Temperature detection, voltage-frequency conversion circuit

Relevant key device information applied in this article: LM35DZ LM131 9014, as shown in the figure, is a temperature detection, temperature-voltage conversion and voltage-frequency conversion circuit for remote temperature measurement. Connect this circuit to a radio transmission circuit to form a temperature control circuit. Test the remote control transmitting circuit. In the circuit, the integrated temperature sensor LM35DZ is used for temperature detection and temperature-voltage conversion. The temperature measurement range of this circuit is 0~100℃±O. 25℃, linear range 10mV/℃, operating voltage range 4~30V. The voltage-frequency converter uses a dedicated voltage-frequency conversion integrated circuit LM131. This series of products includes: LM131/131A, LM231/231A, LM331/331A. Any one of these models can be used in the circuit, and the parameters of the A suffix products are better than those of ordinary products. The temperature measurement circuit LM35 series products include: LM35A, LM35CA, LM35, LM35C, LM35D, etc. If LM35/35A is used as the temperature measurement circuit, the temperature measurement range is 2℃~150℃. At this time, the output frequency range of LM131 is 20 ~ 1500Hz. When it is necessary to measure 150℃, RP can be adjusted so that the output frequency is 1500Hz.