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00:01 Welcome to the spoken tutorial on “Introduction to Single Board Heater System”.
00:06 In this tutorial, we will see the salient features of SBHS,
00:11 block diagram explanation of SBHS.
00:14 The Single-board Heater System is abbreviated as SBHS.
00:19 It is a micro-controller based lab-in-a-box temperature control setup.
00:24 The setup has been designed to cater to the needs of undergraduate & postgraduate control courses.
00:32 It revolves around the concepts of electronics
00:36 Serial port communication
00:38 Micro-controller programming
00:40 Data acquisition interface
00:42 Control theory.
00:44 These concepts serve as the basic foundation for its development.
00:50 Next we shall talk about the salient features of SBHS.
00:55 SBHS is a 3000 rupee device with its hardware design and codes released as open source.
01:03 However, please note that the actual price during purchase may vary.
01:08 An open source software is used to interface SBHS.
01:12 More details can be sought from: sbhs dot os hyphen hardware dot in.
01:19 Moreover, it has a small time constant of around 1 minute.
01:24 Hence, one can do realistic experiment in 10 minutes.
01:29 This setup is also available for remote access under Virtual labs project.
01:35 One can access it remotely and get a feel for it.
01:38 Later, the user can buy it or assemble it and set it up as a lab at a college or at home.
01:46 Figure shows the picture of Single Board Heater System.
01:50 It has an SMPS to generate 12 Volt regulated DC power supply,
01:56 a metal blade and a heater coil is situated below this metal support,
02:02 a computer fan, a display,
02:04 USB and RS232 ports.
02:08 We would now see the block diagram of SBHS.
02:11 The figure shows the block diagram of SBHS.
02:14 It consists of power supply,
02:17 8-bit micro-controller,
02:19 display, fan,
02:21 Heater Assembly, temperature sensor,
02:25 instrumentation amplifier and associated circuitry,
02:29 ISP, serial and USB ports.
02:33 We would now see a brief explanation of the various blocks in SBHS.
02:39 First, we will see the power Supply.
02:42 The power supply is basically a 12V 400 watt SMPS.
02:47 This 12V supply is used directly but most of the circuitry requires 5V supply.
02:54 Hence, separate voltage regulators are used wherever necessary.
02:59 Also, to avoid any ambiguous temperature readings due to power supply fluctuations, the voltage regulators for systems and sensors are kept separate.
03:09 Next is Micro-controller.
03:11 An 8-bit ATmega16 micro-controller is used.
03:15 Micro-controller plays a very important role.
03:19 It controls every single hardware present on the SBHS, directly or indirectly.
03:25 It executes various tasks like setting up communication between computer and SBHS
03:33 controlling the amount of current passing through the heater coil
03:37 controlling fan speed
03:39 reading the temperature value
03:42 displaying parameter values and various other necessary operations.
03:47 Next comes the heater and fan.
03:50 The heater assembly consist of a metal plate placed about 3.5 mm away from a nichrome wire coil.
03:58 When current passes through the coil, the coil gets heated.
04:02 This heat is transferred to the metal plate through convection, increasing its temperature.
04:08 The fan used is a small regular computer fan.
04:12 It is used for cooling the heated metal plate.
04:15 Due to some tried and tested reasons, it is placed below the heater.
04:20 Next comes the Driver block.
04:23 This is nothing but a device which varies the amount of power delivered to the fan and heater.
04:29 MOSFETS are used for the same.
04:32 MOSFETS are operated as per the commands given by the micro-controller.
04:37 These MOSFETS are actually switched at some PWM frequency.
04:42 Now we will talk about the Temperature sensor.
04:45 AD590 is the Temperature sensor used for sensing the temperature of the heated plate.
04:51 The output of this sensor is in micro ampere per kelvin.
04:56 The operating temperature ranges from -55 to 150 degree Celsius.
05:02 Moreover, it does not require any further process of linearization.
05:07 Next we will see Instrumentation amplifier.
05:11 Instrumentation amplifier is used for signal conditioning of the signal generated by AD590.
05:18 It also provides good input impedance for the temperature sensor.
05:23 Hence, the signal generated by the sensor is not attenuated during signal conditioning.
05:30 The Display and Indicators block.
05:33 Display constitutes of a 16x2 LCD display.
05:37 This means that the display is capable of displaying two lines of 16 characters each.
05:44 No separate controller is required since it has its own in-built controller.
05:50 It is used for displaying various parameters like temperature, fan, heater and machine ID (MID) .
05:56 It is operated in 4-bit mode.
05:59 Indicators include various on-board LEDs.
06:04 Next we have Serial Voltage Level Converter block.
06:09 It is used for conversion of signals from serial to TTL and vice versa.
06:15 Next we have USB to Serial Converter block.
06:19 It is used for conversion of signals from USB to serial and vice versa.
06:24 Next we have USB and RS232 blocks.
06:28 It is used to connect the USB and RS232 cable.
06:33 Last we have the ISP block.
06:36 ISP stands for "In-System Programming".
06:39 It is actually a 10 pin male connector.
06:42 Through this, we can program the micro-controller with the help of proper programming device.
06:48 This brings us to the end of this spoken tutorial on Introduction to Single Board Heater System.
06:54 Let us summarize.
06:56 In this spoken tutorial, we saw the salient features and block diagram explanation of SBHS.
07:03 The various blocks briefly explained include: Power Supply,
07:07 micro-controller, heater and fan,
07:09 driver, temperature sensor,
07:11 instrumentation amplifier, display,
07:14 USB & RS232 ports, ISP.
07:19 Watch the video available at the following link.
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07:25 If you do not have good bandwidth, you can download and watch it.
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07:49 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
07:56 More information on this mission is available at:


08:08 This is Rupak Rokade from IIT Bombay, signing off.

Contributors and Content Editors

Nancyvarkey, PoojaMoolya, Sandhya.np14