SERIES 26 Pull to Turn Isolated Positions BCD or Gray Code Shaft & Panel Seal description 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”. DIMENSIONS in inches (and millimeters) Optical and Mechanical Encoders Switch Position *Dot indicates terminal tied to common. ORDERING INFORMATION SPECIFICATIONS Electrical Ratings 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 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 40oC for 240 hours (MIL-STD-202 Method 103, Test Condition A) OPTIONS Isolated Positions 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 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. 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. Grayhill, Inc. • 561 Hillgrove Avenue • LaGrange, Il