BOURNS 3250

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Features
Multiturn / Wirewound / Sealed
Listed on the QPL for style RT22 per
MIL-R-27208 and RTR22 per
High-Rel MIL-R-39015
■ Panel Mount option available
■
■
3250/RT22/RTR22 - 1/2 ” Square Trimming Potentiometer
Electrical Characteristics
Standard Resistance Range
3250 .....................................10 to 50K ohms
RT22.....................................50 to 20K ohms
RTR22 ................................500 to 20K ohms
(see standard resistance table)
Resistance Tolerance .......................±5 % std.
(tighter tolerance available)
Absolute Minimum Resistance
......0.1 % or 1 ohm max. (whichever is greater)
Noise...............................100 ohms ENR max.
Resolution .....................See Resistance Table
Insulation Resistance .........................500 vdc.
1,000 megohms min.
Dielectric Strength
Sea Level........................................1,000 vac
80,000 Feet .......................................400 vac
Adjustment Travel ......................25 turns nom.
Environmental Characteristics
Power Rating @ 85 °C
3250 ..................................................1.0 watt
RT22/RTR22 ...................................0.75 watt
Power Rating @ 150 °C .........................0 watt
Temperature Range.............-65 °C to +150 °C
Temperature Coefficient
3250 ...........................................±50 ppm/°C
RT22/RTR22...............................±50 ppm/°C
Seal Test ......85 °C Fluorinert* (pin styles only)
Humidity ................MIL-STD-202 Method 106
3250 .................(2 % ∆TR; 100 Megohms IR)
RT22...................(1 % ∆TR; 10 Megohms IR)
RTR22 ..............(1 % ∆TR; 100 Megohms IR)
Vibration ...................................................30 G
(1 % ∆TR; 0.5 % + resolution ∆VR)
Shock .....................................................100 G
(1 % ∆TR; 0.5 % + resolution ∆VR)
Load Life
3250 ...............1,000 hours 1.0 watt @ 85 °C
(2 % ∆TR; 500 ohms ENR)
RT22 ............1,000 hours 0.75 watt @ 85 °C
(2 % ∆TR; 2 % + resolution ∆VR)
RTR22 ........10,000 hours 0.75 watt @ 85 °C
(3 % ∆TR; 2 % + resolution ∆TR)
Rotational Life.................................200 cycles
3250 ....................(2 % ∆TR; 500 ohms ENR)
RT22/RTR22 ..................................(2 % ∆TR)
3250P/RT22/RTR22 Common Dimensions
(Pin Styles)
1.98 DIA. THRU
(.078) (2 PLACES)
ADJ. SLOT
2.03 ± .38
(.080 ± .015) DIA.
.64
WIDE
X
(.024)
13.21
TYP.
(.520)
12.7
TYP.
(.500)
3.1
DEEP
X
(.122)
.89
(.035)
TYP.
2.54
(.100)
2.54
(.100)
6.35
(.250)
1.78
TYP.
(.070)
.71 ± .08
(.028 ± .003) DIA. TYP.
5.59
(.220)
3
12.7
(.500)
TYP.
1
13.33 ± .64
(.525 ± .025)
2.54
(.100)
6.35
(.250)
YELLOW
CCW
2
WIPER
3
1
GREEN
CW
CLOCKWISE
How To Order
3250 L - 1 - 103 M
Model
Style
Standard or Modified
Product Indicator
-1 = Standard Product
Resistance Code
Optional Suffix Letter
M = Panel Mount
(Factory Installed)
2
See “Mil-Spec Numbering System” for RT22/
RTR22 ordering information.
Consult factory for other available options.
3250W/RT22/RTR22
2.79
(.110)
3
2
1
Standard Resistance Table
2.54
(.100)
2.54
(.100)
3250W-66/RT22X/RTR22X
3
2
6.35
(.250)
2.79
(.110)
1
2.54
(.100)
"L" Flex Lead Type
RT22 has mounting slots
RTR22 has mounting holes
6.35
2.54 (.250)
(.100)
13.21
TYP.
(.520)
2.36 DIA. THRU
(.093) (2 PLACES)
Physical Characteristics
Torque ......................................5.0 oz-in. max.
Mechanical Stops ..........................Wiper idles
Terminals
3250..............Solderable printed circuit pins
Flexible leads (7 strands of 30 AWG)
RT22/RTR22 .......MIL-STD-202; Method 208
Weight .................................................0.06 oz.
Machine Screw Mounting
Torque .....................................12 oz-in. max.
Marking
3250.....................Manufacturer’s trademark,
resistance code, terminal numbers,
date code, manufacturer’s model
number and style
RT22/RTR22 ..............Mil-spec part number
Wiper ........................................Set at CW end
Flammability....................................U.L. 94V-0
Standard Packaging
P&W Styles..........................25 pcs. per tube
L Style...................................25 pcs. per bag
Adjustment Tool .......................................H-90
RED
.89
TYP.
(.035)
12.70
TYP.
(.500)
1.40
(.055)
4.75
(.187)
1.52
(.060) TYP.
Resistance
(Ohms)
10
20
50
100
200
500
1,000
2,000
5,000
10,000
20,000
25,000
50,000
Nominal
Resistance
Code
100
200
500
101
201
501
102
202
502
103
203
253
503
Resolution
(Percent)
1.30
1.00
0.80
0.90
0.70
0.60
0.40
0.30
0.25
0.19
0.16
0.14
0.13
Popular values listed in boldface. Special
resistances available.
SHADED AREAS TYPICALLY NOT STOCKED BY
DISTRIBUTORS AND NOT RECOMMENDED FOR NEW
DESIGNS.
152.4
LENGTH (6.00) MIN.
12.7
(.500)
TOLERANCES: ± 0.25 (.010) EXCEPT WHERE NOTED
DIMENSIONS ARE:
MM
(INCHES)
REV. 02/03
*”FLUORINERT” IS A REGISTERED TRADEMARK OF 3M CO.
Specifications are subject to change without notice.