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 Resistance of Discharging Circuit from Capacitance?
Resistance of Discharging Circuit from Capacitance calculator uses Resistance of Discharging Voltage = -Time Elapsed for Voltage Discharge/(Capacitance of Voltage Discharge*ln(Discharge Voltage of EDM/Voltage at any Time in Voltage Discharge)) to calculate the Resistance of Discharging Voltage, The Resistance of discharging circuit from capacitance formula is defined as the sum of inductor resistance and resistance of the sparking load in the discharging circuit. Resistance of Discharging Voltage is denoted by Rdv symbol.
How to calculate Resistance of Discharging Circuit from Capacitance using this online calculator? To use this online calculator for Resistance of Discharging Circuit from Capacitance, enter Time Elapsed for Voltage Discharge (t), 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 Resistance of Discharging Circuit from Capacitance calculation can be explained with given input values -> 0.304718 = -12/(40*ln(0.76/2)).