*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
13
2
13
2
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.
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.
STD.
6.35 ± .76
(.25 ± .03)
19.05
(.75)
DIA.
DIA.
12.19
(.480)
STD. STD.
.79 ± .25
(.031 ± .010)
2.36
(.094)
50 ° ± 10 °
Product Dimensions
13
CCW
POTENTIOMETER
2
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