PTCSC17T155DBE Vishay, PTCSC17T155DBE Datasheet - Page 4

• Manufacturer Part Number: PTCSC17T155DBE
• Description: PTC SS CHP 1717 155C 030 145 B E4
• Manufacturer: Vishay

Specifications of PTCSC17T155DBE

• Lead Free Status / RoHS Status: Supplier Unconfirmed

APPLICATION SPECIFIC DATA
Negative Temperature Coefficient (NTC) thermistors are well known for temperature sensing. What is not well known, however,
is that Positive Temperature Coefficient (PTC) thermistors can be used for thermal protection. Although their operating principles
are similar, the applications are very different; whereas NTC thermistors sense and measure temperature over a defined range,
PTC thermistors switch at one particular temperature.
Just like thermostats they protect such equipment and components as motors, transformers, power transistors and thyristors
against overtemperature. A PTC thermistor is less expensive than a thermostat, and its switch temperature can be more
accurately specified. It is also smaller and easier to design-in to electronic circuitry.
The PTC thermistor is mounted in thermal contact with the equipment to be protected, and connected into the bridge arm of a
comparator circuit, such as shown in Fig. 1. At normal temperature, the PTC thermistor resistance (R
Fig. 2), so the comparator's output voltage V
heat up to its trigger or nominal reference temperature T
causing V
APPLICATION EXAMPLES
Document Number: 29017
Revision: 08-Jun-09
R1
R2
O
to switch to a high level sufficient to activate an alarm, relay or power shutdown circuit.
Fig. 1 Typical comparator circuit
+ θ
R
PTC
thermistor
R
s
p
As soon as one or more of the windings becomes too hot, the
motor is switched off.
R
f
for Over-Temperature Protection
For technical questions, contact:
Fig. 3 Temperature protection of electric motors
+ θ
O
PTC Thermistors, Mini Chips
will be low. If an equipment overtemperature occurs, the PTC thermistor will quickly
+ θ
R
L
+ θ
n
, whereupon its resistance will increase to a value much higher than R
V
O
V
2381 671 910../PTCSC..T....BE
O
[e-mail]
(R1 = R2)
R
p
< R
Fig. 2 Typical switch characteristic
s
temperature
Trigger
T
Vishay BCcomponents
n
(R1 = R2)
R
p
p
) is lower than R
> R
s
T (°C)
www.vishay.com
s
(see
59
s
,