Heat Sinkable IS Series Resistor0 pages

THICK FILM

IS Series
HEAT
SINKABLE

Ultra Low Profile Power Resistors
F e at u r e s

• Heatsinkable
• Low profile
• High power
• Pulse handling capability
• Non-flammable
• Low inductances

• Available with fast-on
terminals or wire leads
• Rugged construction
• Ultra low profile thickfilm on steel
• 175W to 270W sizes
• Single fixing heatsink
mountable

uses

• Braking resistors
• In-rush current limiter
• Bleeder resistor

• Power switching
• Soft charging

S ERIE S S P ECI F ICATI O N S

Type
IS175
IS200
IS250
IS270

Power
Rating
(watts)
175
200
250
270

Resistance
Range
(Ω)
5Ω to 10KΩ
5Ω to 10KΩ
5Ω to 10KΩ
5Ω to 10KΩ

Construction
Tolerance
10%, 20%
10%, 20%
10%, 20%
10%, 20%

Dielectric Termination

Glass Overcoat
Resistive Glaze
Stainless Steel

characteristics

TCR <250ppm (surface temp less than 150°C)

Derating

Hot spot surface 200°C max.
temperature
Over-vlotage rating 5X rated power for up to for up to 1 second
Resistive element Thick Film
Derating element surface temp. at 100% to 0% power
at 200°C surface temp.

% Rated Power

Working voltage Not to exceed 300V

120

Power rating dependent on mounting and heatsink thermal capacity
Maximum element 365°C
temperature
Pulsed load at full Max. 1%ΔR; (see Fig 1)
pulse power rating Mounted on a 0.06°C/W heatsink with
1,000 cycles forced air cooling, air temperature 25°C (ref
AH32430 12" long)
Solder Silver solder is recommended for IS Series
resistors. Leaching of the silver in the termination will occur if non-silver solder is used.
60/40 tin-lead solders are not recommended
for use with the IS Series product.

1

1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com

100
80
60
40
20
0

0

50
100
150
200
Resistor Surface Temp., C

250

THIS PRODUCT IS
DESIGNED FOR USE WITH
PROPER HEATSINKING.
Maximum base plate temperature of
the resistor must be monitored and
kept within specified limits to establish the power rating. Best technique
is to attach a thermocouple to the
side of the base plate of the resistor.