Abstract: A handwash monitoring system and method for providing an alert when a person must wash their hands. A badge worn by a person is activated to register at least one of a visual, audible or tactile alarm by a beacon placed where contamination may occur when the badge enters the range of the beacon. The person must wash their hands according to visual and audible prompts issued by a base unit in a wash area to clear the badge alarm.

Abstract: A voice switched gain system is disclosed for loudspeaking telephone and hearing aid applications involving electret microphones. A voice switched gain circuit comprises an audio pre-conditioning circuit for providing a conditioned audio input referenced to an unconditioned audio input to a compandor circuit. A linear gain level reference generator circuit generates a level for comparison with the audio input level. A decision circuit then controls the compandor operation based on the result of the comparison. The decision circuit either maintains the audio output of the compandor in a compressed state or expands the audio input signal to a higher level expanded state for transmission. Two such circuits are provided in a loudspeaking telephone system, one circuit for maintaining a preemptive near end control through appropriate timing of the dual decision process. Far end control is provided by the other voice switched gain circuit.

Abstract: A frequency oscillator for generating a square wave output pulse train is connected via a frequency divider circuit to a binary shift register which is designed as a divide-by-n counter with m counter stages, wherein m=n/2. Each stage is associated with an output. A resistor network is composed of m rated resistors each of which resistors is connected to a respective register output and in common to an input of a low-pass filter network forming the output circuit. The rating of the resistors is such that an k-th resistor associated with the k-th output of the shift register has the value ##EQU1## wherein R is a reference resistance value;k is a positive integer from 1 through m;C is 1/2 if m is an odd number; andC is 0 if m is an even number.Sine wave forms of different frequencies may be selectively chosen if the frequency divider circuit is provided with parallel inputs which are associated with different dividing ratios and are selectively coupled to the input of the binary shift register.

Abstract: There is disclosed a two- to four-wire hybrid circuit of a telecommunication system. A line coupling circuit, preferably a transformer is connected to a terminal line. Between the coupling circuit and first and second amplifying means each assigned to a receiving branch and a transmitting branch of a transmission line, respectively there is arranged a balancing network composed of an attenuator, a first and a second hybrid impedance. The first impedance connected to the coupling circuit has a value matching the value of a coupled terminal line impedance which is effective at the four-wire side of the coupling circuit. The second impedance and the attenuator interconnect the outputs of the first amplifying means.

Abstract: There is disclosed a high power and/or high voltage switching operational amplifier arrangement having a comparator with a first input for a low frequency AC signal. The output of the comparator is connected with the data input of a bistable element. The bistable element is triggered by a clock pulse signal with a rate substantially higher than the frequency of the AC input signal. An amplifying stage arranged between both poles of a high power and/or high voltage source is composed of a pair of alternately operating switch means, each arranged between a respective pole of the voltage source and a common amplifier stage output. Each of the switch means is coupled by a control input to at least one of the outputs of the bistable element. A low pass filter network coupled to the amplifier stage output forms the output stage of the operational amplifier arrangement. Means for providing feedback are arranged between the filter network and a second input of the comparator.