Abstract: The present invention provides an oscillation circuit which enables a further decrease of power consumption. The oscillation circuit comprises a piezoelectric oscillator, such as a quartz oscillator, for generating voltage that oscillates at a natural frequency, an inverter for amplifying this oscillation voltage, a Schmitt trigger circuit for shaping the waveform of the output of the inverter and outputting oscillation output signals, and a constant current source which is connected to a power supply line from a battery and supplies current to the power supply of the inverter and the Schmitt trigger circuit.

Abstract: The present invention provides an oscillation circuit which enables a further decrease of power consumption. The oscillation circuit comprises a piezoelectric oscillator, such as a quartz oscillator, for generating voltage that oscillates at a natural frequency, an inverter for amplifying this oscillation voltage, a Schmitt trigger circuit for shaping the waveform of the output of the inverter and outputting oscillation output signals, and a constant current source which is connected to a power supply line from a battery and supplies current to the power supply of the inverter and the Schmitt trigger circuit.

Abstract: A recording and reproducing apparatus of the present invention has a magnetic head used for both recording and reproduction. To perform the changeover between recording and reproduction in a short period of time, a first recording amplifier for supplying a recording signal is provided at one end of the magnetic head, a second recording amplifier for supplying a recording signal of a phase opposite to that of the recording signal supplied to the one end of the magnetic head is provided at the other end of the magnetic head, and a reproduction input amplifier connected to the both ends of the magnetic head is provided. The same bias voltages are supplied through first and second resistors connected to the both ends of the magnetic head.

Abstract: A constant voltage circuit is to stabilize a constant voltage output with respect to a source voltage and produce the constant voltage output at a lower level of the source voltage. The constant voltage circuit is arranged to generate an output of constant voltage (constant voltage Vreg) by using a band-gap circuit (2), and comprises an error detecting circuit (4) for detecting an error voltage between the constant voltage generated by the band-gap circuit and a setting value, an output circuit (6) for receiving a current indicative of the error voltage from the error detecting circuit, generating a current depending on the received current, and feeding the generated current back to the band-gap circuit, and an initiating circuit (8) for supplying an initiation current to the band-gap circuit at the time of raising a source voltage.