Nathan runs a firm that rents high end amplifiers and sound equipment to musicians, performers and rock bands. While many of his clients hire experienced electricians, others cobble together the equipment and cabling – which could cause equipment to overheat.
The less experienced renters may not be aware of voltage drops and cable run limits across stage floors. Reduced voltage at the remote end creates high internal equipment temperatures and combined with increased ambient temperatures from stage lights, and cables overheating – stage equipment can be damaged or have its lifetime reduced. Sensitive electronic components wear out faster than Nathan expected, meaning increased maintenance and replacement costs – all costs that are passed on to his clients.
Even with careful contract language, how can Nathan monitor and verify operating temperatures to protect his investment or charge when he knows the equipment has been over-heated?
HF RFID Enabled Sensing
Melexis has created the MLX 90129 sensor IC that can be matched with multiple sensor inputs and read with a 13.56MHz Radio Frequency IDentification (RFID) reader from Proxima RF. Using the MLX 90129, a simple, cost effective temperature data-logger could be attached to rental equipment to verified operating temperatures with a handheld reader on rental return.
The read/write sensor IC has an internal temperature sensor and three additional inputs for sensing or monitoring. By combining resistive sensing with passive high frequency (HF) RFID, Melexis opens the door to new sensing applications that previously were difficult to achieve. As a bonus, the HF RFID can use unique product identifiers for inventory and rental control plus can be password protected for added security.
What Can Be Sensed?
The Melexis sensor IC can be used for more than just temperature sensing. Combined with virtually any resistive sensor on up to three sensors or monitoring ports, the sensor IC can provide data through proximity RFID for monitoring applications that include:
– Strain or force sensors to measure small movement, stretching, weight
– Pressure sensors (air, liquid pressure, vacuum)
– Flow (liquid or gas)
– Temperature, humidity
– Electrical voltage, resistance and current
– Tampering, tilting, breaking a seal
– Proximity of nearby objects or linear position
– Shock, rotational speed, angular position, and light
– Run time, duty cycles, on/off
Battery-Less Sensing or Data logging? thermocouple
The combined Melexis 90129 sensor IC and sensors can be encased in a number of different form factors; from tiny, inexpensive plastic housings to water-proof and high temperature enclosures.
The complete sensor can be embedded in equipment or new construction to create an “in situ” battery-less sensing product for taking data at a particular point in time. The low power sensor IC with passive 13.56MHz interface draws power from the HF reader designed by Proxima RF – this energy harvesting means designers can embed sensors in products and equipment where water and liquid are a problem for ultra-high frequency (UHF) RFID.