Single-Board-Heater-System/C2/Introduction-to-Single-Board-Heater-System/English-timed

Time	Narration
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 requires 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 port block.
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.
07:22	It summarizes the Spoken Tutorial project.
07:25	If you do not have good bandwidth, you can download and watch it.
07:29	The Spoken Tutorial project team: * Conducts workshops using spoken tutorials.
07:34	* Gives certificates to those who pass an online test.
07:38	For more details, please write to contact@spoken-tutorial.org.
07:45	Spoken Tutorial project is a part of the Talk to a Teacher project.
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: [1].
08:08	This is Rupak Rokade from IIT Bombay, signing off.

Contributors and Content Editors

Nancyvarkey, PoojaMoolya, Sandhya.np14