The ordinance authorizing the refunding bonds shall prescribe all details thereof and shall provide for the levy and collection of a direct annual tax upon all the taxable property within the county sufficient to pay the principal thereof and interest thereon as it matures. This tax shall be in addition to and exclusive of the maximum of all other taxes authorized to be levied by the county. Tax limitations applicable to the county provided by statutes of this State shall not apply to taxes levied for payment of these refunding bonds. However, taxes provided to be levied for payment of refunding bonds of any county shall not be in excess of the constitutional limitation of 75? per $100 valuation unless that excess is authorized by a vote of the people of the county.
     A certified copy of the bond ordinance shall be filed with the county clerk of the county and shall constitute the authority for the extension and collection of refunding bond and interest taxes as required by the constitution.