The Mayor and the directors of the several departments established by this Charter and/or ordinance shall constitute a Board of Control.  The Mayor shall be Chairman and shall appoint a secretary.  No contract involving an expenditure in excess of $2,500.00 shall be entered into without the prior approval of the Board of Control.  The Board shall have such further powers and perform such further duties as shall be prescribed by ordinance.  All expenditures by the City involving an amount of $2,500.00 or less shall not be made unless approved or ratified by the Board of Control.  (Amended 11-8-11.)