Encoders

An encoder is a component which reads off the position of a shaft with high precision.

The number of points of the encoder signifies its precision/resolution. An encoder with 1024 points can, therefore, indicate the position of the shaft with a precision of 360º/1024, which corresponds approximately to a third of a degree.

An incremental encoder is reset every time the power is turned on and off and the position of the shaft is indicated with regard to its starting position. An absolute encoder, on the other hand, always provides an absolute value from its zero position, regardless of its starting position.

Unlike incremental encoders, absolute encoders preserve their value even when the power is turned off. In the event of an emergency shutdown or a power cut, the encoder will indicate the position of the shaft at the time of the shutdown, even if the shaft has been moved after the shutdown time.

Incremental encoders

Shaft Encoders

RG Series, RJ Series, RS Series, RL Series, RBX Series, RC Series
Photocraft’s non-contact encoders (shaft encoders) with an optical shaft have a robust design and a flexible mechanical construction which make them ideally suited for industrial shop-floor environments.

Hollow Shaft Encoders

HS20 Series, HS25 Series, HRL Series, HRS Series
Output signals are generated by a shatter- and vibration-proof optical disk. The optical disk is mounted on the encoder shaft and has a special output pattern, which is read by one, two, or three optical sensors, depending on the number of output signals required. The sensors are temperature-compensated and rugged housing makes these sensors reliable for use in industrial environments.

The programmable incremental encoders include integrated micro-controllers and DIP switches, which can be accessed without opening the encoder. The micro-controllers are factory-programmed to generate different output signals depending on the settings of the DIP switches. The most common programme configurations allow the user to select the amount of pulses per revolution that should be generated, as well as the output signal. An encoder can have many different tasks, which simplifies the design of the system. Programmable encoders can generate up to three different output signals.

Signals that can be generated include:
• selectable single-pulse output,
• selectable 4-pulse output,
• fractional pulses per revolution, for example 2.5 ppr (parts per rotation),
• limited speed indicator,
• rotational direction indicator,
• anti-jitter,
• number of pulses per rotation (up to 3,600).

Wheeled Encoders

The RH encoder, also known as a Pulse Position Indicator), has wheels that are mounted directly on a conveyor belt. It is suitable for applications like material handling and sorting equipment, which uses bar codes or CCD systems. This type of encoder does not wear as much as an ordinary shaft encoder.

The RH encoder is equipped with 2 wheels (12’‘/30 cm) that are mounted directly on a conveyor belt. The two wheels make the device easy to install stably without the need for a special suspension mechanism.

The RH-1800/3600 encoder, which generates 1,800 and 3,600 pulses per revolution, is available for high resolution applications. This makes the encoder suitable even for high resolution applications such as printing and CCD scanner applications.
We can also provide accessories for the suspension of the encoder, such as when it is installed from below.