How the spark is produced in Electric Discharge Machining ?
A typical circuit used for supplying the power to an EDM machine is named as the relaxation circuit. The circuit consists of a DC power source, which charges the capacitor ‘C’ across a resistance ‘Rc’. Initially when the capacitor is in the uncharged condition, when the power supply is on with a voltage of Vo, a heavy current, ic, will flow in the circuit as shown to charge the capacitor. The relaxation circuit as explained above was used in the early EDM machines. They are limited to the low material removal rates for fine finish, which limits its application. This can be explained from the fact that the time spent on charging the capacitor is quite large during which time, no machining can actually take place. Thus the material removal rates are low.
How to Calculate Time Elapsed?
Time Elapsed calculator uses Time Elapsed for Voltage Discharge = -Resistance of Discharging Voltage*Capacitance of Voltage Discharge*ln(Discharge Voltage of EDM/Voltage at any Time in Voltage Discharge) to calculate the Time Elapsed for Voltage Discharge, The Time elapsed formula is defined as the time elapsed since the commencement of the task to provide sparking power to EDM electrode. Time Elapsed for Voltage Discharge is denoted by t symbol.
How to calculate Time Elapsed using this online calculator? To use this online calculator for Time Elapsed, enter Resistance of Discharging Voltage (Rdv), Capacitance of Voltage Discharge (C), Discharge Voltage of EDM (Vdis) & Voltage at any Time in Voltage Discharge (Vc) and hit the calculate button. Here is how the Time Elapsed calculation can be explained with given input values -> 12.20801 = -0.31*40*ln(0.76/2).