PCF233KOHMK - KOA Speer Electronics, Inc.

SS-02 R3

PAGE 1 OF 8

Fixed Ceramic Composition Resistors

Type PCF

1. Scope of Application

This specification relates to non-flammable coated, insulated type, fixed

ceramic resistors (type PCF) manufactured by KOA T&T Corporation.

Table 1 Power Rating

Item 1/4 1/2 1 2

Resistance range (Ω) 4.7 ~ 100K 3.3 ~ 1M

Max. working voltage (V) 150 200 300 400

Max. overload voltage (V) 300 400 600 800

Max. pulse voltage (KV) 8 10 14 20

Withstanding voltage (V) 400 500 700

Min. ambient temp. (°C) -40

Max. ambient temp. (°C) 200

Rated ambient temp. (°C) 70

K(±10%), M(±20%)

Resistance tolerance K(±10%) as per E12

M(±20%) as per E6

3. Type Designation

2. Rating

3.1 Marking

The resistors shall be marked with color codes as per EIA-172.

PCF

Type Power Rating Nominal Resistance Resistance Tolerance

Non-flammable coated,

insulated type,

fixed ceramic

composition resistors

1/4

1/2

1/4----4.7 ~ 100K

1/2----4.7 ~ 100K

1----3.3 ~ 1M

2----3.3 ~ 1M

K:±10%

M:±20%

1/2 10k ΩK

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

PAGE 2 OF 8

SS-02 R3

3.2 Derating Curve

Under ambient temperature in excess of 70°C, the

load shall be derated as shown in the figure below.

3.3 Rated Voltage

Resistors shall have a rated direct current

(DC) continuous working voltage or an

approximate sine wave rootmean square

(rms) alternation-current (AC) continuous

working voltage at commercial line frequency

and wave form corresponding to the power

rating, as determined from the following

formula:

In no case shall the rated DC or rms AC

continuous working voltage be greater than

the applicable maximum value.

Where, E =

√

P x R

E = Rated DC or rms AC

continuous working voltage (V)

P = Power rating (W)

R = Nominal resistance (OHM)

Ambient Temperature (°C)

Percent Rated Wattage (%)

100

100 200700-40

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

SS-02 R3

4. Structure and Dimension

PAGE 3 OF 8

Type Designation D L C max. H d

PCF1/4 2.5 ± 0.5 6.2 ± 0.5 7.1 30 ± 3 0.6

PCF1/2 3.5 ± 0.5 9.0 ± 1.0 11.1 0.7

PCF1 5.5 ± 1.0 16.5 ± 1.0 19.0 38 ± 3 0.8

PCF2 7.0 ± 1.0 19.0 ± 1.0 22.5

No. Name Material Remarks

1 Resistor Ceramic composition Ceramics

2 The edge of resistor Silver

cap: Iron Cap surface treatment:

First plated with copper, then tin

3 Terminal Terminal wire: Terminal wire surface treatment:

Annealed copper wire Plated with solder

Connection of cap to terminal wire: Weld

4 Coating Non-inflammable insulating silicone coating material color:

Light Green UL-94 V-0 approved material

Type Designation 1/4 1/2 1 2

Allowable uncoated area 1.0 1.5 2.2 2.9

of resistor end surface

Maximum allowable uncoated area of resistor end surface.

4 1 2 3

d (nominal)

unit: mm

unit: mmD

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

SS-02 R3

5. Characteristics

PAGE 4 OF 8

Nominal Resistance

Range

3.3 to 9.1 ohms

10 to 91 ohms

100 to 910 ohms

1k to 9.1k ohms

10k to 91k ohms

100k to 1M ohms

Resistance

Tolerance

±10%

±20%

0.3

1.0

3.0

Recommended Test

Voltages (DC Volts)

In the event of a difference in resistance readings

attributable to the test voltage used, the specified

test voltage listed below shall be used.

Resistors shall be maintained within ± 1°C at the

ambient temperatures listed below. The use of

forced circulating air is recommended to assure

temperature stability and uniformity. Resistance

measurements shall be made at each temperature

15 minutes after air temperature has stabilized at

the specified temperature.

The percent difference in resistance referred

to the resistance at +25°C shall be computed with

the following formula:

Percent Resistance = (R-r) x 100

Where: R is the resistance at test temperature

r is the resistance at +25°C

Difference r

Resistance to the

nominal resistance

should be in each

resistance tolerance

shown below.

