We present the study of DC currents of an open dot generated from two time dependent electric fields in the absence of external bias. Two electrical setups were applied. In one configuration, two fast oscillating voltages were applied on two side gates; in the other, one of the oscillating biases was directly applied to the source lead. The DC current as a function of frequency, coupling strength, and magnetic field was investigated. The current is sinusoidally dependent with the phase shift and bilinearly dependent with the excitation voltage for both configurations. However, the current as a function of frequency, coupling strength, and magnetic fields behaves differently in these two setups. The results indicate that the currents generated in different setups originate from different mechanisms, and moreover, not from any classical circuitry effect.