Keywords: DS600, temperature control circuit diagram
Author: Li Erzi
The circuit schematic diagram of the temperature controller is shown in Figure 1, which is used by the temperature sensor DS600 produced by US Maxim as a temperature control device. It outputs different signal voltages at different ambient temperatures, and then enlarges with double op amp LM358. , An enlarged drive voltage control field effect tube, a fan. The basic principle is that the DS600 is a high sensitivity, analog output temperature sensor, its supply voltage range is 2.7V to 5.5V, which is set to 4.7V. Its temperature change and the output voltage are 6.45 mV / ° C, which is linear. The operating temperature range is -40 ° C ~ + 125 ° C, in the form of μSOP8 patch type. In its back (in the form of the package), there is a metal surface such as a radiator, with it to perceive the outer temperature, in order to make the warmth, the author is drawing the original graph and the PCB map, in order to draw a PCB map convenient Turning the DS600 over, the 1, 2, 3, 4 pins should be documented with 8, 7, 6, and 5 feet, so that the temperature of the temperature zone appears to face. The actual circuit DS600's 1 foot is VDD, and the circuit is 8 feet to vdd ... This point of view readers should pay attention to when reading. The signal voltage output from the 5 pin is fed from the voltage follower composed of one of the LM358. The signal voltage is output to the next level, and the action is mainly isolated. The signal voltage is transmitted to R7.
R7 picks up the signal voltage, which adjusts the startup voltage of the system fan. The high gain of the other op amp of the LM358 is inhaplified to enlarge the signal voltage to a large enough, passed through the partial pressure of R10, R11 to the gate control system fan of the field effect tube. The gain size of the high gain voltage amplifier is determined by R9 and R8. Adjusting R9 can adjust the temperature control range of the fan operation and the maximum speed. If the reader is in the imitation of the parameter sensation control range is not satisfactory, the resistance of R8 can be changed, the smaller the R8, the smaller the temperature control range, the higher the gain of the amplifier, but also moderately, gain over High, more than a certain range, the control effect will be counterproductive. The author's experience R8 should not be less than 10kΩ. It is worth mentioning that the author used a medium power triode instead of the field effect tube as the final type driving fan, but the actual application is not as good as the effect of the field effect, that is, the fan start - operation - the maximum The role of the speed is not significant.
All circuitors are made on a single layer of 45mm × 22mm, and the PCB diagram is shown in Figure 2, 3D see Figure 3. According to the PCB map, it is transferred to the board. The author is engraved with a knife, and of course the conditional readers can processed outside. The components are equipped in accordance with the parameters given in the figure. The regulator tube is 1 / 2W, the resistance is a 1 / 16W carbon film resistance, a patch package μSOP8 for LM358. The TO-220 package used by the effect of the field effect, the system fan is 12V, preferably the ball bearing.
After the board is processed, the DS600 two rows of pins will be made with a mouthpiece 1 to 4 feet or 5 to 8 feet, or 5 ~ 8 feet, respectively. Popular patch metader device, reload resistance and regulator tube. After welding, the V + is connected to the + 12V (yellow line) output of the computer ATX power supply. If there is a condition, the ATX power housing can be opened, and the V-5V (white line) is output, so that V + ~ V - There is 17V voltage. If the condition does not allow V- to the ground line (black line), at this time V 10 ~ V has a voltage of 12V, and the maximum speed of the fan is not necessarily ideal. After all, the circuit board is hung in the interior of the computer chassis, and the temperature is high, pay attention to insulation, do not touch other boards, etc., the system fan is in place in the back of the chassis, Plus the power to adjust. R7 and R9 can be adjusted according to the actual application. The ambient temperature at the time of the fan is adjusted by R7, and the ambient temperature range when the fan is rotated to the maximum speed is adjusted by R9. According to the case, the reader can pick a few system fans, mounted in different locations.
The actual application of the author, after booting, when the temperature of the chassis rises to 28 ° C, the system fan is started, the speed is slow, and when the temperature of the box continues to rise to about 32 ° C, the fan speed is significantly increased, and it is basically reached after a period of time. The increase in temperature in the chassis and the increase in system fan speed increase to the dynamic balance state of temperature in the chassis. When the temperature is around 30 ° C, the temperature can be substantially maintained at 32 ° C. This temperature also rises accordingly when room temperature is rising, but the fan noise is small, the rotation is smooth, and the design requirement is basically design.
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