As the name suggests, a programmable resistor is a resistor that is changed in value by a test program. The programmable resistor could be a device that plugs into a modular test format such as PXI. It can also be a stand-alone device that is controlled via USB or Ethernet. There are many choices of programmable resistors in terms of range, power, accuracy, and resolution.
For most programmable resistors, the values are changed using relays to short out a series of resistors. The relays could be reed relays, electro-mechanical relays, or solid-state relays. Each of these relay types has different relay chain advantages and disadvantages.
As a portion of a test strategy, replacing actual sensors with simulation can lower costs by creating smaller test systems; for example, if you used actual temperature sensors in test, you will need a heat source to make the sensor react. With so many products containing sensors, sensor simulation is likely to be part of your test strategy as it is often not practical to use the end-product and the integrated sensors in this product as the testbed.
The market for sensors is so large you can be certain that if you are not testing products that incorporate sensors yet, you will be soon. It is estimated that the market for pressure sensors alone will be an almost $12 billion market by 2025 (Source: Grand View Research). The worldwide automotive sensor market will be a $36 billion market by 2023 (Source: Research and Markets). Such market estimates indicate that the technology will be around for quite some time and we need to test the controllers of these sensors.
Check out the webinar below to learn more about these components, their construction, why they are needed, and resistor selection. We'll also explore applications where sensor simulation is an integral part of the adopted test strategies to improve repeatability, reduce test times, and ultimately lower the cost of test.
Looking for more resources on this topic? Browse our Knowledgebase and Resource articles for more information, and download our free white paper, "Understanding Programmable Resistors for Sensor Simulation in Test."