-1300 ± 300ppm/°C

Resistance

(Method 303)

Temperature

Coefficient

(Method 304)

Characteristics Test MethodNo. Requirement

(MIL-STD 202)

Sequence

+25°C

-40°C

+25°C

+75°C

+125°C

Ambient Temperature

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

SS-02 R3

PAGE 5 OF 8

Voltage Coefficient

from 1k ohms ~

(Method 309)

0 ~ -0.2%/V

Within

± (2% + 0.05 ohm)

Resistance change shall

be ± (1% + 0.05 ohm) of

the Pre-test value, with

no terminal loosening,

and lead-wire break-

down developing.

Resistance change shall

be ± (2% + 0.05 ohm) of

the Pre-test value, with

no terminal loosening

and lead-wire break-

down developing.

Short Time Overload

Terminal Strength

(Method 211)

Vibration

(Method 201)

The resistance shall be measured at one-tenth the

RCWV and at full RCWV. Application of voltages

shall be momentary to minimize heating effects.

The resistance - voltage coefficient shall be

calculated with the following formula:

A well regulated DC or sine wave RMS voltage

2.5 times the RCWV, but not exceeding the limit

values listed in Table 1, shall be applied for 5

seconds. Resistance shall be measured before

and approximately 30 minutes after the application

of the test voltage.

Initial resistance shall be measured. The frequency

shall be varied approximately logarithmically

between the nominal limits of 10 to 55 Hertz with

a return sweep to 10 Hertz shall be traversed in

approximately 1 minute. This sweep cycle shall

be performed repeatedly for 2 hours in each three

directions to perpendicular. Final measurements

and examination for mechanical failures shall be

made after the test.

Voltage Coefficient = (R-r) x 100

Where: R is the resistance at full RCWV

r is the resistance at one-tenth RCWV

Percent Per Volt r x 0.9 (RCWV)

Test Item Lead wire (D) (mm) Test

Ø 0.6, 0.7 Ø 0.8 Method

Tensile 10N 20N 30 ± 5 sec

Strength (1.02kgf) (2.04kgf)

Bending 0.51kgf ––––––– 5N (0.5kgf)

Strength ––––––– 1.02kgf 10N (1.02kgf)

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

SS-02 R3

PAGE 6 OF 8

Initial resistance shall be measured. Resistor leads

shall then be immersed, one at a time for 3.5 ± 0.5

sec. each, in molten solder at +350°C ± 10°C to a

distance of 2 - 2.5mm from the resistor body. Final

resistance shall be measured 2 ± 1 hr. after the

immersions.

Resistance change shall

be ± (2% + 0.05 ohm)

of the Pre-test value with

no mechanical damage

in appearance and

marking.

Resistance to

soldering heat

(Method 210)

Solderability

(Method 208)

Resistance

to solvents

Dielectric

withstanding voltage

(Method 301)

Over 3/4th of the lead-

wire surface area shall

be covered with solder,

when judged visually.

No evidence of

mechanical damage

in appearance and

marking.

The resistor develops

no dielectric breakdown.

Resistance change shall

be ± (1% + 0.05 ohm)

of the Pre-test value.

The lead-wire is immersed for 2 - 3 seconds

in methanol solution containing rosin body is

immersed in melted solder at temperature of

235 ±5°C for a period of 3 ± 0.5 sec. as far as

the point 2 - 2.5mm from the resistor body.

1. Sample shall be immersed in ultrasonic

solvents of 28kHz frequency, 150w (0.3w/cm2)

power at 35 ± 5°C for 2 minutes.

2. After samples shall be immersed in specified

solvents (following table) for 3 minutes, the resistor

shall be immediately wiped with a dry cloth

(velvet or gauze)

(Solvents)

1. Iso-proryle alcohol

2. 1-1-1 trichloroethane

The resistors shall be clamped in the trough of a

90°C metallic V-block of such size that the resistor

body does not extend beyond the ends of the

trough. The resistor leads shall be positioned such

that they are no closer to the V-block than if they

were parallel to the sides of the V-block. This

prevents unnecessary proximity of the leads to

the block, while permitting complete seating of

the resistor body in the block.

Sine wave RMS voltages from an alternating

current supply at commercial line frequency not

more than 100 Hertz as specified in Table 1 shall

be applied at the rate of approximately 100 volts

per second between resistor terminals connected

together and the V-block, and held for 5 seconds.

