How is the spark 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 during Charging?
Time Elapsed during Charging calculator uses Time Elapsed for EDM = -Time Constant for EDM*ln((Charging Current at any Time for EDM*Resistance of the Charging Circuit for EDM)/Voltage of Power Supply for EDM) to calculate the Time Elapsed for EDM, The Time elapsed during charging formula is defined as the time elapsed since the commencement of the task to provide sparking power to EDM electrode. Time Elapsed for EDM is denoted by tcc symbol.
How to calculate Time Elapsed during Charging using this online calculator? To use this online calculator for Time Elapsed during Charging, enter Time Constant for EDM (𝜏cc), Charging Current at any Time for EDM (ic), Resistance of the Charging Circuit for EDM (Rcc) & Voltage of Power Supply for EDM (Vcc) and hit the calculate button. Here is how the Time Elapsed during Charging calculation can be explained with given input values -> -18.232156 = -100*ln((6.1*0.18)/1.2).