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Printable version

RX255N .25W Ultra Precision Wire Wound Printed Circuit Resistor


RX255N .25W Ultra Precision Wire Wound Printed Circuit Resistor

Technical Information

Mounting
Thru-hole
Resistance
.1Ω to 150KΩ
Tolerance
±.01% (std.) from ±1% to ±.005%
TCR Char.
±5 PPM /°C.
Max Watts
.25
Max Volts
100
Lead Free
Yes
Temperature
-65°C. to +125°C.
Length
7.92mm (.312")
Diameter
6.35mm (.250")
Stability
to ±.001% per year @25°C
Type
Printed Circuit
Lead Dimensions
.025" dia. x 1.0" long; spacing: 0.200"
  • Detailed Images

  • Details and Order Info

  • Electrical & Physical Specs

  • Attributes & Derating Table

Click the arrows for more detailed images:

CAN'T FIND THE PART TO MATCH YOUR SPECS?

Then let PRC custom manufacture your wire wound resistor, sensor, or shunt with some of the shortest lead times in the industry. Engineering samples can be supplied at no cost to you in 7-10 days for most jobs. Computer tracking charts are available for reference with certain part types. If you need a specific marking on your part(s) we will custom print your order with the marking you desire & at no additional cost to you. If needed, you can interchange the size, shape, lead dimension, wattage, voltage, current, Ω value, tolerance, & TCR characteristics with most part types. Visit our Ultra-Precision RX Series & see if one of our other parts from the same series will satisfy all your requirements. If you still do not find a part that meets the exact specifications your application requires, simply follow the link Contact/Request For Quote & fill in all known spec fields. One of our highly trained engineers will review your objectives and see if we can modify one of our standard parts to satisfy all your requirements. If you are unsure how to accurately complete this form, give us a call & someone from our sales department will be more than happy to assist you.

ORDERING PROCEDURE

Our sales department is available to provide price, delivery, lead time & all other pertinent ordering instructions to companies within the U.S.A. If you wish to place an order in the United States, simply give us a call & ask for the Sales Department, our contact information is at the very top of every page. For companies outside the U.S.A., we have sales representatives in over 30 different countries to assist you. Click the link International Sales Representative Map to locate the representative nearest to your region & view their contact information. Our international representatives are readily available & eager to answer all inquiries regarding pricing, lead time, & ordering instructions along with any other questions.

Electrical & Physical Specifications:

A-Length:7.92mm (.312")
B-Diameter:6.35mm (.250")
C-Lead Dimensions: .025" dia. x 1.0" long
Lead Spacing: .200"

RX Series Engineering Attributes:

RESISTANCE & TOLERANCES
You can select any Ohmic value or decimal part of an Ohm with tolerances to ±.005%. 10Ω minimum resistance for ±.01% tolerance. See figure #2 shown below.
TCR CHARACTERISTIC
Standard:
100Ω & higher values: 0±5 ppm/°C.
For values below 100Ω: 0±15ppm/°C.
Special:
100Ω & higher: 0±1 ppm/°C. matching to 0±.5 ppm/°C.
Please specify temperature span of operation. The TCR is calculated between +25°C. & +100°C.
POWER VS. AMBIENT TEMPERATURE
All Ultra Precision Resistors are designed for full load based upon ±1% resistance tolerance providing the ambient temperature (+) plus the rise in temperature due to self-heating, does not exceed +125°C. Derated to zero power @ +145°C., See figure #1 shown below.
STABILITY
To ±.001%/yr. @ +25°C. with no Load.
REDUCTION OF THERMAL EMF USING COPPER TERMINALS:
Less than ±3 microvolts/°C. emitted.
INDUCTANCE
Standard parts in this series are inductively wound. Non-inductive balanced reverse pi windings are available, simply add suffix letter "N" to the part # when placing your order.
PROTECTIVE SEAL
Features a stress free base coat as well as an epoxy casing that is resistant to solder heat & solvents.
MARKING
PRC stamp, part type & name, Ω value & tolerance, physical size permitting.

 
Type RX Derating Table*
 
For ± 1% resistance tolerance apply up to 100% of rated power to +125 Degrees Celsius. derated to zero @ +145 Degrees Celsius.

For ± Ω&Om% (0.5%) resistance tolerance apply up to 75% of rated power to +125 Degrees Celsius. derated to zero @ +140 Degrees Celsius.

For ± _% (0.25%) resistance tolerance apply up to 50% of rated power to +125 Degrees Celsius. derated to zero @ +135 Degrees Celsius.

For ± 1/10% (0.1%) resistance tolerance apply up to 50% of rated power to +125 Degrees Celsius. derated to zero @ +135 Degrees Celsius.

For ± 1/20% (0.05%) resistance tolerance apply up to 35% of rated power to +125 Degrees Celsius. derated to zero @ +132 Degrees Celsius.