Control and regulation technology

Batch control with preselection pulse counter
The desired number of pump strokes per batch is set on an electronic preselection counter. When a start pulse is received, the pumping process begins. For each pump stroke, one stroke is subtracted from the preselection counter via the stroke frequency sensor on the pump. Once the preset value has been reached, the pump switches off automatically and the next batch can be started.

Controllable dosingpump (Cseries) (pulse signals)/proportional dosing via pulse signals
Proportional dosing with the dosing pump of the C series is dependent on the pulses of a contact water meter.
The electronics integrated in the pump convert the pulses into dosing strokes, with the option of pulse division or multiplication.

Controllable dosing pump (C series) (analogue signals)/proportional dosing via analogue signals
Proportional dosing with the dosing pump of the C series takes place depending on an analogue input signal 0/4...20 mA from a flow meter.
The electronics integrated in the pump convert the analogue signal proportionally into a corresponding stroke frequency.

Proportional control with frequency inverter operation: Varipuls/ VARIPULS (analogue signals)
A frequency inverter in the controller converts the 0/4...20 mA input signal directly into a proportional output frequency, which is applied to the pump's three-phase AC drive motor. Changes in the frequency cause a change in the motor speed in the same direction and thus the pump stroke rate. The flow rate of the pump is therefore controlled via the stroke frequency at a constant stroke length.

Proportional control with electric actuator: Variprop/VARIPROP (analogue signals)
An electronic positioner within the control system compares the reference variable with the position of the servomotor, which is reported by the position potentiometer. If there is a deviation, the actuator and thus the flow rate of the pump is readjusted via the stroke length until the reference variable and the assigned dosing quantity match.

Proportional pulse length controller
The pulse length controller is a switching controller in which the output variable is only available as the switching state "ON" or "OFF". The ratio of switch-on time to switch-off time and thus also of running time to pause time of the dosing pump changes proportionally to the control deviation. As the dosing pump is only switched on and off, a standard pump without a stroke actuator and without a controllable drive motor can be used.

Three-point steppingcontroller
Continuous dosing and flow rate adjustment is required for controlled systems with higher control quality.
The three-point stepping controller, which controls a stroke actuator of the dosing pump, fulfils this requirement as far as possible. The dosing pump runs continuously. In the event of a control deviation, the controller gradually sends "open" or "close" pulses to the actuator until the setpoint and actual values match.

Continuouscontroller
The continuous controller can also be used for control systems with high control quality.
Its output is an analogue signal that can continuously assume all intermediate values between 0 and 100 %, depending on the control deviation. The output of the continuous controller is fed directly to a frequency converter, which continuously adjusts the flow rate of the downstream dosing pump by adjusting the speed of the drive motor until the control deviation is zero.

Proportional pulse frequency controller
The pulse frequency controller is a controller in which the output variable is only available as a pulse signal.
The frequency of this pulse signal changes depending on the control deviation. A dosing pump from the C series can be used with this controller. The electronics integrated in the pump convert the pulse signal into dosing strokes.