Ⅰ. Summary: water filter circuit board
 1.Application scope：≦400G water purifier
 2.Operating temperature：-20°C - +70°C
 3.Operating Humidity：5%-85%
Ⅱ. Performance Indicators:
 Power supply：DC24V
 Load current：3A
 Controls Power Consumption：＜ 5W
Screen size：70*30mm
 Mounting holes size：120/110*50/40/20mm
 PCB size：130*60mm
Ⅲ. Specific Function:
This circuit board has the function of testing TDS values
Ⅰ. Power :
 The computer board energized after 2 seconds to enter the operating  state. Buzzer chirping and machine automatically wash for 18s. Icon flashes indicate the respective operating state.
Ⅱ. Wash:  s=seconds
（1） Boot automatically washing for 18s
（2）Press the "Strong Wash Button" to automatically washing for 18s.
（3）Automatically washing for 18S every 6 hours.
（4）Automatically washing for 18S when water lack turns to source
（5）Automatically washing for 8S after water full (Cumulatively purify more than 60s, automatically washing for 8S after water full)
Ⅲ. Purify:
 When the switch detected a pressure lower than normal high pressure,the booster pump started to work,inlet valve opened and entered the purify process.
Ⅳ. Full:
 When the pressure reached a certain degree in pressure bucket,high-voltage switch turned off, the machines shut down,inlet valve closed.
Ⅴ. Lack:
When the low pressure switch detected the water pressure below the set value or the computer board detected low pressure switch off,the machines shut down,booster pump stopped,inlet valve closed, buzzer chirping for 10 seconds.
Ⅵ. Check:
  Continuously produced water for 6 hours(no water full), it means something wrong happened to the machine and entered the check process, buzzer chirping for 10 seconds.