6638_08 Datasheet, PDF (1/1 Pages) Bourns Electronic Solutions – Precision Potentiometer

*RoHS ^COMPLIANT
Features
■ 7/8 ” (22 mm) diameter single-turn
conductive plastic
■ Bushing mount
■ Excellent resolution
■ High rotational life – ball bearing
shaft support
■ Non-standard features and
specifications available
6638 - Precision Potentiometer
Electrical Characteristics¹
Standard Resistance Range....................................................................................1 K to 100 K ohms
Total Resistance Tolerance .........................................................................................................±10 %
Independent Linearity ...................................................................................................................±1 %
Effective Electrical Angle .......................................................................................................340 ° ±3 °
End Voltage .................................................................................................................0.5 % maximum
Output Smoothness ....................................................................................................0.1 % maximum
Dielectric Withstanding Voltage (MIL-STD-202, Method 301)
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
Resolution..................................................................................................................Essentially infinite
Environmental Characteristics¹
Operating Temperature Range...................................................................................+1 °C to +125 °C
Storage Temperature Range.....................................................................................-65 °C to +125 °C
Temperature Coefficient Over Storage Temperature Range ...........................±500 ppm/°C maximum
Vibration .........................................................................................................................................15 G
Wiper Bounce ...........................................................................................0.1 millisecond maximum
Total Resistance Shift ..............................................................................................±5 % maximum
Voltage Ratio Shift ................................................................................................±0.5 % maximum
Shock .............................................................................................................................................50 G
Wiper Bounce ...........................................................................................0.1 millisecond maximum
Total Resistance Shift ..............................................................................................±5 % maximum
Voltage Ratio Shift ................................................................................................±0.5 % maximum
Load Life .................................................................................................................1,000 hours, 1 watt
Total Resistance Shift ............................................................................................±10 % maximum
Rotational Life (No Load) .........................................................................20,000,000 shaft revolutions
Total Resistance Shift ............................................................................................±10 % maximum
Moisture Resistance (MIL-STD-202, Method 106)
Total Resistance Shift ............................................................................................±10 % maximum
IP Rating ........................................................................................................................................IP 40
Mechanical Characteristics¹
Mechanical Angle ................................................................................................................Continuous
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.
Shaft End Play ...............................................................................................0.13 mm (0.005 in.) T.I.R.
Shaft Radial Play ...........................................................................................0.08 mm (0.003 in.) T.I.R.
Backlash ........................................................................................................................0.1 º maximum
Weight ..........................................................................................................................................18 gm
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
260 °C (500 °F) max. for 5 seconds
Wash processes ..................................................................................................Not recommended
Marking ................................Manufacturer’s name and part number, resistance value and tolerance,
linearity tolerance, wiring diagram, and date code
Ganging (Multiple Section Potentiometers) .................................................................1 cup maximum
Hardware ...................................................One lockwasher (H-37-1) and one mounting unit (H-38-1)
is shipped with each potentiometer.
1_{At room ambient: +25 °C nominal and 50 % relative humidity, except as noted.}
Product Dimensions
6638
7/8 " (22 mm) DIA.
5.08
(.20) ^R
2
CW
3
1
1.57
13.64 ± .38 ^(.062)
(.537 ± .015)
22.23
(7/8)
DIA.
45 ° ± 5 °
7.14 + .00/- .05
(.281+.000/-.002)
DIA.
1/4"-32 UNEF-THD
3.170 + .000/-.008
(.1248+.0000/.0003) ^DIA.
.25
45 ° ± 5° X
CHAMFER
(.010)
9.53
3.18
(3/8)
(1/8)
22.23
(7/8)
.38
(.015)
SHAFT SLOT
.81
(.032)
WIDE
X
.81
(.032)
DEEP
TOLERANCES: EXCEPT WHERE NOTED
DECIMALS: .XX ±
.51
(.02),
.XXX
±
.127
(.005)
FRACTIONS: ±1/64
DIMENSIONS:
MM
(IN.)
2 ^WIPER
CCW ₁
CLOCKWISE
3 CW
Recommended Part Numbers
Part Numbers
Resistance
(Ω)
6638S-1-102
6638S-1-502
6638S-1-103
1,000
5,000
10,000
BOLDFACE LISTINGS ARE IN STOCK AND READILY
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.