VISHAY SFERNICE www.vishay.com Resistive Products Application Note Wirewound Rheostats and Potentiometers Characteristics FEATURES RHEOSTAT MODE • 12 W to 500 W at 25 °C • CCTU 05-03B • Material categorization: For definitions of compliance please see www.vishay.com/doc?99912 The performance of RT-RTE rheostats exceeds the requirements of specification CCTU 05-03B. They have been designed for heavy duty applications such as repeated overloads, transients, shock and vibration conditions. G RT VITREOUS SERIES Z Six sizes are available capable of dissipating 12 W, 25 W, 55 W, 100 W, 250 W or 500 W at 25 °C. The resistive wire is protected by a proprietary Vishay Sfernice enamel fired at high temperature and free from any compound that could cause corrosion of the wire. The maximum operating temperature of the RT series is 320 °C. POTENTIOMETER MODE GANGED UNITS Ganged units are available with different combinations of power and ohmic values (see datasheet). Z GRADED WINDINGS I max. These are recommended when the ratio is ----------- 2 I min. 1.28 MAXIMUM OVERLOAD In rheostat use, the winding current decreases in relation to the number of turns being used. When part of the winding is used the current can be increased in accordance with the graph on the left. Substantially heavier overloads can be applied in short impulses and we would be pleased to advise on this type of application, on receipt of the following information: 1.24 1.20 1.16 1.12 - proposed rheostat usage 1.08 - current level 1.04 1 0 15 30 45 60 75 90 100 - operating cycles specifying duration of overload “ON”, “OFF” periods WINDING IN SERVICE in % Revision: 06-Aug-13 Document Number: 50024 1 For technical questions, contact: [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 APPLICATION NOTE CURRENT INCREASE FACTOR OVER NOMINAL G Application Note www.vishay.com Vishay Sfernice Wirewound Rheostats and Potentiometers Characteristics SPECIAL FEATURES OFF POSITION LEFT Code No.: 213700 OFF POSITION RIGHT Code No.: 213600 FIXED TAPPINGS, ONE OR MORE Code No.: RTP Not available for RT12 and RT500 ? c a c b b IDLE LUG LEFT Code No.: DB1 Not available for RT12 and RT500 a c a b IDLE LUG RIGHT Code No.: DB2 Not available for RT12 and RT500 DOUBLE MINI SWITCH Not available for RT12 L c a Idle lug c Idle lug c b b REDUCED LEFT TRAVEL Not available for RT12 and RT500 REDUCED RIGHT TRAVEL Not available for RT12 and RT500 c a a APPLICATION NOTE b c b Other special features are available. Please consult Vishay Sfernice for all of your rheostat requirements. All the positionings are defined when the shaft end is viewed (contrary to the above windings) clockwise detent. DIMENSIONS in millimeters DOUBLE MINI SWITCH FOR SERIES AND SIZE CODE L RT25 219410 29 RT55 219430 33 RT100 219450 33 RT230 219470 35 RT500 219480 35 Revision: 06-Aug-13 Document Number: 50024 2 For technical questions, contact: [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Application Note www.vishay.com Vishay Sfernice Wirewound Rheostats and Potentiometers Characteristics POWER RATING RATED POWER IN % 125 100 75 RT 50 RT E 25 0 0 50 150 100 200 250 300 350 AMBIENT TEMPERATURE IN °C 00 0 RT 5 RT 23 RT1 00 250 RT 55 2 300 RT 2 5 350 RT 1 TEMPERATURE RISE AT HOTTEST POINT IN °C TEMPERATURE RISE 200 150 100 50 0 1 5 10 100 1000 NOMINAL DISSIPATION IN (W) ORDERING INFORMATION RT 025 ASF 2201 K B XXX MODEL STYLE SPINDLE OHMIC VALUE TOLERANCE PACKAGING SPECIAL DESIGN GLOBAL PART NUMBER INFORMATION APPLICATION NOTE R GLOBAL SIZE MODEL RT T LOCKING DEVICE (OPT.) 025 Revision: 06-Aug-13 D 0 2 WINDING (OPT.) 5 A COMMAND SHAFT S 1 0 R OHMIC VALUE The three first digits are AS = Standard significant figures and the (diam: 6 mm) last digit specifies the AM number of zeros to follow. AMF R designates decimal point. AL As applicable 2002 = 20 k ASF xxx(x) = 4700 = 470 Internal 10R0 = 10 number 0R01 = 0.01 BXXX or BXXXX 0 K B TOLERANCE PACKAGING J=5% K = 10 % B = Bulk BO10 SPECIAL As applicable Ex = DXxx No standard packaging: N = Bulk, qty. open Document Number: 50024 3 For technical questions, contact: [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000