Mechanical Encoders Series 26 Pull to Turn Description Isolated Positions BCD or Gray Code Shaft & Panel Seal DIMENSIONS An isolated position is one that cannot be reached by normal rotation. This version of the Series 26 mechanical encoder requires that the operator Pull-To-Turn in order to reach the isolated position. To rotate out of the isolated position, the operator must Pull-to-Turn again. Use isolated positions to protect a switch position from indiscriminate rotation. This feature is typically used for positions such as “calibrate”, “off” and/or “stand-by”. in inches (and millimeters) Grayhill part number and date code marked on label. Customer part number marked on request. Unless specified otherwise, all tolerances are ± .015 ( 0,38) Rated: 25,000 cycles with logic compatible loads. Make and break 200 mA. Contact Resistance: 500 milliohms maximum (less than 100 milliohms initially) Insulation Resistance: 1000 megohms minimum (10,000 megohms initially) Dielectric Strength: 250 Vac minimum The Grayhill system for isolating positions lets you choose the positions to be isolated. Grayhill inserts isolation posts next to the positions to be isolated. Consider a continuous rotation switch with a 22.5° angle of throw. The terminals are listed here from 1 through 16 with a space between each to indicate where isolation posts might be inserted. 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 To isolate position 1 and position 2 from all other positions and from each other, indicate isolation posts as shown here: 16P1P2P3 4 5 6 7 8 9 10 11 12 13 14 15 16 To isolate just position 1, describe like this: 16P1P2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 To isolate positions 1 and 2 from all other positions, but not from each other, do this: 16P1 2P3 4 5 6 7 8 9 10 11 12 13 14 15 16 Materials and Finishes Panel Seal: Silicone Rubber Shaft Seal: Fluorosilicone Mounting Nut: Brass, tin/zinc-plated Lockwasher: Steel, tin/zinc-plated Detent Balls: Carbon steel, nickel-plated Detent Spring: Pretinned music wire Detent Rotor: Thermoplastic Shaft, Stop Arm and Pins: Stainless steel Bushing: Zamak 3 zinc alloy, tin plate Switch Base: Diallyl phthalate Printed Circuit Board: NEMA Grade FR-4 Terminals: Brass, gold over nickel plate Contacts: Copper alloy, gold over nickel Additional Characteristics Shaft Vertical Travel: .050 +/- .010 Pull Force Required: 1.75 +/- .75 lbs. Rotational Torque: 7 to 13oz-in Vibration Resistance: 10 to 55 Hz at 0.060" double amplitude; no damage and no contact openings per MIL-STD-202, Method 201A Shock Resistance: Passes medium requirement per MIL-DTL-3786 Stop Strength: 5 in-lbs minimum Mounting Strength: 15 in-lbs max Relative Humidity: 90-95% at 40 oC for 240 hours (MIL-STD-202 Method 103, Test Condition A) Isolated Positions Fixed Stop Switches The switch may have continuous rotation, or specified to limit the rotation. When a 1-pole switch has less than the maximum number of positions, consider also the stop system. Following is the arrangement for a 6 position switch with the position 1 isolated. STOP 1P2 3 4 5 6 STOP The word “STOP” indicates the conventional switch stops, which limit rotation to positions 1 through 6. To isolate position 1 we insert only one isolation post–between terminals 1 and 2. The stop system already prevents rotation beyond terminal 1. Grayhill, Inc. • 561 Hillgrove Avenue • LaGrange, Illinois CODE AND TRUTH TABLE Code Position Options Electrical Ratings Switch Position Optical and Mechanical Encoders SPECIFICATIONS 1 2 3 4 5 6 7 8 9 10 11 0 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 11 12 13 14 15 BCD Output* 1 2 4 8 Gray Output* 1 2 4 8 *Dot indicates terminal tied to common. ORDERING INFORMATION Due to the vast number of possible configurations of isolated positions and stop arrangements, each Series 26 Pull-to-Turn Mechanical Encoder will be assigned a unique part number. For example, part 26YY50202 is a 16 position gray code switch with positions 1 and 16 isolated and a STOP at each extreme. Contact Grayhill or an authorized representative to create a part number and obtain pricing. 60525-5997 • USA • Phone: 708-354-1040 • Fax: 708-354-2820 • www.grayhill.com