Development of temperature controller scheme

Development of temperature controller scheme

1、 Function description

1. Product Overview

This product is a two-way water temperature controller with three working modes (standby mode, normal working mode and alarm mode), including two-way temperature acquisition sensors, two-way 5000 Watt heating control relay output, and a control panel (including four control keys, two-way and three groups of LED display, displaying the current temperature, on temperature and off temperature).

15353587063055.png

Under normal working conditions, the thermostat is powered on (~ 220V), MCU starts to work, the thermostat is in standby mode, the relay closes the output, and the current temperature display part displays the current water temperature. When the user presses the "switch" button, the thermostat enters the normal working mode, and the "opening temperature" nixie tube displays the set opening temperature (the default opening temperature is 28 ° C and the closing temperature is 32 ° C). When the temperature is lower than 28 ° C, the thermostat relay closes, the heating rod is powered on to heat, the water circulation motor starts to operate, and the corresponding "temperature rise" LED light is on (or 0.5s flashing). When the temperature reaches the set "off temperature", the thermostat relay will be closed, the heating rod will be powered off to stop heating, the water circulation motor will be shut down and the corresponding "cooling" led will be on (or 0.5s flashing). Repeat the operation to ensure that the water temperature is always controlled within the set range.

15353587492807.png

When in standby mode, the user presses the "setting" button, and the thermostat enters the setting mode. At this time, the first group of "on temperature" led nixie tube starts to flash. At this time, the user can press the "+" and "-" buttons on the board below to adjust (set) the "on temperature" of the first group. After the user has adjusted it or saved the default, the user presses "setting" again Button, the system immediately saves the "opening temperature" of the first group, the "opening temperature" nixie tube of the first group returns to the normal display, and the "opening temperature" nixie tube of the second group starts to flash. The user presses the "+" and "-" buttons on the lower board to adjust (setting, temperature setting range - 5 ° C ~ 98 ° C) the "opening temperature" of the second group , and so on until the four temperature settings are completed.

15353587748888.png

15353587856783.png

Anhydrous protection

When the sensor detects no water, the corresponding "current temperature" nixie tube flashes for 0.5s, displays E2 error code, and the corresponding output is closed until it returns to normal.

Leakage protection

When the sensor detects leakage, the corresponding "current temperature" nixie tube flashes for 0.5s and displays E3 error code, so the output is closed until it returns to normal.

Alarm mode

When the controller does not detect the temperature sensor and / or the temperature sensor is abnormal, the relay is turned off, the heater is turned off for heating, the corresponding "current temperature" nixie tube flashes "E1" for 0.5s, the error code, and the buzzer makes a sound of "drop" for 0.5s. When the water temperature reaches 34 ° C, the corresponding "current temperature" The nixie tube flashes for 0.5s to display the current temperature, and the buzzer emits a "drop drop" sound for 0.5s.

For the "no water alarm" and "electric leakage alarm" functions, the current controller provided by the customer has not found the corresponding sensor. If necessary, the design can be modified and added.

Power down mode

When the equipment is powered down in the normal working mode, control and save the current setting parameters. After power on again, the controller enters the standby mode. After the user presses the "switch" key, the thermostat starts to work (set the temperature as the data saved after the last power off).

Special note

Two groups of wiring terminals for heating and water recycling are required by customers to be led out by wires, the sensor interface is changed into easier pluggable terminals, and two groups of water shortage and leakage detection sensors are added.