Graetz AG (formerly Ehrich & Graetz AG) was a German manufacturer of petrol lamps. In 1899 the company began to produce radio sets at its plant in Treptow, Berlin. The company lent its name to an electrical circuit called the diode bridge, which is better known as the full-wave bridge rectifier. A drawing of this circuit attributed to Graetz, dated 1897, appears in a paper by Chattopadhyay.