3852A-202-102AL - Bourns, Inc.

*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.

3851/3852/3856 - 3/4 ” Diameter Panel Control

Initial Electrical Characteristics1

3851 3852/3856

Conductive Plastic Element Cermet Element

Standard Resistance Range

Linear Tapers (A, B, E, and H) ............................................................1 K to 1 megohm.........................................100 ohms to 1 megohm

Audio Tapers (C, D, F, and G) .............................................................1 K to 1 megohm.........................................1 K ohms to 1 megohm

Total Resistance Tolerance .....................................................................±10 % or ±20 %..........................................±5 % or ±10 %

Independent Linearity.............................................................................±10 %..........................................................(A & H tapers) ±5 %

Absolute Minimum Resistance ...............................................................2 ohms maximum........................................ 2 ohms maximum

Effective Electrical Angle ........................................................................250 ° ±5 °.....................................................250 ° ±5 °

Contact Resistance Variation .................................................................±1 %............................................................±3 % of total resistance or 3 ohms

(whichever is greater)

Dielectric Withstanding Voltage (MIL-STD-202, Method 301)

Sea Level............................................................................................900 VAC minimum.......................................900 VAC minimum

70,000 Feet ........................................................................................350 VAC minimum.......................................350 VAC minimum

Insulation Resistance (500 VDC) ............................................................1,000 megohms minimum...........................1,000 megohms minimum

Power Rating (Voltage Limited By Power Dissipation or 350 VAC, Whichever Is Less)

+70 °C ...............................................................................................(Linear tapers) 1 watt...................................(Linear tapers) 2 watts

(Audio tapers) 0.5 watt (Audio tapers) 1 watt

+125 °C ..............................................................................................0 watt

+150 °C ...................................................................................................................................................................0 watt

Theoretical Resolution............................................................................Essentially infinite ........................................Essentially infinite

Environmental Characteristics1

Operating Temperature Range ...............................................................-1 °C to +125 °C..........................................-1 °C to +125 °C

Storage Temperature Range...................................................................-65 °C to +125 °C........................................-65 °C to +150 °C

Temperature Coefficient Over Storage Temperature Range...................±1,000 ppm/°C............................................±150 ppm/°C

Vibration..................................................................................................20 G.............................................................20 G

Total Resistance Shift.........................................................................±2 % maximum ...........................................±2 % maximum

Voltage Ratio Shift..............................................................................±5 % maximum ...........................................±6 % maximum

Shock......................................................................................................100 G...........................................................100 G

Total Resistance Shift.........................................................................±2 % maximum ...........................................±2 % maximum

Voltage Ratio Shift..............................................................................±5 % maximum ...........................................±6 % maximum

Load Life.................................................................................................1,000 hours .................................................1,000 hours

Total Resistance Shift.........................................................................±10 % maximum .........................................±3 % maximum

Rotational Life (No Load) ........................................................................100,000 cycles ............................................50,000 cycles

Total Resistance Shift.........................................................................±15 % TRS maximum ................................±5 % or 5 ohms TRS whichever is greater

Contact Resistance Variation .............................................................±3 %............................................................±3 %

Moisture Resistance (MIL-STD-202, Method 103, Condition B)

Total Resistance Shift.........................................................................±10 % maximum ........................................±2 % maximum

IP Rating .................................................................................................IP 40 ............................................................IP 40

Mechanical Characteristics1

Stop Strength ..............................................................................................................................................................................................56.5 N-cm (5 lb.-in.)

Mechanical Angle ....................................................................................................................................................................280 ° ±5 ° / 3856 – 1350 ° ±50 °

Torque (Starting and Running) ..............................................................................................................A & B bushings 0.35 to 4.23 N-cm (0.05 to 6.0 oz.-in.)

C & E bushings 0.21 to 4.23 N-cm (0.3 to 6.0 oz.-in.)

3856 – 0.11 to 2.12 N-cm (0.15 to 3.0 oz.-in.)

Mounting (Torque on Bushing)......................................................................................................................................1.7-2.0 N-m (15-18 lb.-in.) maximum

Weight (Single Section) ................................................................................................................................................................................30 grams maximum

Terminals ........................................................................................................................................................................Printed circuit terminals or solder lugs

Soldering Condition ......................................................................Recommended hand soldering using Sn95/Ag5 no clean solder, 0.025 ” wire diameter.

Maximum temperature 399 °C (750 °F) for 3 seconds. No wash process to be used with no clean flux.

