Shaft encoders use an LED light source that projects its light through transparent slots in an opaque rotating disc to a receiver on the other side of the disc, to provide precise information of its shaft rotation. When the shaft of the encoder is coupled to a machine, it will indicate position of the machine, whether the machine motion is rotary, or linear. Traditionally, the LED light source is visible Red, with an approximate wavelength of 660 nm.
While Photocraft has offered these legacy, Red LED-based encoders for years, they recently, introduced a new, improved design of encoder, using a Blue LED light source. The wavelength of the Blue LED is shorter, at 480 nm. The shorter wavelength of the Blue LED light source is more closely correlated to the small aperture of the transparent slots in the rotating disc, and results in less diffraction of the light after it passes through the disc on to the receiver. The shorter wavelength also facilitates smaller, shallow structures within the encoder. Coupled with the excellent temperature stability of Blue LED’s, Photocraft BlueCoder resolution, accuracy, and stability is unmatched.
Another advantage of the Photocraft BlueCoder Series is a slightly wider operating voltage. The majority of the legacy encoders with Red LED were rated 8-30 vdc, while the new BlueCoder Series is rated 4.5-30 vdc.
Photocraft offers their BlueCoder encoders in shafted, hollow-shaft, and wheeled types. The shafted types are the RB20, RBL, and RBS Series, hollow-shaft in the HSB20 Series, and wheeled encoders in the RB21, RB22, and RBH Series. Photocraft is owned by Tri-Tronics, an American manufacturer, in business since 1954. They manufacture their encoders in their Tampa facility.
Excel Automation and Eagle Sensors are an authorized Tri-Tronics Photocraft distributor, with offices in Cleveland, St. Louis & Kansas City. Call us if you have any additional questions about our quality products, or simply would like to place your order.