Phase Design Announces the Release of
LifeTest Eight™ |
Phase Design ( www.phasedesign.net) is pleased to announce the release of LifeTest™, a state of the art power test monitoring system. LifeTest was developed specifically for testing multiple channels of amplifiers, transducers, and powered loudspeaker systems. The LifeTest system takes ordinary power and accelerated life testing to the next evolutionary step by allowing the engineer to take full control of the setup, event timing, and the monitoring and recording of the current flowing through any Device Under Test (DUT.) In addition, the system can provide a record of periodically sampled Small Signal Parameters thus enabling the analysis of device changes and the projection of its lifespan. For transducers, voice coil temperature can be extracted from the data as well. An optional module adds a set of temperature sensors that can simultaneously track the ambient temperature and/or that of the DUT components. The system has been developed with real world testing in mind. |
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Figure 1. LifeTest Main Screen With Current, Fs, and Re Tracking (single channel filtering). |
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The base system ships with hardware and software to provide stimulus and monitoring of eight channels of devices. The thermal monitor upgrade adds an additional eight channels of temperature data acquisition. The system can also be further upgraded to 16 or 24 channels of DUT monitoring using a single PC running Windows XP or Vista and will be compatible with the upcoming Windows 7 OS.
Blocks of channels can be set up for testing groups of the same DUT, or each channel can have a unique start time, signal, power level, test duration, etc. Blocks or individual channels can be paused for device inspection and the system keeps track of the overall timing so the total test duration is exactly maintained. Previously saved test setups detailing particular test specifications can be recalled for repetitive or ongoing testing tasks.
Any signal that can be saved as a Windows wave file can be used as a test signal. The waves can come from recording of analog equipment or through digital creation using commonly available software tools. LifeTest includes a Signal Generation Module that allows users to quickly create various test signals based on Gaussian noise, multi-tones, tone burst, tone warbles and others. High and low-pass filters with user defined slope and crossover frequency can be applied so external filter networks are not needed. The crest factor and spectral color can be set. There are quick setup routines to create EIA-426B noise (Figure 2) and tone burst signals. Once the wave files are available there is no need for noise generators, CD players, filters, etc… The system is calibrated to output voltage levels entered as part of the test setup. |
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Figure 2. LifeTest Signal Generator Module – EIA 426B Noise Creation. |
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LifeTest can be set up with user defined upper and lower current limits and the system will automatically shut down a channel if a measurement falls outside the window. The limits can be set to auto adjust after a prescribed initial test period. This feature can be useful when the limits cannot be easily calculated, for example when testing with music tracks or other signals with a high dynamic range.
The SSP (Small Signal Parameter) Monitor uses a very brief (< 0.5 second) multitone signal to make a robust third octave impedance vs. frequency measurement at user set time intervals (Figure 1.) A complex curve fitting routine is used to fit the data to a model that yields the device SSPs (Figure 3.) The calculation provides an estimate of the DC resistance that can be used for voice temperature tracking without the need for employing DC coupled hardware and injecting DC current through the DUT. The SSP measurement is fast enough that it does not significantly disturb the test. Other DUTs being tested are not interrupted while the SSP measurement is made. |
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Figure 3. LifeTest Small Signal Parameter Measurement With Curve Fit. |
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Aditional features include power ramp and duty cycle controls. Together these features allow a user to easily determine the power handling capacity and long term operational life for a device. Power on and cool down cycles are independently controlled and the power can be set to automatically increase with each new power on cycle. The high and low level current limits automatically and proportionally adjust when the power is increased. Figure 4 shows a 1 hour on/1 hour off duty cycle with increasing power from 1 to 17 Vrms in 3 Volt steps. |
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Figure 4. Combined Power Ramp and Duty Cycling Features. |
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Testing status can be monitored remotely through email reports or with the LifeTest Remote Monitor tool that provides near real time updates through the internet. An unlimited number of test blocks/channels can be monitored from multiple test stations in multiple locations. On power failures, the system will restart itself as the PC powers up. Testing is resumed automatically and accurate duration timing is maintained. The system sends an email report documenting the down time. |
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Figure 5. LifeTest Status Monitoring. Channel 7 Shut Down for Short Circuit. |
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LifeTest installation and calibration is simple and straightforward. Interface equipment is housed in a robust rack mountable enclosure with all input and output connections on the rear panel. Custom configurations with alternative mounting options are available upon request. |
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Figure 6. LifeTest Interface Hardware. |
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| Phase Design also provides turnkey solutions including power test chamber design, manufacture, and installation. Also offered are state of the art test enclosures for lab and end-of-line use worldwide. For additional information, go to www.PhaseDesign.net or email Bob@PhaseDesign.net . |
