Sample page from the Temperature Sensor/Fan Control User s Manual: TEMPERATURE SENSOR/FAN CONTROL BOARD USER'S MANUAL Introduction: The Temperature Sensor/Fan Control Board is a compact, free-standing circuit module that features two sensing devices: a Vishay NTCLE203E3103SB0 10KΩ, NTC thermistor and a Texas Instruments LM335Z/NOPB precision temperature sensor. The board also contains two dual op amp ICs that allow students to gain valuable experience in sensor signal conditioning. The board contains a MOSFET driver circuit that allows students to control a 12.0VDC fan directly from the module. The fan driver circuitry is controlled by an adjustable op amp Schmitt trigger that allows the students to experiment with a deadband (gap) controller, using either the NTC thermistor or the solid-state temperature sensor as the input transducer. The board is designed specifically for student experimentation, with easily accessible test points and jumper locations. There are five detailed laboratory exercises designed specifically for the Temperature Sensor/Fan Control Board. These procedures are downloadable from pressoncircuitmodules.com (in the form of two lab manuals) upon purchase of the Temperature Sensor/Fan Control Board. layer of the board contains a ground plane, with grounded 0.125" mounting holes in the four corners. These holes allow for panel mounting of the PCB, with possible chassis grounding to a metal enclosure or base plate. Figure 1 contains a silk-screen view of the upper layer of the PCB, clearly indicating the location of each component. Figure 2 uses colors to represent the two layers of the Temperature Sensor/Fan Control Board. 1
Sample User s Manual page with detailed description and illustration of power distribution: Temperature Sensor/Fan Control Board DC Power Distribution: Figure 3 shows the +12.0VDC power bus distribution points for the Temperature Sensor/Fan Control Board. The Temperature Sensor/Fan Control Board is designed to operate from an external +12.0VDC source. The board can receive the +12VDC at two possible connection points. Connector J2, which is a locking DC power jack with a 2.0mm center pin, can receive +12.0VDC from an AC wall adapter with a 2.1mm/5.5mm center-positive connector. Euro block connector J5 allows the user to connect the circuit board directly to a benchtop power supply. As shown in Figure 3, pin 1 of J2 and pin 1 of J5 have a common connection to the +12.0VDC bus. (Refer to Figure 9 to see these components within the system schematic diagram.) If an AC wall adapter is being connected at J2, then both J5 and J4 could be used for daisy chaining +12.0VDC to other circuit boards or devices. Figure 4 illustrates the proper connection of J5 to a benchtop power supply. Figure 3 2
Sample Assembly Guide pages with detailed illustrations and step-by-step instructions: Figure 7 NOTE: PTC1 and PTC2 are not polarized, so these components can be positioned in either orientation. 15) Secure PTC1 and PTC2 in place with painter's tape and solder them into the PTC1 and PTC2 positions. Also trim the component leads and perform a solder bridge check. 16) Referring to Table 3 of the Tables and Figures sheets, remove circuit board indicator LED2 from the Temperature Sensor/Fan Control kit package. Insert the LED into the PCB using Figure 8 below as a guide. 3
Figure 8 17) Secure LED2 in place with painter's tape and solder it into position. Also trim the component leads and perform a solder bridge check. 18) Referring to Table 3 of the Tables and Figures sheets, remove the six two-position non-polarized headers from the Temperature Sensor/Fan Control kit package. Insert these headers into position using Figure 9 as a guide. Figure 9 19) Secure the six headers in place with painter's tape and solder them into position. Also trim the component leads and perform a solder bridge check. 4
Sample pages from the lab exercise covering Deadband Control Systems: 5 Figure 2-5 11) With the multimeter still connected as represented in Figure 2-5, position the hair dryer about eighteen inches away from the thermistor. Blow warm air across the thermistor while observing the display of the IR thermometer. At the exact instant LED1 illuminates and the fan turns on, record the threshold voltage present at TP1 and the temperature values displayed by the IR thermometer in the spaces provided: VTP1 = VDC Temp(RT1) = C = F Is this measured value of VTP1 slightly higher than the set point (threshold) voltage adjusted in step 6? Is this measured value of temperature slightly higher than the set point temperature of 35 C?
Circle the circuit parameter listed below that best represents the value of VTP1 that was just measured: Figure 2-6 12) While the fan is energized, remove the heat source and continue to observe the multimeter and the IR thermometer display. Does the fan appear to be cooling the thermistor? 13) At the exact instant the fan and LED1 turn off, record the threshold voltage present at TP1 and the temperature values displayed by the IR thermometer in the spaces provided: 6 VTP1 = VDC Temp(RT1) = C = F Is this measured value of VTP1 slightly lower than the set point voltage adjusted in step 6?