|34||Dryer Temperature Probe
|Joshua Rodriguez (jkr2), Michael Pauls (mepauls2), and Yoon Park (ypark66)
Improper use and maintenance of laundry dryers lead to the accumulation of lint and fabric softener in the dryer vent. Without the removal of this debris, the internal temperature of the dryer would be too high, resulting in dryer fires that could cause substantial property damage and potential bodily harm. A thermocouple could be used to measure the internal temperature of a dryer during its operation and a temperature above 250°F indicates a large accumulation of lint that must be cleaned out. However, such a solution is rather pricy with units costing about $100.
# Solution Overview:
A more cost-effective user-friendly dryer temperature probe can be created by utilizing three components. The temperature probe would be a k-type thermocouple that can withstand and measure temperatures of up to 350°F inside the dryer while it is running. The hardware unit would physically be placed on top of the dryer while it is running to read the data, convert it from analog to digital, and transmit the data via BlueTooth. A smartphone would then be used to view the temperature data in real-time and indicate whether or not the temperature is potentially dangerous. This interface would be more user-friendly compared to the LCD display commonly found on handheld thermocouple temperature sensors.
# Solution Components:
## Temperature Sensor:
This will primarily involve a k-type thermocouple. This will allow the temperature of the lint trap to be accurately read. Then this information will need to be converted from an analog signal to digital. A cold junction compensation circuit must be constructed to bias the thermocouple voltage and properly read the temperature value.
## Power subsystem
This will consist of a 9V battery and a voltage regulator used to power the electronics on the control board as well as the Arduino.
## Control board
This will be made up of an Arduino which will take the thermocouple signal as input, apply conditional logic, and send the resulting information via a Bluetooth module to a smartphone. The hardware will be placed on top of the dryer during operation.
An application on a smartphone with bluetooth capability would be used to display information to the user. Warnings would be displayed if the temperature exceeds a certain value that is deemed dangerous for operation.
# Criteria for success:
- Be able to accurately detect the current temperature in the lint trap within a tolerance of 2-3 degrees Celsius. We can test our prototype with Greg Tucker’s thermocouple sensor side-by-side
- Must be durable enough to withstand dryer operation. The thermocouple itself must be rated properly to operate at up to 400 degrees Fahrenheit which is within the expected operation range of dryers. The physical housing of the circuitry must be sturdy enough to not be damaged by the vibrations from the dryer during operation which could result in unwanted circuit behavior.
- Clearly and accurately depict which temperature zone a dryer unit is operating in real-time. Less than 185 degrees F: The dryer safety sensors are activated needing service (clothes will not properly dry), Blue range color code.
185- 210 Degrees: dryer working optimally (only one cycle needed to dry clothes) Green range color code.
220-250 Degrees: dryer running in yellow range meaning safe but running a little warmer than should be - the dryer should be serviced soon.
250+ Degrees: dryer running hotter than recommended and needs service – as over 250 degrees starts to burn clothing (cotton/wool) red color code.