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Description
The QA451 is designed for high-speed testing of amplifiers. If you are testing at the module level (with modules designed for single supply operation), the QA451 allows the on/off control and current measurement of the supply rail. The QA451 is a companion product to the QA403 Audio Analyzer. When combined, the products work together to ensure fast, repeatable automated measurements of audio power amplifiers up to several hundred watts.
Features
- Programmable 4/8 Ω load
- Fully isolated from PC
- USB powered
- Up to 200 W for 220 mS
- DC Current Sensing
- Integrated 6th order LPF
REST Interface
The QA451 can be controlled manually from a PC application or controlled using a web-based REST interface.
Measuring Current
The QA451 allows low-cost external fixed-voltage supplies to be used to power your amplifier during test – dramatically reducing your investment per test bay. The QA451 integrates a high-side switch, enabling on/off control of the supply to the amplifier. When turning on the supply, a momentary soft-start circuit ensures the amplifier-under-test isn’t exposed to high currents that might overstress components. And during operation, the QA451 provides an isolated current measurement, allowing up to 15 A (peak) of DC current to be measured with 10-20 mA of resolution. This permits automated efficiency measurements to be easily made – a primary predictor of whether the amplifier was assembled correctly.
4 and 8 Ω Loads
The QA451 provides both 4 and 8 ohm resistive loads. The loads are thermally protected using fast, high-accuracy digital thermal sensors ensuring that fault conditions won’t damage the QA451.
