1、 Characteristics
PSL and PSQ actuators are products launched by PS Automation GmbH, a German manufacturer of actuators. The PS series electronic actuator can be used for adjusting and controlling the opening and closing of valves and dampers in pipelines. Its main features are as follows:
(1) The integrated structure design allows the position transmitter and servo amplifier to be directly installed inside the actuator as two independent components, receiving 4-20mA control signals and outputting 4-20mA or 1-5VDC valve position feedback signals. It has self diagnostic function and is very convenient to use and calibrate.
(2) Functional modular structure design, through the combination of different optional functions, achieves control from simple to complex, meeting different application requirements.
(3) The structure is simple, compact in size, lightweight, easy to install and maintain, and all mechanical parts are made by CNC machining with exquisite craftsmanship.
(4) The transmission adopts small backlash sealed gears, which have the characteristics of high efficiency, low noise, long service life, stability and reliability, and no need for refueling.
(5) It has multiple operating speeds to meet the requirements of various control systems, ensuring fast response and stability of the system.
(6) The PSL series is connected to the valve using a flexible coil spring, which can avoid the impact of the valve stem and output shaft being different from each other on the valve. The valve closing force can be pre-set to ensure reliable closing of the valve and prevent leakage.
(7) The PSQ series has torque switch protection to prevent damage to the valve stem due to excessive torque generated by the valve.
(8) The driving motor is a high-speed synchronous motor made of high-performance rare earth magnetic materials, which runs smoothly. It has the characteristics of small size, high torque, anti blocking, and high control accuracy.
(9) Segmented adjustment can be set, that is, the dual time proportional signal output by one regulator controls two actuators (4-12mA corresponds to the full open and full close of PSL1, 12-20mA corresponds to the full open and full close of PSL2).
(10) The valve position feedback component adopts a fully sealed high-precision multi turn potentiometer, which has the characteristics of small volume, high accuracy, small dead zone, and long service life.
(11) Adjustable stroke for easy connection with valves.
(12) All electrical components are made of world-renowned brand products, with reliable quality and long service life.
(13) The wiring of electrical components is rigorous and completely isolated from transmission components, which improves the reliability of the operation of the actuator.

2、 Product Structure
The wiring of the electrical components of the PS series actuator is rigorous and completely isolated from the transmission components, improving the reliability of the actuator operation. The transmission components adopt CNC machined small backlash sealed gear transmission, which has the characteristics of high efficiency, low noise, long service life, stability and reliability, and will not cause resonance of the actuator due to fluctuations in the process environment such as medium inlet force.
1. PSL linear actuator
The PSL linear actuator is mainly composed of isolated electrical control parts and gear transmission parts. As an intermediate component connecting two isolated parts, the motor outputs torque according to control requirements, which is transmitted to the trapezoidal screw through a multipole spur gear. The screw converts torque into thrust through rod threads. This rod thread can self lock and transmit linear travel to the valve stem through an adapter with the valve. The actuator shaft is equipped with a stop pin to prevent rotation, and the radial locking device of the shaft can serve as a position indicator. The locking device is connected to a connecting rod that runs synchronously with the output shaft. The displacement of the output shaft is converted into an electrical signal through a circuit board connected to the connecting rod, which is provided to the servo amplifier as a comparison signal and valve position feedback output. At the same time, the stroke of the actuator can also be limited by two main limit switches on the switch board, and the limit position can be adjusted by two mechanical limit blocks.
2. PSQ angular travel actuator
The PSQ angular stroke actuator is mainly composed of an isolated electrical control part and a gear transmission part, with the motor serving as the intermediate component connecting the two isolated parts. The motor torque is transmitted to the planetary gears through the main gear, and the main gear drives the planetary gears to drive the hollow gears. Hollow gears have three fewer teeth than secondary gears, so they can be driven by planetary gears. When a planetary gear rotates once, the hollow gear rotates three teeth, and the outer part of the planetary gear always meshes with a worm gear, which does not separate during operation. This design allows the motor to be manually controlled through the handwheel in case of faults or unexpected increases in valve torque.
The actuator has two threaded stop mechanisms and two limit switches to achieve electrical limit. The stroke range of each turn can be controlled by the position of the limit switch. The valve opening is indicated by a protruding display, and the unique torque switch can adjust the maximum torque from 50% to 100%, achieving torque protection to prevent valve stem damage caused by valve jamming.
3、 Product selection
The PS series electronic integrated electric actuator is small in size, light in weight, strong in function, and can be equipped with a servo amplifier. It is easy to operate and can be widely used for opening and adjusting valves and dampers in pipelines.
（1） PSL linear electric actuator
The PSL series linear electric actuator has a maximum stroke of 100mm and a maximum thrust of 25KN, making it suitable for valve switching and adjustment control in linear motion.

Main technical parameters of PSL linear electric actuator:

4、 Servo amplifier PSAP4B
The electronic proportional servo circuit supporting the electric actuator adopts SMT technology, which has the characteristics of small size and high reliability. This circuit will control the 4-20mA current signal of the electric actuator, compare it with the current position signal of the actuator, and control the opening or closing action of the actuator according to the deviation situation, so as to balance the position of the actuator with the input signal.
PSAP4B not only implements the action of the actuator with the input 4-20mA signal, but also provides a set of 4-20mA position signals isolated from the working power supply and input signal to the system.
PSAP4B can easily adjust the starting position and stroke of the actuator; Can easily switch between positive and negative effects; Set the actuator to fully open, fully closed, or hold state when the input signal fails.
1. Working principle
The position signal conversion circuit converts the variation of the 1000 ohm three wire sliding resistance signal reflecting the position of the actuator into 4-20mA. The control input and position signal are simultaneously sent to the deviation amplifier for comparison, and the comparison result controls the on/off of the solid-state switch, achieving on/off control of the actuator. Adjusting sensitivity according to control requirements can change tracking accuracy and eliminate oscillations that may occur due to mechanical inertia.
2. Technical parameters
Power supply: 220V 50Hz
Power consumption: 5VA
Switch capacity: 150VA (24V 50VA)
Input signal: 4-20mA
Input impedance: 150 Ω
Output signal: 4-20mA (active isolated output)
Load capacity: ≤ 350 Ω at 4-20mA
Insulation resistance: Main circuit - Control circuit: 100M Ω (500VDC)
Control circuit output circuit: 100M Ω (500VDC)
Output circuit one main circuit: 100M Ω (500VDC)
Repetition accuracy: ± 1%
Sensitivity: ± (0.5-5%) FS Lag: 50% Sensitivity
Environmental temperature: -20 ℃~+70 ℃ Storage temperature: -30 ℃~+50 ℃
3. Additional travel (2WE) and additional torque (2DE) switches
The additional travel (2WE) and additional torque (2DE) switches are paired with two additional switches, which can output two passive contact signals (220VAC 5A) when the actuator reaches the appropriate position or torque.
4. Single/Dual Valve Position Feedback Potentiometer (POT/POT2)
Output 1 group (POT) or 2 groups (POT2) of 0-1000 Ω resistance signals corresponding to the same valve position value, as the valve position feedback input signal of the servo amplifier or transferred to the instrument for valve position display.
4. Heating resistor (HR)
Installed inside the actuator to maintain a certain temperature, in order to avoid frost formation and damage to the electrical components of the actuator when used at low temperatures (below -20 ℃).
5. Independent position transmitter PSMF
When no built-in servo amplifier is required and only 4-20mA valve position signal needs to be output, it is selected.
6. Other optional application components