MMK

I was planning on building a 25lbs Valved Pulse Jet Engine but couldnt figure out how much thick should the tail pipe and the combustion chamber be? Can I use a #25 Gague Mild Steel Sheet rolled out for my given diameter for the same purposes? Will it be enough?? Plz help!

I have been able to calculate orientations using Pololu MiniIMU-9DOF v2 (interfaced with Arduino UNO R3); essentially an AHRS using code found at Github! Now out of curiosity i want to replicate this 3D track as witnessed in this video as below:- http://www.youtube.com/watch?v=6ijArKE8vKU How do I proceed?? what I know is that he used MATLAB for plotting data.......... Plz help!

With Ceramic Coatings I want to achieve higher temperature resistance for the metal parts...... not just these but for the nozzle sections too. Well i havent studied materials yet but they are in my course of studies in the next semester that is why I asked for help! Its my mini-project........!

But It doesnt answer my question regarding how am I gonna use Ceramic Slurry for coating purposes??? Also if I go for Porcelein Enamel is it a good option? If it is how should I proceed???

I have some metal parts of a combustion chamber we fabricated for our Gas Turbine Engine....... Now I want them to be ceramic coated!! How am I gonna do that??? Plz recommend easier ways for the same considering the fact that the equipment around here is not of very high standards!! And also how do I coat the same with ceramic slurry if i get my hands on it!!!! Help me on it!!!

I have an Arduino UNO R3...... I actually wants to interface it with a 6DOF IMU so that I can get visual data on my computer from it........ I am a novice on programming the Microcontroller so plzz provide me source codes and useful links for the same! Also recommend me a good IMU too! >>A code I found on the internet:- #define Gyro_Sens 0.00333 // Gyro sensitivity = 3.33mV/deg/s #define VPQ 0.00322581 // Volts Per Quid --- value of 3.3V/1023 #define ADC_Avg_Num 100.// Number of averaging readings for calibration #define Rad2Deg 57.2957795 // 1 radian = 57.2957795 degrees #define Deg2Rad 0.0174532925 // 0.0174532925 rads = 1 deg //The minimum and maximum values that came from //the accelerometer... //You very well may need to change these int minValx = 403; int maxValx = 610; int minValy = 401; int maxValy = 614; int minValz = 413; int maxValz = 619; //Calibration variables float Gx_Cal, Gy_Cal, Gz_Cal; float GyroRateX=0, GyroRateY=0, GyroAngleZ=0, GyroAngleZ_dt=0; float AccAngleX=0, AccAngleY=0, AccAngleZ=0; float Pitch, Yaw, Roll; int AN[6]; // Hold analogRead data unsigned long pre_time, print_clock=0; float dtime; void setup() { analogReference(EXTERNAL); // sets reference voltage to use voltage applied to VREF pin Serial.begin(115200); delay(300); // Give things time to "warm-up" Calibrate(); // Calibrate sensors pre_time = millis(); //store current time to be used as "previous" time } void loop() { if(millis()-pre_time>=20) // Read ADC and does Calculations every 20ms { dtime=millis()-pre_time; //current time - previous time pre_time = millis(); //store current time to be used as "previous" time dtime=dtime/1000.; Read_ADC(); Calculate(); } if(millis()-print_clock>=50) //print every 50ms { Serial.print(Pitch); Serial.print(","); Serial.print(Roll); Serial.print(","); Serial.println(Yaw); print_clock=millis(); // store current time } //end if } /////////////////////////////////////////////////////////////////////// //////////////////////// Functions /////////////////////////////// /////////////////////////////////////////////////////////////////////// void Read_ADC(void) { AN[0] = analogRead(1); // Gyro_X AN[1] = analogRead(0); // Gyro_Y AN[2] = analogRead(2); // Gyro_Z AN[3] = analogRead(5); // Acc_X AN[4] = analogRead(4); // Acc_Y AN[5] = analogRead(3); // Acc_Z } void Calculate(void) { // Gyro portion //---------------------------------------------------------------- GyroRateX = -1.0*dtime * (((AN[0]*3.3)/1023.-Gx_Cal)/Gyro_Sens); GyroRateY = dtime * (((AN[1]*3.3)/1023.-Gy_Cal)/Gyro_Sens); GyroAngleZ_dt = dtime * (((AN[2]*3.3)/1023.-Gz_Cal)/Gyro_Sens); GyroAngleZ += -1.0 * GyroAngleZ_dt * (1/(cos(Deg2Rad*Roll))); // convert Roll angle to Rads, find sin to use as scaler for Yaw if(GyroAngleZ<0) GyroAngleZ+=360; // Keep within range of 0-360 deg if(GyroAngleZ>=360) GyroAngleZ-=360; //---------------------------------------------------------------- //convert read values to degrees -90 to 90 - Needed for atan2 int xAng = map(AN[3], minValx, maxValx, -90, 90); int yAng = map(AN[4], minValy, maxValy, -90, 90); int zAng = map(AN[5], minValz, maxValz, -90, 90); //Caculate 360deg values like so: atan2(-yAng, -zAng) //atan2 outputs the value of -π to π (radians) //We are then converting the radians to degrees AccAngleX = Rad2Deg * (atan2(-xAng, -zAng) + PI); AccAngleY = Rad2Deg * (atan2(-yAng, -zAng) + PI); // Keep angles between +-180deg if(AccAngleX>180) AccAngleX=AccAngleX-360; if(AccAngleY<=180) AccAngleY=-1.0*AccAngleY; if(AccAngleY>180) AccAngleY=360-AccAngleY; // Final values... Roll = (0.98)*(Roll + GyroRateX) + (0.02)*(AccAngleX); Pitch = (0.98)*(Pitch + GyroRateY) + (0.02)*(AccAngleY); Yaw = GyroAngleZ; } // Reads and averages ADC values for calibration float Avg_ADC(int ADC_In) { long ADC_Temp=0; for(int i=0; i<ADC_Avg_Num; i++) { ADC_Temp = ADC_Temp+analogRead(ADC_In); delay(10); // Delay 10ms due to gyro bandwidth limit of 140Hz (~7.1ms) } return VPQ*(ADC_Temp/ADC_Avg_Num); //Average ADC, convert to volts } void Calibrate(void) { Gx_Cal = Avg_ADC(1); // Gyro_x on pin 1 Gy_Cal = Avg_ADC(0); // Gyro_y on pin 0 Gz_Cal = Avg_ADC(2); // Gyro_z on pin 2 } //////////////////////// //////// END CODE ////// //////////////////////// I found this code from a website....... Will it work if I use it in the below configuration????? And for visualization I use this Altitude Indicator below:- http://www.nuclearprojects.com/ins/attitude_indicator.shtml Plz tell me if all of this stuff will work out......... and if not plz help me in making changes here....... PLZ HELP!!!

