general-purpose failsafe moulded wirewound resistors sp20/sp20f series drop-in replacement for bw20/bw20f predictable fusing characteristics 1 watt rated with 1/2 watt dimensions 0.1 ohm to 1200 ohms weldable and solderable magnetic leads general note welwyn components reserves the right to make changes in product specification without notice or liability. all information is subject to welwyn s own data and is considered accurate at time of going to print. ?welwyn components limited ?bedlington, northumberland ne22 7aa, uk telephone: +44 (0) 1670 822181 ?facsimile: +44 (0) 1670 829465 ?email: info@welwyn-tt.com ?website: www.welwyn-tt.com 95 type sp20 sp20f eia rs-344 style cru 1 mil-r-11 style rc20/rc32 resistance range ohms 0r1 to 1k2 0r1 to 1k tolerance % 5, ?0 power rating watts 1 at 50? 1 at 50? 0.75 at 70? 0.75 at 70? 0.5 at 100? - derating to 0 at 160? derating to 0 at 160? maximum continuous working voltage pr minimum insulation resistance dry 10,000 meg wet 100 meg minimum dielectric withstanding volts atm 700v reduced pressure rms 450v hotspot temperature rise 120? at 1 watt current noise negligible electrical data issue b ?03.02 a subsidiary of tt electronics plc welwyn components dimensions (mm) type l d d f sp20 9.91?.25 3.56?.20 0.813?.05 38.1?.2 sp20f 9.91?.25 3.56?.20 0.813?.05 38.1?.2 physical data l d f d resistive element all resistor types have resistance alloy winding on a braided fibreglass substrate. intermediate silicone coatings are used to enhance processibility and to provide protection to the resistive element. termination the sp20 and sp20f resistors are terminated using an alloy coated copper flashed steel lead welded to a cap of the same material. this termination assembly is mechanically crimped, utilizing an improved crimp design, to the resistive element. encapsulation the sp20 and sp20f are encapsulated utilizing a compression molded phenolic plastic material. the sp20f has a flame resistance coating applied over the resistive element to provide flammmability protection when destructive overloads may occur. marking all products are marked utilizing heat and solvent resistant colour code bands consistent with eia/mil requirements. the first band is double width to designate wirewound construction. a fifth band, blue in colour, is used for flameproof identification.
performance dat a t est f 0 2 p s 0 2 p s * 0 0 8 r 1 < 0 0 8 r 1 < c / m p p ) m p p ( t n e i c i f f e o c e r u t a r e p m e t 1r 150 1r 150 v 0 0 7 s m r e g a t l o v g n i d n a t s h t i w c i r t c e l e i d 5 % d a o l r e v o y r a t n e m o m 5 % n o i t a r e p o e r u t a r e p m e t w o l 5 % e l c y c e r u t a r e p m e t 5 % y t i d i m u h 5 % e f i l d a o l 5 % h t g n e r t s l a n i m r e t 5 % t a e h r e d l o s o t e c n a t s i s e r general-purpose failsaf e moulded w i r ewound resistor s sp20/sp20f serie s ? w elwyn components limited bedlington, northumberland ne22 7aa, uk t elephone: +44 (0 ) 1670 822181 facsimile: +44 (0 ) 1670 829465 email: info@welwyn-tt.com w ebsite: ww w .welwyn-tt.com 96 issue b 03.02 w elwyn components ambient t emperature ( c) power (watts) 2.5 2.0 1.5 1.0 0.5 0 0 5 0 10 0 15 0 200 ambient t emperature ( c) p o w e r ( w a t t s ) sp20 power derating sp20f power derating t ime (seconds) power (watts) 0.1 ohm 1 ohm 10 ohm 100 ohm 1000 ohm power input (watts) t emp ( c) sp20f t ypical fusing sp20 and sp20f t emperatu r e rise *0.1 ohm sp20f <1000 ppm. o r d e r i n g p r o ce d u r e e x a m p l e : sp 2 0 f a t 47 0 oh m s and 5% t o l e r an c e t ape pa ck ed on a r eel o f 4 000 p i e c e s ? s p 2 0 f ? 470 r j i t y p e v a l ue ( u s e i e c62 c ode ) t o l e r an c e ( u s e i e c62 c ode ) j 5 % k 1 0 % p a ck i ng i t ap e 4000 / r ee l s t and a r d
|
