Series 270
®
Commercial
Miniature 5/8"
(16mm) Diameter
Composition
Variable Resistors
• Miniature 5/8" (16mm) size
• Versatile mounting styles:
– bushing
– twist tab
– bend tab
– snap-in PC bracket
– solder lug or PC terminals
(shaft parallel or perpendicular to the panel)
• 100
Ω
to 5 Meg
Ω
resistance range
• Molded or metal shafts
• SPST power switches
• Single, tandem, or concentric units
• Panel seal
• Rear extended shaft
Electrical and Mechanical Specifications
Resistance Range
100
Ω
through 5 Meg
Ω
(linear taper).
Resistance Tolerance
Standard: ±20%
Special: Other tolerances available in most
resistance values.
Power Rating, Watts
1
/
4
watt per section through 100K
1
/
5
watt per section above 100K
Full rating @ 55°C derated to no load at 85°C,
linear taper, bushing mounted control on steel panel
4" x 4" x .050" (101.6mm x 101.6mm x 1.27mm).
(Derating required on two section controls.)
Voltage Rating
Bushings to Terminals:
High pot test, one minute — 750 VAC
Operating maximum
— 500 VDC
Across End Terminals:
350 VDC, load not to exceed listed wattage ratings.
Resistance Tapers
Standard: Linear, 10% Audio and 10% CCW Audio
Special tapers available to meet most requirements
Angle of Rotation
Total Rotation
Without Switch: 300° ± 5°
With Switch:
315° ± 5°
Effective Rotation
Without Switch: 300° (approximate)
With Switch:
290° (approximate)
Panel Mounting Information
Bushing Mount
Standard: Brass
(continued on next page)
Technical Data Sheet 1448C
Technical Data Sheet 1270E
CTS CORPORATION /
MANUFACTURER OF RELIABLE ELECTRONIC COMPONENTS
Electrical and Mechanical Specifications
(continued)
All Other Mounts
Standard: Twist tab (designated by “1”)
Special: Bend tab — 2 or 3 ears
Bracket mounted
Suggested Panel for Twist Tab
.042" thick (1.07mm)
Locating Lugs (Bushing Mount)
Standard: .312" (7.9mm) radius from center of control.
Special: .375" (9.53mm) radius from center of control.
Standard Position: Left side supplied unless otherwise
specified.
Other Positions:
Available with lug right side,
without lugs, or with lugs both
left and right sides.
Water Seal Construction
Controls are also available to prevent water
from entering the control through either the
O.D. of shaft and/or the bushing.
Concentric Tandem Units
Available in two combinations:
A
– .125" (3.2mm) diameter rear shaft
.250" (6.35mm) panel shaft
(3/8 – 32 or M9X.75)
B
– .156" (4.0mm) diameter rear shaft
.236" (6.0mm) diameter panel shaft
(3/8 – 32 or M8X.75)
Most metal shaft diameters can be used with
twist tab mountings. With bracket mount,
only .187 diameter shafts are used, with turn-down
available to obtain smaller diameters.
Metal
Lengths: Minimum .125" (3.2mm) beyond bushing;
special lengths as required.
Trims:
Plain round screwdriver slotted, flatted,
knurled. Other trims available
upon request.
Molded
Flatted and knurled with screwdriver slot available
in many lengths and diameters.
Terminal Information
Standard: T Solder lug formed 90° to the rear.
Special:
(See below)
T:
T:
U:
Solder lug perpendicular to shaft.
Solder lug formed 60° to the rear.
PC terminals formed 90° forward toward
mounting surface. Terminals extend .187"
(4.7mm) beyond mounting surface.
PC terminals formed 90° to the rear, away
from panel mounting. Terminals extend .520"
(13.2mm) from mounting surface.
Shaft and Bushing Information
Bushing Lengths Available
Standard: .187" or .250" (4.75mm or 6.35mm)
Special: .125" increments (3.2mm increments)
Thread Size
Standard:
1
/
4
" – 32
3
/
8
" – 32
M7 x .75
M8 x .75P
Special: As required
Molded Shafts Available
(Shown with preferred diameter bushing)
Bushing Mounted or Ear Mounted
SHAFT DIAMETER
INCH
.156
.187
.236
.250
MM
4.0
4.7
6.0
6.35
BUSHING DIAMETER
INCH
1/4" – 32
—
3/8" – 32
3/8" – 32
MM
M7X.75
M7X.75
M8X.75
M9X.75
V:
W: Wire wrap terminals — .156" (4.0mm) terminal
extension beyond base, formed 60° to the rear.
BX: PC terminals standard .438" (11.1mm) from
center line of control to PC board; straight
terminals extend .156" (4.0mm) into PC board.
X:
PC terminals standard .505" (12.8mm) from
center line of control to PC board, with .136"
(3.4mm) straight terminal extension beyond
PC board standoff.
PC terminals standard .602" (15.3mm) from
centerline of control to PC board, with .140"
(3.5mm) straight terminal extension beyond
PC board standoff.
Metal Shafts Available
(Shown with preferred diameter bushing)
Single or Dual Units
SHAFT DIAMETER
INCH
.125
.156
.187
.236
.250
MM
3.2
4.0
4.7
6.0
6.35
BUSHING DIAMETER
INCH
1/4" – 32
1/4" – 32
3/8" – 32
3/8" – 32
3/8" – 32
MM
M7X.75
M7X.75
M7X.75
M8X.75
M9X.75
Y:
(continued on next page)
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