| 摘要 |
A temperature control circuit of an oven controlled crystal oscillator is a circuit in which a supply voltage is applied to a first terminal of a resistance R10, a first terminal of a resistance R11, and a first terminal of a heater resistance RH1, a second terminal of a thermistor TH1, a second terminal of a temperature sensing element, and a collector side of a transistor Q2 are connected to a common ground, a first terminal of a temperature sensing element ZZ is connected to an input terminal of an operational amplifier IC2, and a setting temperature in a thermostatic oven is controlled to gradually rise as an ambient operative temperature rises. |
| 主权项 |
1. A temperature control circuit of an oven controlled crystal oscillator, comprising:
an operational amplifier; and a PNP-type transistor, wherein
a supply voltage is applied to a first terminal of a first resistance, a first terminal of a second resistance, and a first terminal of a heater resistance,a second terminal of the first resistance is connected to a first terminal of a thermistor and a second terminal of the thermistor is connected to a ground,a second terminal of the second resistance is connected to a first terminal of a temperature sensing element and a second terminal of the temperature sensing element is connected to the ground,a connection point between the second terminal of the first resistance and the first terminal of the thermistor is connected to a first input terminal of the operational amplifier through a third resistance,a connection point between the second terminal of the second resistance and the first terminal of the temperature sensing element is connected to a second input terminal of the operational amplifier through a fourth resistance,an output of the operational amplifier is inputted to the first input terminal by feeding the output back through a fifth resistance and also inputted to a base of the transistor through a sixth resistance,a second terminal of the heater resistance is connected to an emitter of the transistor,a collector of the transistor is connected to the ground,each of the parts connected to the ground is connected to a ground-common wire, andthe temperature sensing element controls a setting temperature in a thermostatic oven to rise as an ambient operative temperature rises. |
