Works pulse encoder
Pulse encoder is an optical position detecting element, the code disc directly mounted on the rotary shaft of the motor, and the rotational angle position of the measured shaft speed variation, its output signal is an electrical pulse. It is a common angular displacement sensor. Also can be used for speed detection means.
Advantage of the pulse encoder is free of friction and wear, driving torque is small, fast response. Pulse encoder disadvantage is poor anti-pollution, easily damaged.
Classification and structure of the pulse encoder
Divided photoelectric pulse encoder, and an electromagnetic induction contactless three. Photoelectric accuracy and reliability superior to the other two, so only a photoelectric pulse encoder on CNC machine tools.
Pulse encoder structure: a disc on the circumference of the engraved lined at equal intervals, into transparent and opaque portions, called circular grating. Circular grating rotates together with the working shaft. Opposite the circular grating, disposed parallel to a sheet fixed sector, called index grating, formed with the above two slits shifted by 1/4 pitch (resolution into the slit). In addition, there is a slot zero (one pulse per revolution). Head or a pulse generator connected to the servo motor by the cross bond.
Works pulse encoder
When the work is rotated together with the shaft angle encoder, the light through the lined portions of the two gratings forming light and dark stripes. Photovoltaic element receives light signals of light and dark, and converted into electric signals of alternating. The electrical signal is approximately sinusoidal current signal groups A and B, shown in Figure 4-17. A and B signals out of phase 90 °, amplified and shaped into a square wave. Signals through two gratings, there is a "pulses per revolution", referred to as Z-phase pulse, which also come through the above process. Z pulse for generating a reference point on the machine. Later pulse is supplied to a counter, according to the number and frequency of the pulses can be measured angle and the rotational speed of the working shaft. The resolution depends on multiple segments of circular grating lines and the measured number of turns.
Application of pulse encoder
Pulse encoder as the position detecting means on the CNC machine tools, a detection signal is fed back to the numerical control system. Fed back to the numerical control system in two ways: First, the required adaptation band down counting down counter counting pulses forming the pulse and counts down; the second is adapted to count with a count control requirements and counter, and the counting direction control signal form the pulse .
Many people do not understand how the encoder pulses are calculated, now I give you answer it.
Specifications are each encoder, has marked the resolution is.
Line units / turn;
Suppose a 1024 line / circle, then it means that for each revolution of the encoder, the pulse will be sent 1024 1024 A-phase and B-phase.
Then you look at your pulse receiver is how to calculate the number of pulses, if a frequency is (that is, a rising edge received complete phase A rising pulse and a B-phase pulses, a pulse count), then it is 1024 pulses received; if the multiplier is 4 (rising and falling of each of the a-phase and B-phase pulses are counted one pulse, one pair AB phase signal, the receiver 4 on the meter), then it is received 4096 pulses.
On each pulse encoder ABZ in the end what does it mean, and how to use?
A / B / Z is a three pulse output of the encoder,
A and B are generally two consecutive cycles differ by .25 pulse output, the rotational direction can be known by analyzing the phases of two pulses can be known by the speed of rotation frequency,
Z revolution encoder pulse occurs before a pulse encoder which is above a fixed reference point a, by its turn art will know how many laps,
Therefore, according to A / B / Z three pulse condition can analyze the state of the encoder position, i.e., speed, angle, orientation, and rotating a plurality of turns, it is desirable to understand
In selecting rotary encoder, they can find a suitable rotary encoder in terms of performance, cost, service life, and other formal channels, Shanghai opened to focus on electronic encoder industry for 12 years, providing customers with the most abundant and more is selected from the following products: incremental rotary encoders, magnetic & photoelectric type incremental encoder & absolute encoder, hollow sleeve of formula & solid shaft, general industrial & special riot formula, ordinary stainless steel shell & housing, & glass code-metal code wheel, the bearing of formula & carrying no bearing type, oversized & mini compact type, light duty & heavy duty, high temperature & ordinary temperature type, single-coder & bis encoder , modular assembly ...... imported brands, domestic prices are welcome.