Show when audio frequency transi transformer 0 burns out when an audio frequency transformer er la Is burned out there Is usually an open circuit in either the primary or secondary this may be tested by connecting it ft dry cell and a pair of phones in series with the thet Is connect oni one tip of the phones to the dry battery the primal y should first be tested as that winding Is usually the first to burn out this Is done by attaching a indre nl re from one terminal of the primary to the vacant terminal of the dry cell and the other end of tile the phone cord to one terminal of the primary if a click Is heard when tho the circuit Is completed there Is it a current flowing and the primary of the transformer Is id nil all right tills this should be rl heated in the same saine manner to test the secondary only the secondary terminals should be used instead of the primary it if the click Is heard beard the transformer la Is not burned out |