltage pulses from small electric organs more or less continuously into the water, apparently useful in detecting objects, cavities, other fish, and as social signals to each other. The diversity of form of discharge is important. Some gymnotids and perhaps all mormyrids discharge at low (ca. 0–5/sec), irregular frequencies, rising (to 30–100/sec) with excitement. Other gymnotids and the only known gymnarchid discharge at high (300–>1000/sec), regular, species-characteristic, and nearly invariant frequencies. Several gymnotids are intermediate, including the subject of this communication.

Further Analysis of Sensory Coding in Electroreceptors of Electric Fish

A new category of sensory transducers, electroreceptors, was to be inferred from the work of Lissmannl and Lissmann and Machine2,3 and was directly demonstrated by Hagiwara et al.,4−8 Szabo and Fessard,9,10 and Szaboll in electric fish. Three fresh-water families, the Gymnotidae from tropical America and the Gymnarchidae and Mormyridae from tropical Africa, with many species, all discharge low-voltage pulses from small electric organs more or less continuously into the water, apparently useful in detecting objects, cavities, other fish, and as social signals to each other. The diversity of form of discharge is important. Some gymnotids and perhaps all mormyrids discharge at low (ca. 0–5/sec), irregular frequencies, rising (to 30–100/sec) with excitement. Other gymnotids and the only known gymnarchid discharge at high (300–>1000/sec), regular, species-characteristic, and nearly invariant frequencies. Several gymnotids are intermediate, including the subject of this communication.

Inhibitory and excitatory action of the intralaminary thalamus on single cortical neurons

Changes in the spontaneous activity of single cortical motor neurons induced by electrical stimulation of the unspecific mediocentral thalamus with various parameters were investigated with microelectrodes in the anesthetized rabbit. Stimulation with repetitive stimuli of low voltage, low frequency, and long pulse duration, which induces sleep in the waking animal, inhibits 77% of the reactive neurons; simultaneously the average discharge frequency decreases. On the contrary, stimulation at a higher frequency rate (75/sec) producing an arousal reaction activates 60% of the reactive cortical units. On the other hand, progressively longer pulse duration tends to increase the number of neurons reacting with decreased discharge frequency. The fact that the same thalamic substrate may under various stimulation conditions inhibit or activate the cortical neurons, and sometimes even the same cortical unit, provides new evidence for the existence of a functional duality in the mediocentral intralaminary thalamic system.

The response of resistance voltage dividers to steep-front impulse waves

At present there is no generally accepted technique for determining the response of high-voltage dividers to fractional microsecond impulse waves. This paper describes a method which uses a low-voltage cable-type pulse generator and a high-speed oscilloscope as the basic tools. A technique for calibrating the oscilloscope amplifier and the associated input attenuators is described. The effects of such parameters as total divider resistance, divider length, and connecting lead lengths have been investigated. The accuracy and limitations of vertical resistance dividers for measuring steep-front waves are evaluated.