MODEL A 1-13/16” Diameter 10-Turn Wirewound 2 Precision Potentiometer ELECTRICAL Resistance Range, Ohms 10 to 500K Standard Resistance Tolerance < 100 Ohms = ±5%, ≥ 100 Ohms = ±3% Minimum Practical Resistance Tolerance ±1% Independent Linearity < 300 Ohms = ±0.50%, ≥ 300 Ohms = ±0.25% Minimum Practical Independent Linearity ±0.15%, ≤ 20 Ohms ±0.10%, < 100 Ohms ±0.075%, < 300 Ohms ±0.05%, ≥ 300 Ohms Power Rating, Watts 5.0 at 40°C derating to 0 at 85°C Input Voltage, Maximum 1,000Vdc not to exceed power rating Dielectric Strength 1,000V rms Insulation Resistance, Minimum 1,000 Megohms Noise, Maximum 500 Ohms: RT ≤ 2613.7 Ohms 250 Ohms: RT > 2613.7 Ohms Actual Electrical Travel 3600° + 4° – 0° Tap Tolerance ≤ 20 Ohms = ±3°, < 100 Ohms = ±2° < 300 Ohms = ±1.5°, ≥ 300 Ohms = ±1° End Voltage, Maximum 10 Ohms = 3%, 25 Ohms = 1.2% (% of input voltage) 50 Ohms = 0.6%, ≥100 Ohms = 0.25% This model available in a hybrid version – contact factory for details. ENVIRONMENTAL (MIL-R-12934) Operating Temperature Range Static: –65°C to +85°C Dynamic: –40°C to +85°C Temperature Cycling 5 cycles, –65°C to +85°C (5% ΔR) Shock, 6ms Sawtooth 100G’s (0.1ms discontinuity max.) Vibration 6 hours, 10 to 55 Hz (5% ΔRT, 0.1ms discontinuity max.) Moisture Resistance Ten 24 hour cycles (3% ΔR) High Temperature Exposure 1,000 hours at 85°C (5% ΔR) Rotational Load Life 2 mil. shaft rev. + 900 hrs. at rated wattage at 40°C (5% ΔR) Specifications subject to change without notice. 2-5 Model A MECHANICAL Total Mechanical Travel 3600° + 4° – 0° Number of Gangs, Maximum 3 Weight, Nominal (Single Gang) 4.4 oz. Static Stop Strength 550 oz.-in. Backlash, Maximum 1° Panel Nut Tightening Torque, Maximum 25 lb.-in. Shaft End Play, Maximum .005” Shaft Runout, T.I.R., Maximum .0005” Pilot Diameter Runout, T.I.R., Maximum .002” Lateral Runout, T.I.R., Maximum .003” Shaft Radial Play, Maximum .003” Start/Run Torque, Maximum (per gang) 3.0 oz.-in. STANDARD RESISTANCE VALUES, OHMS Theoretical Total Resolution Tempco Resistance (% Nominal) of Wire 10 0.082 +800 ppm/°C * 25 0.040 +800 ppm/°C * 50 0.031 +800 ppm/°C * 100 0.040 ±20 ppm/°C 200 0.031 ±20 ppm/°C 500 0.024 ±20 ppm/°C 1K 0.021 ±20 ppm/°C 2K 0.016 ±20 ppm/°C 5K 0.014 +130 ppm/°C * 10K 0.011 +130 ppm/°C * 20K 0.009 +130 ppm/°C * 50K 0.007 +130 ppm/°C * 100K 0.006 ±20 ppm/°C 200K 0.005 ±20 ppm/°C 300K 0.005 ±20 ppm/°C 500K 0.005 ±20 ppm/°C * Lower tempco available as a special model. 2-6 Model A OUTLINE DIMENSIONS (Inch/mm) Dim. “L” Dim. “M” Dim. “RS” No. of Gangs 2.016 2.062±.031 2.875±.031 1 Max. 51.21 52.38±0.79 73.03±0.79 4.243 4.205±.031 5.016±.031 Max. 2 107.78 106.81±0.79 127.41±.0.79 2 6.143 6.100±.031 6.906+.031 Max. 3 156.04 154.94±0.79 175.42±0.79 Mounting Surface RS .062±.016 1.58±0.41 M .812±.031 20.6±0.79 L +.000 1.250 .406 -.002 R Max. Slider Dia. CW 31.75 +0.000 10.312 CCW -0.051 +.0000 .2497 -.0003 Dia. +0.0000 1.812±.016 6.3424 -0.0076 46.03±0.41 .562±.016 Dia. 14.3±0.41 .016 Chamfer Max. x 45° 0.41 .062±.016 3/8 - 32 UNEF Thread .312±.025 1.58±0.41 2 & 3 Gang Outline 7.93±0.64 Locating Lug .312±.016 7.93±0.41 .125±.005/3.175±0.127 Dia. Positioned as Shown ±5° METRIC CONVERSIONS 1 in. 25.4mm 1 oz.-in. 0,007 N-m 1 oz. 28.4 gm 1 lb.-in. 0,113 N-m 2-7 Model A SPECIAL FEATURE CODES Center Tap CT Linearity Tape LT Rear Shaft Extension RS Flatted Shaft FS Slotted Shaft SS Shaft Lock SL Color Coded CC Additional Gangs 2G or 3G ORDERING INFORMATION A R 10K T2 L .25 XX Optional Special Model Series Feature Code Resistance Prefix Linearity Resistance Value Optional Non-Standard Tolerance MATCHING TURNS COUNTING DIALS 2606, 2607, 2626, 2627, 2646, 2647, 2126, 2606S, 2607S, 2646S, 2647S, RB NOTES CIRCUIT DIAGRAM Metric equivalents, based on 1 inch = 25.4mm are rounded to the same number of significant figures as in the original English units INCH and are provided for general information only. mm (S) Tolerances unless otherwise specified: Linear = ± .01 inches (CCW) (CW) (.25mm) Angular = ± 2 degrees 2-8 Model A