Features
n Single-turn (3851 and 3852)
n Linear and audio tapers
n 3-3/4-turn (3856)
n Wide resistance range
n Minimal depth package
n Good resolution
3851/3852/3856 - 3/4 ” Diameter Panel Control
*RoHS Directive 2002/95/EC Jan. 27, 2003 including annex and RoHS Recast 2011/65/EU June 8, 2011.
Specifications are subject to change without notice. The device characteristics and parameters in this data sheet
can and do vary in different applications and actual device performance may vary over time.
Users should verify actual device performance in their specific applications.
*RoHS COMPLIANT
LEAD FREE
*RoHS COMPLIANT
VERSIONS
AVAILABLE
LEAD FREE
VERSIONS ARE
RoHS COMPLIANT*
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
Eective Electrical Angle ..................................(Linear tapers) 250 ° ±5 ° ................................... (Linear tapers) 250 ° ±5 °
(Audio tapers) 225 ° ±5 ° ................................... (Audio tapers) 225 ° ±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 innite .............................................. Essentially innite
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 Coecient 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
3851 & 3852 .................................................................................................................................................................. 56.5 N-cm (5 lb.-in.)
3856 ..................................................................................................................................................................................... Continuous turn
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 ux.
Part can be wave soldered at 260 °C (500 °F) for 5 seconds, no wash process with no clean ux.
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.
1 At room ambient: +25 °C nominal and 50 %
relative humidity nominal, except as noted.
Specifications are subject to change without notice.
The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.
Users should verify actual device performance in their specific applications.
3851/3852/3856 - 3/4 ” Diameter Panel Control
Product Dimensions
9.53
(.38)
3/8-32 UNEF
19.05
(.75)
DIA.
3/8-32 UNEF
1/4-32 UNEF 1/4-32 UNEF
3/8-32 UNEF 3/8-32 UNEF.
6.35
(.25) 2.79
(.110)
3 PLCS.
14.02 ± .25
(.552 ± .010)
SOLDER LUG TERMINAL
13
2
13
2
SUGGESTED BOARD LAYOUT
STANDARD
PRINTED CIRCUIT TERMINAL
A, B & H BUSHINGS
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 .72 DIAMETER
(.724 DIA. AWG
STRANDED) WIRES.
(.028)
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)
9.91
(.390) 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 %
ANTI-ROTATION LUG
PROJECTS 1/16 INCH
ABOVE MOUNTING FACE.
(.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 °
2.67 ± .381
(.105 ± .015)
DIMENSIONS: MM
(INCHES)
13
CCW
POTENTIOMETER
2
Specifications are subject to change without notice.
The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.
Users should verify actual device performance in their specific applications.
3851/3852/3856 - 3/4 ” Diameter Panel Control
How To Order
REV. 05/18
3852 A - 28 2 - 103 A L
ELEMENT APPLICABLE
TAPER/TOLERANCE MODELS
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
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
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)
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
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
RoHS IDENTIFIER
CompliantL
Boldface features are Bourns standard options.
All others are available with higher minimum order
quantities.
AVAILABLE ONLY IN
SHAFT TYPE
(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
Consult factory for lengths not shown.
