## Posts

### Capacitors: Calculations & Simulations on Charging, Discharging Time & Voltage Assume charging a completely discharged capacitor, under resistance, R with an applied potential, E having the capacitance, C. Potential across the capacitor is E c . At time, t = 0s or t o :   E C < E; E C = 0 V. If it is fully charged then E C = E and t = t c . ‘E’ is the maximum potential attained by the capacitor. Time to reach maximum potential is: (t c – t o ).   At any given time, ‘t’ on charging in between t o and t c the potential of the capacitor, E C is related to the maximum potential, E by the relation, where ‘t’ is the elapsed time during charging ‘R’ is the resistance in Ω ‘C’ is the capacitance in F.   The product of R and C is called the time constant and is represented as, τ. So, τ = R × C.   Unit for τ τ = R × C = Ω × {F} = Ω × {C × V –1 } C = Charge in Coulombs = A × s = Ω × {A × s × V –1 } = = Ω × {V × Ω –1 × s × V –1 } = s. At one time constant, capacitor is 63.2% charged. I

### NSE live BANK NIFTY option chain data in Excel sheet Get the Live NIFTY Bank Index Option Chain Data in Excel Sheet for CE & PE. Bank Nifty Trend can analyzed from this Excel based on Change in Open Interest, Price and Volume. Fetch the various data such as Last Traded Price (LTP), Open Interest (OI), Change in Open Interest (%), Change in Price (%), Total Volume Traded, Buy Volume, Sell Volume, Implied Volatility (IV), etc., for both Calls and Puts. A simplified Excel sheet for traders of Bank Nifty Index, coded in VBA, to fetch the real-time NSE BANK NIFTY option chain price data with different expiry dates and at a few strike prices from the underlying price. Analyze in-depth for the changes in Open Interest (OI), Changes in Price as well as the Buy, Sell Volumes, Total Volumes Traded etc., at a few different strike prices with At the Money (ATM).  Screenshot Designed by, Dr. M Kanagasabapathy Important Disclaimer: This Excel Sheet is designed for educational purposes only.  Either this web page or the Administrator of this web p

### Laptop Battery Life Saver Coded a lightweight program (600 KB), 'Battery Life Saver' to extend the life span of laptop batteries. Using a Laptop Battery continuously by overcharging above 90% or by below 15%, reduces its life span.   This light-weight .exe program, Battery Life Saver will alarm, on excess charging or discharging.   Set the desired Battery Limit Percentage using the slider, say 50% and allow the Battery Life Saver to give alarm. It automatically detects, charging and battery status. Screenshots DOWNLOAD Download the Python codes for this program, from this page.   Python code for Laptop Battery Life Saver     Author Dr. M Kanagasabapathy Asst. Professor, Department of Chemistry Rajus’ College, Madurai Kamaraj University Rajapalayam (Tamil Nadu) India 626117

### Google Sheet to check the consistent growth of a stock for 52 weeks Designed a Google sheet-based analysis to check, whether the growth of a stock is consistent or not in the past one year. It calculates and averages the return of every previous, 7 days' close price for the past 1 year, from yesterday’s date and closing price. So it's possible to check whether the growth is consistent for the past 52 weeks instead of conventional one-year return calculation, which is based on initial and final dates of a year. In simple, it estimates an average of weekly returns (for the consequent previous 52 weeks from yesterday) and compares it with conventional yearly return (%). Screenshot Link to Google sheet

### INVESTOCK – Simple Python computer programing code to fetch & back test NSE historical (15+ years) stock price data F et ch hist orical price data and back test between any two dates of NSE Stocks using this simple Python code and import them in .CSV file and predict the winning percentage. Step 1. Install NSEPY Open Command Prompt (in Windows 10) as Administrator. Then paste the following commands (shown in red ) one after another. C:\Python\python.exe -m pip install --upgrade pip Wait to upgrade... pip install nsepy Wait to upgrade... pip install nsepy –upgrade Wait to upgrade... Screenshot for installation in Windows 10 OS. Step 2. Fetching the price data Now open Python IDLE and paste the following code. Save it with a suitable filename, with an extension '.py'. Stock symbols and Date Enter the equity code as in NSE, India. Example: “TCS”) Enter starting and closing date digits, in the format, “yyyy,mm,dd” Example: “7-Aug-2021” is entered as: “2021,8,7") Change Symbol and starting as well as closing date in the required format. The data will be saved as .CSV file. Code Copy and past

