Temperatur and Pressure Controller

working in 24 V DC using Buck converter for high efficiency
Used 2-16 blue /white LCD Display with back light
micro controller based circuit.
4 relays (24V /10A each)used for Output control .
microcontroller outputs are opto isolated from relays for additional protection
sensors for temperature /pressure are 4-20 mA (1-5V) range type
Can be set desired Temperature /Pressure using UP DOWN Black push buttons in
the set mode then press the Green OK button the device goes to monitor mode.
The displayed control range is 0 -100 for 4-20 mA input.

when the temperature /pressure goes below the preset value then 24 volt

available at appropriate output this can used to switch a contactor on ,hence a

heater or compressor can be switch on.

when the temperature /pressure reach 5 point less than the preset value,24

volt available at its alarm out put to drive a buzzer and it only off when the

temperature and pressure goes10 point below the preset value

when the temperature or pressure reach the preset value the apropriate output goes OFF. This will stop the heater and compressor but alarm not OFF

Once the the temperature pressure out put goes OFF ,it will On again only the

temperature /pressure reach 10 point below the preset Value.

The alarm is to warn the increasing temperature pressure before it reach

presetted over temperataure/ pressure cut off .

When the device in monitor mode pressing the right black button enable the

setting mode

power button on the TOP make ON/OFF The unit

when the unit OFF all relay output goes N/O

when alarm is activated a bell symbol display showing which alarm is activated

when the heater or compressor relays are on numeric 1 is dispalayed in the left corner of display and when the relay off it indicate to 0

Comments

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