Function: The R Block compares an input signal with a set point reference and gives a control output signal proportional to the difference.

Application Notes: If the input signal matches the set point then the output will be 50% of the output span. If the input signal falls below the set point, the output will fall reaching 0% of output span for a 5% drop in the input signal from the set point. Conversely the output will reach 100% if the input signal climbs to 5% above the set point. The ±5% figures represent the proportional band and are adjustable on site to suit the control characteristics of the installation.

Power supply: mains powered

Function: Open or Closed-Loop servo controller, the output of which gives drive to electrical loads, in proportion to the difference between the Set-Point signal and the Feedback signal.

Application Notes: The S Block is designed for accurately positioning electrical actuators. The actuator servo motors can be DC or AC single, two or three phase of almost any HP rating, and can be used for positioning valves and dampers, etc. The SSRs that we offer are of a sealed construction with no moving parts and are particularly suited to applications requiring long life and high durability with contact-less switching. The control input is optically isolated from the zero voltage switching triac control circuit which minimises RFI. The SSR may be operated by TTL. The output circuit is Normally Open and will switch loads up to 240V AC at 10 Amps. Generally no derating is required for inductive or lamp loads due to the excellent surge capability. Ratings apply up to 40°C when mounted on a 1°C/W heatsink.

Power supply: mains powered

Function:
Controller - The C600 is a closed-loop servo controller in which the output is in proportion to the difference between the measured value and the set-point signal. The output signal is effectively varied by changing the mark/space ratio of the output pulses whose average frequency may be adjusted internally. The output can be in the form of volt free contacts, a volt free triac or push-pull power transistors which require an external DC power supply. Front panel adjustments include position balance at both ends of the control stage, dead band width and proportional band width. Switches may be supplied for manual override.

Comparator - The C600/1 compares an input signal with a set-point and energises either the "Raise" relay, if the input deviates from the dead band in the negative direction, or the "Lower" relay if the deviation is in the positive direction.

Mark Space Driver - The C600/2 is a single input instrument that provides an output mark space ratio proportional to the input signal. At 0% of the input span there will be no output. At 50% of the input span the output will be an equal mark space ratio and at 100% of the output span the output will be continuous. The pulse time constant is adjustable.

Power supply: mains or DC