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 Resistance of Charging Circuit?
Resistance of Charging Circuit calculator uses Resistance of the Charging Circuit for EDM = (Voltage of Power Supply for EDM*exp(-Time Elapsed for EDM/Time Constant for EDM))/Charging Current at any Time for EDM to calculate the Resistance of the Charging Circuit for EDM, The Resistance of charging circuit formula is defined as the resistance offered by the charging circuit used to charge capacitor of EDM spark circuit. Resistance of the Charging Circuit for EDM is denoted by Rcc symbol.
How to calculate Resistance of Charging Circuit using this online calculator? To use this online calculator for Resistance of Charging Circuit, enter Voltage of Power Supply for EDM (Vcc), Time Elapsed for EDM (tcc), Time Constant for EDM (𝜏cc) & Charging Current at any Time for EDM (ic) and hit the calculate button. Here is how the Resistance of Charging Circuit calculation can be explained with given input values -> 0.137254 = (1.2*exp(-8.88/100))/6.1.