(formerly Aura Auro Design) – LEARN, GROW, WORK, TEACH
The following class a similar battery model was shown and the children figured out on how to connect the rods ( Cu and Zn ) so that electricity could flow from one bottle to another and so on until the terminals reached the led tower, thus building a small battery unit to power the led up. the children found out that the rods should be kept in series manner to achieve the working of the experiment. They also noted that the copper rods colour was fading eventually with time.
The sixth grade children are super interested when you do something new in class, that’s what happened when we all together build battery models using lemon, copper and zinc rods to produce sufficient electricity to turn on a led 😉 and a digital watch.
At Stem Land we have a huge collection of disentanglement puzzles, and the students decide that they had to figure them out. The atmosphere was covered with low conversations and sudden bursts of joy, suddenly a child will be ‘like yeah i figured it out’ Then the part came when you would become confused again, in order to put it back together the same way it was. This was the tricky part 😉 .
The children and their teacher really enjoyed solving together, so did I 🙂 .
Along with a Sixth Grader, who was interested in medieval times, and so came the thought of building a miniature catapult with him. It consisted of blocks and nylon ropes that acted as the torsional element.
after building it, he tried a few test fires and realised that the distance covered by the load (wooden Ball) was not as expected.
Then a few more twists were added to the rope and the Catapult started to really acquire a huge range in its firing capacity.
When i was a little shorter and a little smaller 😉 ‘Age of Empires’ is what i was into during my week ends.
This was a really beautiful refresher along with Ablilash 🙂 to physically build and learn how the catapult was used to haul heavy pay loads over a distance during sieges in the middle ages.
When your simulation can’t complete and ends unexpectedly….. go to the Simulate/ control panel/Spice .. and change the default integration method to “GEAR” and things should run fine..
The following video demonstrates on how to create a spice model of a component, from a .subckt file which can be acquired from the retailer.
following is a spice model file for a bridge rectifier ; mb6s
data sheet : MB6S_MCC
– Open LtSpice
– Browse for the file and open
– Once opened right click .subckt and create model and design your circuit.
-Ref : http://www.linear.com
The following circuit has a voltage source that operates between 3V and 5V and is connected to the Op Amp’s positive input, across a resistor divider R2 and R1 at the node Va. The simulation is run for 200m secs.
The design is as following: applying super position
Following is the Spice file :Â opamp_gnd
Video :Positive Feedback
LTspice IV is a high performance SPICE simulator, schematic capture and waveform viewer with enhancements and models.
The simulator software can be downloaded from the following link:
ltspice.linear-tech.com/software/LTspiceIV.exe
The following is a circuit on how to use a switch ” .model ” in simulations, it has been created for a RC circuit.
As seen these switches are not a physical model, they require a initial voltage to start to act as one.
20150820_switch_RC is the simulation file for the given circuit, can be seen by installing LtSpice.
Every switch has some instance of resistance when on or off;
Ron = 1Â Â Â Â Â Â Â Â Â Â Â ‘ the resistance when the switch is turned on.’
Roff = 10meg  ‘ the resistance when the switch is turned off.’
Vt   = 0.1        ‘ the instance when the switch turns on’
Classical way to solve the RC filter in time domain :
RC filter classical time domain way
The Deek robot is similar to the Arduino pro mini with a ATmega 328. it has no USB interface. i used the Arduino UNO to program the Deek robot, without removing the micro controller ATmega 328 from the UNO board.
1. Connect the Arduino UNO and upload the program
2. Connect jumpers as follows
Arduino     UNO        –>     pro mini
RESETÂ Â Â Â Â Â Â –> Â Â Â Â GRN
RXÂ Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â RXD
TXÂ Â Â Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â TXD
5VÂ Â Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â VCC
GND Â Â Â Â Â Â Â –>Â Â Â Â Â Â GND
GND Â Â Â Â Â Â –>Â Â Â Â Â Â Â BLK
Arduino     UNO        –>     DEEK_ROBOT
RESETÂ Â Â Â Â Â Â –> Â Â Â Â RESET
TXÂ Â Â Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â TXD
5VÂ Â Â Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â VCC
GND Â Â Â Â Â Â Â –>Â Â Â Â Â GND
GND Â Â Â Â Â Â Â –>Â Â Â Â Â GRD
Now using Arduino UNO as an ISP, from the Tools, Programmer .
and selecting the board as Arduino Pro or Pro mini (5V,16Mhz)w ATmega 328, from the Tools, Board.
Upload the program.
USING FTDI to program;
FTDI Â Â Â Â Â Â Â Â –>Â Â Â Â Â DEEK_ROBOT
RXÂ Â Â Â Â Â Â Â Â Â –> Â Â Â Â TXD
TXÂ Â Â Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â RXD
5VÂ Â Â Â Â Â Â Â Â Â Â Â –>Â Â Â Â Â VCC
GND Â Â Â Â Â Â Â –>Â Â Â Â Â GND
Dt          –>     DTX
Now use AVR ISP, from the Tools, Programmer .
and selecting the board as Arduino Pro or Pro mini (5V,16Mhz)w ATmega 328, from the Tools, Board.
       The frequency and the sine wave was set by the function generator. The input, output wave forms were observed from the CRO. The conditions taken were a 50KΩ , 1KΩ and a current source. The input was fed to the 2.1 speaker’s connector jack to produce the sound of the fed sine wave.
|
Frequency (Hz) |
Input (peak to peak value) |
Conditions |
Output (Peak to peak value) |
Observations |
|
600 |
2 V |
50 KΩ |
0.2 V |
Distorted wave |
|
600 |
2 V |
1 KΩ |
2 mV |
Small signal with distorted wave |
|
600 |
2 V |
Current Source |
100 mV |
Distorted wave |
|
600 |
5.5 V |
Current Source |
300 mV |
Not distorted |
|
600 |
5.5 V |
50 KΩ |
100 mV |
Partially distorted |
|
600 |
5.5 V |
1 KΩ |
5 mV |
Bottom of the wave distorted |
|
450 |
11 V |
1KΩ |
8 mV |
Distorted wave |
|
450 |
11 V |
50 KΩ |
200 mV |
Extremely distorted wave |
From the tabulation the maximum output 300mV is achieved when the input is set to a peak to peak value of 5.5V connected from the current source (PNP BJT’s collector junction ).
To determine the amplification,
the voltage at the base of the NPN transistors is ≈ 2.5V. now divided by the resistance of resistor R6 gives us the current.
 now, the obtained current value multiplied by R5
gives the amplified output ≈ 5V.