scope:

This specification covers the general requirements for nonwire-wound variable resistors having a film resistance element shaped in an arc, and a contact bearing uniformly thereon, so that a change in resistance is produced between the terminal of the contact and the terminal of either end of the resistance element then the operating shaft is turned. These resistors are capable of full-load operation (where maximum resistance is engaged) at a maximum ambient operating temperature of 125°C, and are suitable for continuous operation, when-properly derated at a maximum temperature of 175°C (see 6.7 and table II). Table I of supplement 1 provides a summary of performance characteristics for these resistors.

The type designation shall be in the following form, and as specified (see 3.1 and 6.1):

The style is identified by the three-letter symbol "RVC" followed by a one-digit number; the letters identify variable resistors and the number identifies the size and power rating.

The type of bushing is identified by a single letter in accordance with table I. TABLE I. Bushing.

Symbol Bushing ------------------------------------ N- - - - - - Standard L- - - - - - Locking S- - - - - - Shaft and panel seal (standard) T- - - - - - Shaft and panel seal (locking)

The temperature and moisture characteristic is identified by a single letter in accordance with table II.

The operating shaft style shall be round with the dimensions as specified (see 3.1 ).

The nominal total resistance value expressed in ohms is identified by a three digit number; the first two digits represent significant figures and the last digit specifies the number of zeros to follow.

The resistance characteristic is identified by a single letter in accordance with table III. TABLE III. Resistance characteristic.

Symbol Resistance taper Resistance (see figure 2) tolerance --------------------------------------------------- Percent(±) B - - - - - - A ( linear CW ) 10 C - - - - - - C (10% CW) 10

The type designation RVC5NYB103B signifies:

RVC5 - A variable, nonwire-wound resistor of the dimensions and power rating specified (see 3.1 ). N - Standard bushing as specified in table I. Y - Temperature and moisture-resistance charac- teristic as specified in table II. D - Shaft ⅞ inch long. 103 - Nominal total resistance value of 10,000 ohms. B - Linear taper with resistance tolerance of ±10 percent.