Part can be wave soldered at 260 °C (500 °F) for 5 seconds, no wash process with no clean flux.

Marking....................................................................................................Manufacturer’s trademark, wiring diagram, resistance, date code, and part number

Ganging (Multiple Section Potentiometers) ......................................................................................................................................................1 cup maximum

Hardware ............................................One lockwasher and one mounting nut is shipped with each potentiometer, except where noted in the part number.

1AT ROOM AMBIENT: +25 °C NOMINAL AND 50 % RELATIVE HUMIDITY NOMINAL, EXCEPT AS NOTED.

Features

■Single-turn (3851 and 3852)

■Linear and audio tapers

■3-3/4-turn (3856)

■Wide resistance range

■Minimal depth package

■Good resolution

*RoHS COMPLIANT

Specifications are subject to change without notice.

Customers should verify actual device performance in their specific applications.

3851/3852/3856 - 3/4 ” Diameter Panel Control

DIMENSIONS ARE: MM

(INCHES)

9.53

(.38)

3/8-32 UNEF

3851A/3852A 3851B/3852B

19.05

(.75)

DIA.

3/8-32 UNEF

1/4-32 UNEF

3851C/3852C

1/4-32 UNEF

3851E/3852E

3/8-32 UNEF

3856A

3/8-32 UNEF.

3856H

6.35

(.25) 2.79

(.110)

3 PLCS.

14.02 ± .25

(.552 ± .010)

Terminal Configuration

SOLDER LUG TERMINAL

SUGGESTED BOARD LAYOUT

STANDARD

PRINTED CIRCUIT TERMINAL

3851/3852/3856

A, B & H BUSHINGS

Shaft End Detail

3850 Family

SHAFT SLOT

ALIGNMENT

AT CCW

FLAT

ALIGNMENT

AT CCW

50 ° ± 10 °

6.35 ± .76

(.25 ± .03) .38

(.015)

19.05

(.75)

DIA.

12.7, 22.23

(1/2, 7/8)

45 ° X (.010)

CHAMFER

.25

DIA.

6.35+.03/-.05

(.250+.001/-.002)

SHAFT SLOT

1.19 WIDE X

.047

1.60+.38/.00

(.063+.015/-.000)

12.19

(.480) DIA.

DEEP

OPTIONAL FLAT

LONG OR FRONT BUSHING FOR SHAFTS UNDER

5.49

(.216)

16.00

(.63)

1.52

(.06)

28.58

(1-1/8)

OPTIONAL FLAT LONG OR

FRONT BUSHING FOR SHAFTS UNDER

.25

(.010)

1.52

(.06)

15.88

(5/8)

12.7

(.50)

6.35 ± .76

(.25 ± .03) .38

(.015)

15.88

(5/8)

45 ° X (.010)

CHAMFER

.25

DIA.

6.35+.03/-.05

(.250+.001/-.002)

DIA.

12.19

(.48)

DEEP

SHAFT SLOT

1.19 WIDE X

(.047)

1.60+.38/-.00

(.063+.015/-.000)

TYP.

12.7

(.50)

2 PLCS. EACH TERMINAL LUG

WILL ACCOMMODATE

THREE .81 DIAMETER

(.812 DIA. AWG

STRANDED) WIRES.

(.032)

6.35

(.25) TYP.

15.88 ± .38

(.625 ± .015)

1.02

(.040)

TYP.

6.35

(.25)

6.35

(.25)

6.35

(.25)

1.40

(.055)

DIA.

9.53

(.375)

10.31

(.406) DIA. 3.18

(.125) DIA.

9.53

(.375)

6.73

(.265) DIA. 3.18

(.125)DIA.

TOLERANCES EXCEPT AS NOTED:

DECIMALS: .XXX ± .127 .XX ± .38

FRACTIONS: ± 1/64

ANGLE: ± 3 %

(.005), (.015)

6.35 ± .76

(.25 ± .03)

6.35

(.25)

9.53, 22.23

(3/8, 7/8)

.38

(.015)

45 ° X (.010)

CHAMFER

.25 45 ° X (.010)

CHAMFER

.25

3.18 ± 0.25

(.125 ± .001)

DIA.

SHAFT SLOT

.79 WIDE X .76 DEEP

(.031) (.03)

9.53

(.38)

12.7

(1/2)

.38

(.015)

19.05

(.75)

DIA.

12.19

(.480)

3.18 ± .025

(.125 ± .001)

DIA.

