TC02 Temperature Measurement Circuit ----- Temperature Detection

Keywords: Temperature Measurement Circuit, Electronic Temperature Meter Circuit Temperature measurement circuit The temperature measurement circuit is shown as shown. In the figure, S1 is a point / bar display mode conversion switch. When the power supply voltage Vcc>8V, the LED1 to LED 10 may not be used in series to limit stream resistance. The current at the LED is set by the 4, 6 foot external resistor. It is assumed that the 4, 6 foot external electric resistance is 1.2kΩ (including resistance between the R1 and BP1 central head to 4 pins), and the total resistance of the LM3914 internal divider 10kΩ, The equivalent resistance between 4 and 6th is about 10.7kΩ, and the 1.25V reference voltage is supplied to the voltage divider circuit is 1.25 V / 1.07KΩ ≈ 1.2mA. The LED illuminating current is 10 times that of this current, that is, about 12 mA. This is the advantage of the floating of the resistance divider. The reference voltage source between 7 and 8 pieces is also floating, 6-pin can be used with an internal 1.25V reference voltage in 7 foots, and 6 feet can also be external to other reference voltages. If RP1 is not used, R1 is connected to 4 foots, and the voltage divider vertex voltage is 1.25V. Due to LM3914 is a linear partial pressure, the adjacent voltage comparator is insertion of 0.125V. When the 5 foot input is zero, the 10th-level voltage comparator is locked, all LEDs do not illuminate; when the 5-pin inputs a slow rising signal voltage, if it works in a bar display mode, the voltage is 0.125V. One LED luminous, 10 LEDs all over the 1.25V. If you work in a moving point display, the input voltage is changed separately for each increase of 0.125V. The potential of the low end 4 pin can be changed using BP1, so the range of range of display temperature can be changed. In actual use, change the RP1 resistance to adjust the display range, and adjust the RP1, the temperature display range can be fine. Component Selection: TC02 is the voltage output integrated temperature sensor produced by Telcom, which is linear with the temperature of the output voltage and Celsius. Its main characteristic parameters are: working voltage 3V ~ 12V; typical quiescent current 40mA, maximum 60mA; output sensitivity is 100mv / Oc; nonlinear error is ± 0.8 ° C; the measurement accuracy is typically ± 0.5 ° C; the temperature range is -40 ° C ~ 125 ° C.

Our other product:

Professional lightning protection system for Tower	Professional FM Radio Station Equipment Package	FMUSER FU-1000C 1000W FM Transmitter With USB Audio Input Interface
FMUSER 200W FM Radio Broadcasting Package	Hotel IPTV Solution	FMUSER FSN-1000T V5.0 1KW FM Radio Broadcast Transmitter