| 摘要 |
PURPOSE:To reduce the leakage of signals and to simplify the peripheral circuits of a coil to facilitate quite easy conversion of a data writing/reading circuit into an IC, by providing a switch circuit to select the energization to a coil which performs the data writing/reading jobs. CONSTITUTION:In a read mode the W and R outputs of a control circuit 11 are switched to a low level and a high level respectively by the control signal Cs. Then transistors (TR)Q41 and Q42 are turned on and off respectively and amplifiers 4a and 4b are inactive. While the output of an OR circuit 12 is set at a low level and therefore both TRs Q21 and Q22 are turned off. The power is supplied to a reading circuit 31 as a whole, and the signals read out of coils L1 and L2 are amplified. Thus an output signal R0 is obtained. A diode D is connected in series to both coils L1 and L2 and at the same time preamplifiers A1 and A2 are provided independently to the coils L1 and L2 respectively. Thus data can be read without using a complicated switch circuit. Furthermore the leakage of signals is reduced between both coils L1 and L2, and the constitution of this data writing/reading circuit is simplified for easy conversion into an IC. |