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

PAGE 7 OF 8

SS-02 R3

The coating cab withstand the overload test, with no possibilities of ignition.

1. Overload Test as per UL-492, Item 13:

A piece of cotton cloth (A piece of gauze untreated corresponding to Nos 32-28

that measures 36 inches in width and 14 - 15 yards per pound) is wound around

a resistor. Then, the resistor is applied with voltage which is increased by two

times, three times, . . . ten times the rated voltage at intervals of one minute till

the resistor is broken down. If the cotton cloth is found igniting, the resistor shall

be considered unacceptable.

The coating is completely proof against any kind of heat sources. Even if

exposed to gas burner flames or heated red with nichrome wire wounded, the

coating will not flame, nor soften and melt to drop.

2. Hot-wire Ignition Test as per UL-492-2, Item 9:

A nichrome wire (Mixture of Cr 20% and Ni 80% which measures 0.0201 inches

in diameter and 865 feet per pound, and having 1.61 ohm per foot) is wound a

resistor at intervals of 1/4 inch so as to result in power consumption of 65W or

more. Then, the resistor is heated red with electricity supplied to the nichrome

wire.

Flame-proof

(UL-492-2)

Test circuit is shown below.

1 sec. on and 1 sec. off 20,000 cycles.

The voltage is applied with maximum pulse volt-

age shown in Table 1.

Initial resistance shall be measured. The resistors

shall then be exposed to the air stream at -40°C ±

3°C for 24 hours with no voltage applied, after

which the resistors shall be placed at room

temperature, final resistance shall be measured.

Resistance change shall

be ± 5% of the Pre-test

value.

Resistance change shall

be ± 5% of the Pre-test

value.

Resistance to pulse

Low Temperature

Operation

10k ohm

C = 1000pF Rx

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

KOA SPEER ELECTRONICS, INC.

PAGE 8 OF 8

SS-02 R3

14 Thermal Shock

(Method 107)

Resistance change shall

be ± (2% ± 0.05 ohm) of

the Pre-test value.

Moisture Resistance

Moisture Life

(Method 103)

Operating Life

(Method 108)

Resistance change shall

be ± 5% of the Pre-test

value.

Resistance change shall

be ± 5% of the Pre-test

value.

Resistance change shall

be ± 5% of the Pre-test

value.

Initial resistance shall be measured. The resistors

shall be subjected to the temperature cycle speci-

fied below for a total of five cycles, performed con-

tinuously. Temperatures in Steps 1 and 3 shall be

maintained by forced air circulation. The hot and

cold chambers shall be of such capacity that air

temperature will reach the temperatures specified

in Table 4 within 2 minutes after the resistors have

been placed in the appropriate chamber. Final

resistance shall be measured approximately one

hour after completion of the fifth cycle.

Initial resistance shall be measured before the

test. Resistors shall be exposed to a temperature

of 40 ± 2°C and a relative humidity of 90 - 95%, for

1,000 hours. After removal from the chamber, the

resistors shall be allowed to dry at room ambient

for approximately one hour. Final resistance shall

be measured.

Initial resistance shall be measured. Resistors

shall be placed in a chamber at relative humidity of

90 - 95% at ambient temperature of 40 ± 2°C.

Then DC RCWV shall be applied intermittently

1-1/2 hr. (on), 1/2 hr. (off) for a total of 1,000 hrs.

After removal from the chamber, the resistors shall

be allowed to dry at room ambient for approxi-

mately 1 hr. Final resistance shall be measured.

Initial resistance shall be measured. Resistors

shall be placed at ambient temperature of 70 ±

3°C. Then DC RCWV shall be applied intermittent-

ly 1-1/2 hr. (on), 1/2 hr. (off) for a total of 1,000 hrs.

After return to room temperature, final resistance

shall be measured.

Thermal Shock Test Sequence

Step Temperature (°C) Time (min.)

1 -40 ± 3 30

2 +25 ± 5 10 ~ 15

3 +85 ± 2 30

4 +25 ± 5 10 ~ 15

Bolivar Drive

■

P.O. Box 547

■

Bradford, PA 16701

■

USA

■

814-362-5536

■

Fax 814-362-8883

■

www.koaspeer.com

AHA 03/01

Notice: The information contained in this Spec Sheet is believed to be accurate and up-to-date. KOA Speer Electronics reserves this right to change these specifications without notice.

KOA SPEER ELECTRONICS, INC.