Document Number: 23088

Revision 14-May-02

www.vishay.com

10

307C Lighting Thermistors

Vishay Cera-Mite

ceramite.support@vishay.com

FEATURES

• Electrode preheat thermistors for use in compact

fluorescent lamps (CFL) and electronic ballasts.

• Current limiting, time-delayed start-up extends lamp life.

• Quiet, flicker-free operation.

• Developed in cooperation with leading ballast designers.

• Both standard and custom parts are available.

• Economical, reliable and proven in millions of lamps

throughout the world.

APPLICATION CONSIDERATIONS

• Ignition time can be optimized to increase life of lamp.

resistance and application voltage, to control desired

electrode preheat current.

• Lamp preheat time is determined by time required for

thermistor to switch from low to high resistance state.

Preheat currents shown result in switch times of

approximately 1 second at 25

°C. Lower currents result in

longer switch times.

FLUORESCENT LAMP

C

PTC

RESISTANCE

INSTANTANEOUS

CONTINUOUS

PREHEAT

D

VOLTAGE

VOLTAGE

CURRENT

MAX.

PART

(OHMS)

(mA)

(mm)

NUMBER

150

265

80

215

4.5

307C1407

150

280

200

200

4.5

307C1414

50

175

50

430

5.5

307C1230

70

265

150

350

5.5

307C1654

100

260

95

370

5.5

307C1364

125

230

80

280

5.5

307C1259

150

235

90

260

5.5

307C1253

200

320

145

300

5.5

307C1223

240

350

150

260

5.5

307C1171

300

400

165

225

5.5

307C1225

380

410

170

205

5.5

307C1390

600

420

120

185

5.5

307C1252

600

460

200

170

5.5

307C1224

850

450

340

140

5.5

307C1622

100

340

265

390

7

307C1403

150

340

150

400

7

307C1306

180

350

165

380

7

307C1569

200

355

265

300

7

307C1375

300

370

75

270

7

307C1242

300

420

320

230

7

307C1360

500

480

400

190

7

307C1361

800

530

450

155

7

307C1362

850

520

175

190

7

307C1260

70

210

50

750

8.5

307C1367

70

300

140

725

8.5

307C1366

85

210

50

670

8.5

307C1363

150

400

100

550

8.5

307C1287

85

280

60

820

10

307C1258

100

310

90

750

10

307C1365

400

430

120

420

10

307C1422

PTC THERMISTORS FOR ELECTRONIC FLUORESCENT BALLASTS

5mm

max

Tinned Copper Clad Steel Wire

24 AWG when D

≤ 8.5mm

22 AWG when D

≥ 10mm

Note 2: Instantaneous Voltage - Maximum rms voltage permitted across thermistor during fluorescent lamp start-up cycle.

Note 3: Continuous Voltage - Maximum rms voltage continuously applied across thermistor during normal lamp operation.

Note 4: Preheat Current - rms current (60Hz) which switches thermistor to high resistance in approximately 1 second at 25

°C ambient.

Note 5: Size (mass) of PTC influences rate of I

Optional coating slightly increases switch time.

Note 6: P/N suffix (not shown) describes wire lead forms and other options.

32mm min

4.5mm

max.

LS = 5mm

D

Options:

• High Temperature Coating

• Short Clipped Leads

• Other Wire Forms and Lead

Spacings

12

3

4

5

6

PTC Thermistors For Electronic Fluorescent Ballasts