I know it sounds like too much but Is there a way I can get live feed of my RC CAR location on my laptop in a google-maps format??? I have seen a build in which they interfaced their GPS module with an 8051 Microcontroller which actually showed the altitude and latitudes of its location on an LCD! Plz Help!!!

yup! it was! Changed the transistor and it worked like a charm!

Thanks everyone....... my circuit is now working fine and its producing sparks too! Thanks for every ones help!!!!!!

Sir I dont know how it happened but my TR1 transistor i.e., C559 is faulty! It was alright when I connected it in the first place! I will buy a new one tomorrow probably and will do further tests and inform u about it! And Sir the answer is no for whether the LED blinks when the circuit is connected to the Coil! And Sir I am using 1N4007 diode in place of 1N4004...... b/c I have plenty of them!

No Sir Step # 3 is a failure! I couldn't light up my halogen lamp........ also that when i connect the LED at the coil terminals with Coil mounted it doesnt blink a bit! not even it lights up! And without the coil......... LED fails to light up when connected at TR1 or Diode or 100 ohm resistor w.r.t ground!!!! What should i do now sir???

I found out that my capacitor at pin 5 was short...... so I just removed it! Now this done I again connected LED at Pin 3 and yes it blinked rapidly!!!! Now Step 1 as well as step 2 stands verified!!! yupeeeee But when I connected my ignition coil to it now, it didnt produced any spark!!! What might be the reason for this???

at primary it was 12 VAC and i am getting 220 VAC at my wall socket @ 50Hz frequency! Sir Step # 01 failed!!!! My LED failed to blink not even a single time....... but when I connect it to pin 4 or even 8 it lights up continuously......... but no blinking at Pin # 03!!!!!!! NOT EVEN ONCE! What should I do now???

