| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable frequency oscillation circuit which is prevented from oscillating at an unwanted frequency by narrowly setting the frequency range that can control power conversion and a piezoelectric inverter. SOLUTION: A variable frequency oscillation circuit is composed of a current setting circuit 1, a constant-current circuit 2 the current value of which can be set by means of the circuit 1, and an oscillation circuit 3. The oscillation circuit 3 has a capacitor C1 connected to the output of the constant-current circuit 2 and a switch SW, which switches the voltage of the capacitor C1 to '0', when the voltage of the capacitor C1 reaches a specific value. The current setting circuit 1 is constituted by connecting a serial circuit of a transistor T1 and a first resistor R1 in parallel with a second resistor R2. The oscillation circuit 3, in addition, is provided with a first comparator 4, which compares the voltage of the capacitor C1 with a reference value and a second comparator 5, which transforms an oscillated triangular wave into a rectangular wave. |
