| 摘要 |
PURPOSE:To make it possible to adjust the frequency without opening a thermostat, by using a varactor diode as the capacitor for frequency adjustment of a quartz oscillator. CONSTITUTION:Varactor diode 4 is connected in series to quartz oscillator XL, and both ends of diode 4 are connected to variable resistors RV1 and RV2 through resistances R1 and R2. Resistors RV1 and RV2 are connected in series, and their both ends are connected to the earth and reference power source VB, and resistor RV1 is a high resistance and is used for frequency absolute valve, and resistor RV2 is a low resistance and is used for correction of change dependent upon time elapse. Oscillating circuit 1, oscillator XL, and diode 4 are stored in a thermostat. |