SHAFT SLOT

.79 WIDE X .76 DEEP

(.03) (.031)

6.35 ± .76

(.25 ± .03)

.38

(.015)

9.53

(.38)

12.7

(.50)

DIA.

6.35+.03/-.05

(.250+.001/-.002)

1.19

(.047)

45 ° X (.010)

CHAMFER

.25

12.19

(.480) DIA.

1.60+3.81/-.000

(.063+.015/-.000)

DIA.

22.23

(7/8) STD.

45 ° X (.010)

CHAMFER

.25

22.23

(7/8) STD.

12.19

(.480) DIA.

19.05

(.75)

DIA.

19.05

(.75)

DIA.

6.35 ± .76

(.25 ± .03)

12.7

(.50)

9.53

(.38)

.38

(.015) DIA.

6.35+.03/-.05

(.250 ± .03)

.79

(.031)

3.18 ± .03

(.125 ± .003)

DIA.

STD.

6.35 ± .76

(.25 ± .03)

19.05

(.75)

DIA.

12.19

(.480)

STD. STD.

.79 ± .25

(.031 ± .010)

2.36

(.094)

50 ° ± 10 °

Product Dimensions

CCW

POTENTIOMETER

Specifications are subject to change without notice.

Customers should verify actual device performance in their specific applications.

SHAFT TYPE AVAILABLE ONLY IN

(FMS) & DIAMETER MODELS BUSHINGS

12 3/8 ” (9.53 mm) L X 1/8 ” (3.18 mm) D 3851, 3852 C

16 1/2 ” (12.7 mm) L x 1/4 ” (6.35 mm) D 3851, 3852 A

16 1/2 ” (12.7 mm) L x 1/8 ” (3.18 mm) D 3851, 3852 C, E

20 5/8 ” (15.88 mm) L X 1/4 ” (6.35 mm) D 3851, 3852 A, B

28 7/8 ” (22.20 mm) L X 1/4 ” (6.35 mm) D 3851, 3852 A, B

3856 A

3851, 3852 C, E

28 7/8 ” (22.20 mm) L X 1/8 ” (3.18 mm) D 3856 H

BUSHING APPLICABLE MODELS

A Plain 3/8 ” (9.53 mm) D x 3/8 ” (9.53 mm) L 3851, 3852, 3856

B Locking 3/8 ” (9.53 mm) D x 1/2 ” (12.7 mm) L 3851, 3852

C Plain 1/4 ” (6.35 mm) D x 1/4 ” (6.35 mm) L 3851, 3852

E Locking 1/4 ” (6.35 mm) D x 1/2 ” (12.7 mm) L 3851, 3852

H Plain 3/8 ” (9.53 mm) D x 3/8 ” (9.53 mm) L 3856 (3.18 mm D Shaft)

Consult factory for lengths not shown.

MODEL

3851 3/4 ” (19.05 mm) D Single-Turn C.P.

3852 3/4 ” (19.05 mm) D Single-Turn Cermet

3856 3/4 ” (19.05 mm) D 3-3/4-Turn Cermet

TERMINAL STYLE AND

SHAFT TYPE

1 Solder Lugs, Plain End

2 Solder Lugs, Slotted End

3 Solder Lugs, Flatted Shaft

5 PC Pins, Plain End

6 PC Pins, Slotted End

7 PC Pins, Flatted Shaft

ELEMENT APPLICABLE MODELS

TAPER/TOLERANCE

A Linear ±10 % 3852, 3856

B Linear ±20 % 3851

C Audio CW ±10 % 3852, 3856

D Audio CW ±20 % 3851

E Linear ±10 % 3851

F Audio CCW ±10 % 3852, 3856

G Audio CCW ±20 % 3851

H Linear ±5 % 3852, 3856

RESISTANCE

CODE/VALUE

(IN OHMS)

Model 3851

(102) 1 K

(252) 2.5 K

(502) 5 K

(103) 10 K

(253) 25 K

(503) 50 K

(104) 100 K

(254) 250 K

(504) 500 K

(105) 1 M

Models 3852/3856

(101) 100

(251) 250

(501) 500

(102) 1 K

(252) 2.5 K

(502) 5 K

(103) 10 K

(253) 25 K

(503) 50 K

(104) 100 K

(254) 250 K

(504) 500 K

(105) 1 M

How To Order

3851/3852/3856 - 3/4 ” Diameter Panel Control

Boldface features are Bourns standard

options. All others are available with higher

minimum order quantities.

REV. 04/10/09

3852 A - 28 2 - 103 A L

RoHS IDENTIFIER

L Compliant