| 摘要 |
PURPOSE:To simplify a circuit by selecting the entire voltage of a series circuit where plural voltage division resistors are connected in series, selecting an optional connecting point among connecting points of the voltage division resistors and leading a voltage from the connecting point so as to introduce the voltages of geometric series having a number corresponding to the product. CONSTITUTION:In order to generate a voltage represented in a geometric series represented in 2<a.n>, the 1st resistor RA and the 2nd resistor RB are connected in series with a reference voltage source and the 3rd resistor Rc is connected in parallel with the 2nd resistor RB. The resistance values of each resistor form a related equation. The 1st resistor RA is divided into n-set, the voltage of each voltage dividing point is led out via the 1st switching element group and a control circuit controlling the conduction of the 1st switching group in response to the input signal is provided and switching elements QB, QC are connected respectively in series with the 2nd resistor RB and the 3rd resistor RC. A voltage dividing voltage is led out by using a signal controlling the witching elements QB, QC and the output signal of the control circuit. |
