Features Non-standard features and 7/8 (22 mm) diameter single-turn specifications available conductive plastic Bushing mount Excellent resolution High rotational life ball bearing shaft support 6638 - Precision Potentiometer 1 Electrical Characteristics Product Dimensions Standard Resistance Range....................................................................................1 K to 100 K ohms Total Resistance Tolerance .........................................................................................................10 % 6638 Independent Linearity ...................................................................................................................1 % 7/8 (22 mm) DIA. 2 Effective Electrical Angle .......................................................................................................340 3 5.08 End Voltage .................................................................................................................0.5 % maximum R CW (.20) Output Smoothness ....................................................................................................0.1 % maximum Dielectric Withstanding Voltage (MIL-STD-202, Method 301) 3 1 Sea Level .............................................................................................................750 VAC minimum Power Rating (Voltage Limited By Power Dissipation or 300 VAC, Whichever is Less) +70 C......................................................................................................................................1 watt +125 C....................................................................................................................................0 watt Insulation Resistance (500 VDC)..................................................................1,000 megohms minimum 45 5 1.57 Resolution..................................................................................................................Essentially infinite (.062) 13.64 .38 7.14 + .00/- .05 DIA. 1 (.281+.000/-.002) (.537 .015) Environmental Characteristics 1/4 -32 UNEF-THD Operating Temperature Range...................................................................................+1 C to +125 C 3.170 + .000/-.008 Storage Temperature Range.....................................................................................-65 C to +125 C DIA. (.1248+.0000/.0003) Temperature Coefficient Over Storage Temperature Range...........................500 ppm/C maximum .25 45 5 X Vibration .........................................................................................................................................15 G (.010) CHAMFER Wiper Bounce...........................................................................................0.1 millisecond maximum 22.23 Total Resistance Shift ..............................................................................................5 % maximum (7/8) Voltage Ratio Shift ................................................................................................0.5 % maximum DIA. Shock .............................................................................................................................................50 G Wiper Bounce...........................................................................................0.1 millisecond maximum 9.53 Total Resistance Shift ..............................................................................................5 % maximum 3.18 (3/8) Voltage Ratio Shift ................................................................................................0.5 % maximum (1/8) 22.23 Load Life.................................................................................................................1,000 hours, 1 watt (7/8) Total Resistance Shift ............................................................................................10 % maximum .38 Rotational Life (No Load) .........................................................................20,000,000 shaft revolutions SHAFT SLOT (.015) .81 .81 Total Resistance Shift ............................................................................................10 % maximum WIDE X DEEP (.032) (.032) Moisture Resistance (MIL-STD-202, Method 106) Total Resistance Shift ............................................................................................10 % maximum TOLERANCES: EXCEPT WHERE NOTED IP Rating ........................................................................................................................................IP 40 .51 .127 DECIMALS: .XX .XXX (.02), (.005) 1 Mechanical Characteristics FRACTIONS: 1/64 MM Mechanical Angle ................................................................................................................Continuous DIMENSIONS: (IN.) Torque (Starting & Running)............................................................0.18 N-cm (0.25 oz.-in.) maximum Mounting.............................................................................170-200 N-cm (15-18 lb.-in.) maximum Shaft Runout................................................................................................0.025 mm (0.001 in.) T.I.R. WIPER Shaft End Play ...............................................................................................0.13 mm (0.005 in.) T.I.R. 2 Shaft Radial Play ...........................................................................................0.08 mm (0.003 in.) T.I.R. Backlash ........................................................................................................................0.1 maximum CCW CW 3 1 Weight..........................................................................................................................................18 gm CLOCKWISE Terminals.......................................................................................................................Rear turret type Soldering Condition Manual Soldering................................96.5Sn/3.0Ag/0.5Cu solid wire or no-clean rosin cored wire 370 C (700 F) max. for 3 seconds Wave Soldering ........................................................96.5Sn/3.0Ag/0.5Cu solder with no-clean flux Recommended Part Numbers 260 C (500 F) max. for 5 seconds Wash processes ..................................................................................................Not recommended Resistance Marking ................................Manufacturers name and part number, resistance value and tolerance, Part Numbers () linearity tolerance, wiring diagram, and date code Ganging (Multiple Section Potentiometers).................................................................1 cup maximum 6638S-1-102 1,000 Hardware ...................................................One lockwasher (H-37-1) and one mounting unit (H-38-1) is shipped with each potentiometer. 6638S-1-502 5,000 6638S-1-103 10,000 BOLDFACE LISTINGS ARE IN STOCK AND READILY 1 At room ambient: +25 C nominal and 50 % relative humidity, except as noted. AVAILABLE THROUGH DISTRIBUTION. FOR OTHER OPTIONS CONSULT FACTORY. REV. 10/08 *RoHS Directive 2002/95/EC Jan 27 2003 including Annex Specifications are subject to change without notice. Customers should verify actual device performance in their specific applications. *RoHS COMPLIANT