It is well know that in EDM, higher pulse energy
results in higher surface roughness compared to the
pulses with lower energy. The pulse energy is dependent
on current, voltage and pulse duration. RC type
generators are typically used for finishing operations,
where used capacitance mainly determines the pulseenergy. The smallest pulse energy achievable depends
on the stray capacitance of the circuit, also known as the
parasitic capacitance. Within this work, a state-of-art
power circuit was used for generating super-finishing
pulses solely using the stray capacitance. Although
measurement of the stray capacitance is difficult, based
on the calculated cable inductance, the obtained shortest
pulse durations (refer, fig. 2) suggest stray capacitance
of the used power circuit to be below 3nF