Umm Sir isnt it should be pin 3 rather than pin 2? plz tell me.........

Yeah I have ohm tested this coil and i know its perfectly okay! I think this circuit might not be working for me because i might not have used the correct resistors Pin 7 and 2, 6! I used 27k ohm ones in place of 22k ohm!!! What do u all think?? is it might be the problem??? Sir I followed your advice but it didnt worked!! What should I do now??? i am already short on time and this thungy has taken a toll on me!!!! plz helpppppppppppppp!

Okay I will do it today! If anything happens I will surely hit u okie! Btw will it work with just any step down transformer...... whose output is at 12VAC?

It takes both the Resistor and Coil to be disconnected to get the above stated readings! Sir are u proposing to run an ignition coil with stepped- down Alternating Current? I heard that an ignition coil works on pulsed DC! plz elaborate on it! Thanks!

Umm Sorry but I dont intend to use it in a car.......... ! I am a Mechanical Engineering Student and am designing a Micro Gas Turbine......... Wanna use this on that! This 11.86V reading appears only when the 5.6K ohm resistor is disconnected from pin 3 of 555 IC!

Umm do u think my IC has burned or something? plz help its urgent!!!!

No! The Ignition Coil is not metal body bottle shaped one......... Its a standard Suzuki Cultus Coil! @pwagen:- When the Coil was connected with my circuit I didnt get ant potential difference w.r.t ground at pin 3...... but pin 4 and pin 8 shows 12 Volts! All I get is around 2 Volts at the base of transistor BC559 that is after 5.6Kohm resistor at pin 3! Even if I disconnect the whole Pin 3 with the 5.6K ohm resistor I am getting No output at Pin3.......... I am using a Multimeter to check for voltages! But when I disconnected this Ignition Coil from my circuit....... the Pin 3 showed a potential difference of around 11.86 V! Pin 8 and 4 showed 12.26 Volts!.......

I followed this circuit diagram for making my ignition Circuit and connected it to an ignition coil of a car but it does not produce any spark at the spark plug?? Where do I get it wrong??? Also I didnt had 3 in qty 22000 ohm resistors that is why i used 27000 ohm resistors in place of the two resistors connected at pin 2 of NE555 IC! the other 22000 ohm resistor is correct! Also I am using a 12V 80 Amps Car battery for powering this circuit! Plz help me on this!!!!

I have RXTX-433M RF modules........ in order to increase the range b/w the Transmitter & Receiver to communicate........ I plan to make a amplifier......... can a class A amplifier hooked on before the antenna section on Transmitter module will work???? or Class C???? plz give me a good circuit diagram too as I couldnt find one on google! Plz HELP ME!!!!! Remember that the Transmitter & Receiver is used for activating relays and not for any audio signals! i just wanna increase the RANGE of this system!!

Mod I havent seen a single post which will help us in solving this question.........

Q:- The resistances of commercially-available discrete resistors are restricted to particular sets. For example, the available values of resistors with 10% tolerance are selections from the E12 set multiplied by a power of ten from 100 through 105. The E12 set is: E12={10,12,15,18,22,27,33,39,47,56,68,82…} Thus, you can buy 10% resistors with a nominal resistance of 330Ω or 33kΩ, but not 350Ω. Furthermore, the "tolerance" means that if you buy a 10% 390Ω resistor you can be sure that its resistance is between 351Ω and 429Ω. In this problem we need to choose 10% resistors to make a current divider that meets a given specification. Image (Circuit Diagram) could be found out at: http://tinyurl.com/d7yv99y We are given an input current Iin=100μA and a linear resistive load represented by the resistor RL . Our resistive load is not regulated for the high current provided by our current source, so we add a resistor RS in parallel to divide the current such that IL≈40μA. An additional requirement is that the Thevenin resistance as seen from the load terminals is between 60kΩ and 80kΩ. Assume first that the resistors have their nominal resistance. Come up with resistors RS and RL such that the divider ratio IL/Iin is within 10% of the requirement. Of course, the resistances you chose are just nominal. Given that they are only guaranteed to have resistances within 10% of the nominal value, what is the largest and smallest value that VL may have? Find: Rs, RL, VL(max) and VL (min)........

What if I apply an electric arc on black powder........ will ignite it???