INTRODUCTION

The Macquirer and PCquirer systems for Macintosh and Windows computers can be used for recording audio and up to 15 other channels containing data such as air pressure and airflow. The system, which is menu driven and very user friendly, consists of both hardware and software. The software can be used for audio alone, without the hardware, by using the built in sound facilities of the computer. The audio data can be analyzed so as to produce spectrograms, pitch and intensity records, and FFT and LPC spectra. Both the audio and the other data channels can be edited, using cut, copy and paste computer techniques. Duration measurements can be made, and a log file that can automatically record duration, frequency and aerodynamic measurements can be created.

The Macquirer and PCquirer software use the normal conventions of Macintosh and Windows applications. There is a cursor that can be used for selecting portions of the data. Holding the mouse button down when none of the data has been selected sets a marker at that point in time on the data.

Macquirer X16 & PCquirer X16 systems (including hardware and software) provide a very compact, portable and unique multi-channel data acquisition system for Mac & PC. The external hardware is a high-speed microprocessor based data acquisition system with a multiplexed A/D shared among all the channels. All the gains and filtering is done through the software and no mechanical intervention is required. The audio channels has been designed specifically for audio (analog input) and the rest of the channels are DC coupled. If you should decide to use audio on any other channels, care must be taken as to remove all the DC components from the signal. Also try to use a very high gain microphone or a pre amplifier to boost the audio signal as much as possible. This way you do not run the risk of overloading the channel with any small DC component.

The front panel is laid out with inputs on the left side and outputs on the right. The DC signal input can be either through the mini jack connections or through the 8pin mini-din (and DB15) connector. The audio input can be either Microphone or Line. The audio output is on headphones or line. The output is active only the left channel.

The channels 1 through 4 have both input mini jacks and 8 pin mini din connectors. If you have a system with more channels, then the extra channels are available only through the DB15 connector and extender box with mini jacks. The extender box provide inputs to the proper channels and also both +/- 5V power for references only. The board has some prototyping area in it for some small electronics expansions. The power is provided for referencing only and current must be limited to 50 ma maximum.

Transducer box option

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The transducer box (if this option is purchased) houses up to 4 highly stable, temperature compensated Pressure/Flow transducers. It includes all the filtering and signal conditioning hardware and very conveniently attaches to Macquirer X16 and PCquirer X16 with a single cable. You can control the offset for each transducer and check the output from the test points provided. There are two ports available for each transducer. The port is for positive signal deflection when air flows in, and negative when it flows out.

Each transducer is either a FLOW or PRESSURE. There is an offset adjustment provided to move the offset as required.

Battery option:

The battery back up is a high current/capacity NICAD battery that will give at least 2 hours of operation with full load. The operation of the battery is totally transparent and will automatically activate in case of the power failure or power removal. The battery is constantly being charged when connected to power and requires no special charging circuitry. Like any other rechargeable batteries, you should fully discharge it before attempting to recharge it again. To discharge, simply unplug the power and turn the device on and wait for about an hour or two after you notice the battery power failure. (NICAD battery voltage will drop very fast as soon as it cannot supply the desire current).

To charge, simply connect to the power, remove the external transducer box (if any), and let it charge for about 12 - 15 hours.