Loss In Weight Controller
Loss in weight controller for screw feeding system :
This is a microcontroller based unit. It will measure rate of discharge of material from feeder and generate control output signal proportional to it.
- 1. Input :
- Load cell: 4-wire, excitation: 5VDC
- 2. Outputs :
- Control Output for feeder speed control: 1 to 5VDC/4-20 mA
- Control relay for refilling: Potential free contact
- Alarm Relay output: Potential free contact
- 3. Operating Voltage : 110-230VAC
Parameters to be set :
- Desired Rate of loss in weight (set point)
- Calibration for load cell input
- Control set points for refilling: Low level & High level
- Alarm conditions
- a. feeding error delay
- b. control action error (band of set and actual value)
- Appropriate Settings for control output
- Integrating total for feeding
- Feeder operating mode : Volumetric or Gravimetric
Functional description :
- The unit monitors actual weight & rate of discharge from the feeder
- Generates control signal based on desired set value of feeding rate and rate of
- loss in weight
- Monitors weight of hopper to take decision for refilling.
- If actual weight falls below low set weight, switch on relay to refill.
- When actual weight is equal to high set weight, switch off relay to stop feeding.
- During refilling operation, control output of feeding is maintained at last value.
- Once refilling is complete, control algorithm is activated again.
Other features of proposed controller :
- Display : 128 x 64 Graphics LCD with back light
- Keypad : 24 Keys, Membrane Keys
- Enclosure : Panel mount, metallic, General purpose
- Dimension : Outer: 133.5 (H) x 278 (W) x 160 (D) mm