The invention discloses a novel mechanical
control circuit and mode of a frequency converter, and aims to solve the problem that a frequency converter in the prior art cannot achieve the mechanical
control function by detecting the
voltage of a direct-current
bus. The novel mechanical
control circuit comprises a power supply module and a compressor module, wherein the power supply module is connected with the compressor module to supply power to the compressor module, the power supply module comprises an external alternating-current power supply and a
temperature control switch used for controlling the
voltage of a direct-current
bus, and the compressor module comprises a whole filter circuit, a
switching power supply
chip, a
voltage sampling circuit, a main core, a driving and inverting circuit, a current sampling circuit, a charging circuit, a battery and temperature sampling circuit and a power supply module. According to the invention, an
alternating current phase line is preventedfrom being additionally led out to serve as a
control signal, a
direct current bus voltage is converted into a high-low level
signal which can be recognized by a
single chip microcomputer through a series of voltage division and filtering, and a main core calculates the corresponding rotating speed according to the duty ratio of the
signal and controls a compressor with the corresponding rotatingspeed as reference, so that the cost is reduced; and the problem of over-high cost caused by additionally arranging a battery and a charging circuit is solved.