### How to calculate Area under Curve & FWHM using the computer program Origin? Area under a curve can be estimated by integration method. (Check the references for more details.) Full width at half maximum (FWHM) for a curve is used in many scientific data analyses.  For instance, in X–ray diffraction (XRD) analysis of crystal data, it is used to find grain size.   It can be easily calculated using, quadratic equation. (Check the references for more details.) This tutorial shows how to use the computer program Origin to estimate both ' Area under a Curve ' as well as ' FWHM '. Check these eNotes for  references 1.  Full Width at Half Maximum (FWHM) & Quadratic equation 2. Introduction to Quadratic equation 3.  Area under curve by integration method

### JavaScript Codes: Math - Trigonometric Functions

Input : Sine JavaScript & HTML code for SINE function Input : Sine JavaScript - Trigonometric Functions Calculator Input:        (Values in degree) sin : cos : tan : csc : sec : cot : asin : acos : atan : sinh : cosh : tanh : csch : sech : coth : asinh: acosh: atanh:

### Electronic Circuit Simulator - Free tool to analyze electronic circuits Free electronic circuit simulator to study and analyze electronic circuits. It has a good user interface and has a sizable number of circuit components. Its very useful tool for educational purposes and to analyze basic circuits to complicated circuits. Download Links  Windows       Linux   Mac (If not downloaded, o pen the link in New tab and enter.)

### VESTA for Linux Mint (Debian file) Linux Mint is one of the best operating system with a good GUI, open-sourced and can be installed on old PCs also. And VESTA is a computer package to analyze crystal structures & geometry, X-ray diffraction simulation (XRD), and to investigate Miller indices {h k l} data for crystal systems,  space groups of crystalline materials etc.  It is a 3D visualization program for structural models, volumetric data such as electron/nuclear densities, and crystal morphologies. it also deals with multiple structural models, volumetric data, and crystal morphologies in the same window. But its Debian version for Linux Mint operating system is not available for direct download.  You can download the VESTA.deb for Linux Mint from here.

### Interpretation of open interest (OI) & price change of a stock Based on open interest & price change data of a stock, the price trend of the stock is correlated as: Price Open Interest Price trend Increase Increase Increase (More buyers & long build-up) Increase Decrease Increase (Short positions covering)  Decrease Increase Decrease (More short positions build-up)  Decrease Decrease Decrease ( Long unwinding Buyers become sellers)

### Butler–Volmer equation & Current density

At 298 K the exchange current density (i o ) of an electrode having a surface area of 5 cm 2 , used in an electrodeposition process is 0.79 mA cm –2 . Estimate the applied current through the electrode if the overpotential (η) is 5 mV.   Required formula derived from the Butler–Volmer equation is: i = (i o η F) / (R T) where, ‘i’ is the applied current density (mA cm –2 ) i o is exchange current density = 0.79 mA cm –2 η is overpotential = 5 mV F is Faraday = 96485 C mol –1 R is gas constant = 8.314 J K –1 mol –1 T is temperature (in K) = 298 K Current density = Current (mA) / Surface area (cm 2 ) Surface area = 5 cm 2   Substituting these values in the equation, value of the applied current density is: i = (0.79 mA cm –2 × 5 mV × 96485 C mol –1 ) / (8.314 J K –1 mol –1 × 298 K).   Since, Joule = Volt × Coulomb or J = V × C. So, i = (0.79 mA cm –2 × 5 mV × 96485 C mol –1 ) / (8.314 V C K –1 mol –1 × 298 K)   And, 1 V = 1000 mV

### Conversion of electrical units (Capacitance) into energy and power units

Symbols used in this notes are: F – Farad; C – Coulomb; V – Volt; A – Ampere; J –Joules; s – second; W – Watt; g – gram; h – hour   Correlation between electrical (capacitance) and energy and power units F = C/V W = A×V C = A×s J = W×s (Energy unit) F =(A×s)/ V So, F×(V^2) = A×s×V = W×s = J Or, F = (W×s) / V^2 = J / V^2 Note : Faraday's Constant is different from Farad. (Not confused, though both represented by symbol 'F'.) 1 Faraday = 96485 C 1 Faraday = (96485 C /3600 s) = 26.801 A·h   Capacitance is expressed in, F Energy is expressed in, Wh Power is expressed in, W   Specific Capacitance is expressed as: F/kg (or) F/g Specific Energy is expressed as: Wh/kg (or) Wh/g Specific Power is expressed as: W/kg (or) W/g   Assume a supercapacitor has a Specific Capacitance of 2000 F/g and discharges at a potential difference of 1 V in 900 s, then Specific Energy and Specific Power is related to its Specific Capacitance a