Charging and discharging device

The invention discloses a charging and discharging device, relates to a charging technology and aims at providing a charging and discharging device for charging and discharging battery jars with different voltages. The technical scheme for realizing the invention is characterized in that the charging and discharging device comprises a rectifier and is characterized in that a tap switch K3 is opposite to a secondary tap of a transformer; the other end of the tap switch K3 is connected with a power supply input end of a rectifying circuit; a positive electrode and a negative electrode of the output end of the rectifying circuit are respectively connected with a positive electrode and a negative electrode of the output end of the charging and discharging device; one end of a voltmeter U3 and one end of a capacitor C3 are respectively connected with the positive electrode of the rectifying circuit and the positive electrode of the charging and discharging device; the other end of the voltmeter U3 and the other en