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Threshold thermistor TRP68-01
 The directly heated thermistor TRP68-01 are intended to operate as built-in elements inside thermal and other annunciators, including combined fire alarms, as well as for operation in electrical products for maintenance of temperature and temperature protection. Thermistors have relay (threshold) dependence of resistance on temperature.
• hysteresis less than 7°Ñ • high reliability • high sensitivity
• long service life
applications
• Sensors for temperature protection, control and limiting. • Voltage, current and frequency limiters in electronics.
Examples:
→ Overtemperature protector for power semi-conductors, such as transistors, power output stages, amplifiers. → Temperature control of electronic appliances and electric equipment. → Temperature sensors for signaling systems and fire detectors. → Control of componentry in industrial and entertainment electronics. → Protection of electronic circuits, such as computers or battery chargers.
operating principle
Vanadium dioxide (VO2) film is used as a temperature-sensitive element in the thermal resistor. Vanadium dioxide is a compound with metal-semiconductor phase transition (MSCPT). At a temperature below the MSCPT temperature [(68°1) C] the dependence between the thermal resistor resistance and the temperature is typical for semi-conductor materials having temperature resistance coefficient (TRC) of about 3%K-1. Thermal resistor resistance decreases stepwise near the MSCPT temperature, thus the TRC value achieves 2000%K-1. At a temperature above the MSCPT temperature the resistance remains practically the same.
resistance-temperature relationship
overall and mounting dimensions in mm
Lead wire length L, mm | Lug length L1, mm | Total length L2, mm | 13.5±1.0
23.0±1.0 | 25.0
33.5
Lug length may vary within 10.0 to 33.5 mm range as agreed. | Total length L2 is defined as the sum of lead wire length L and lug length L1, reduced by the connection length, which cannot be less than 4.0 mm. |
SPECIFICATIONS
Actuation temperature
Heat-capacity lag (deadband)
Thermal time constant
Thermistor resistance*:
at plus (23±3)°Ñ, R23
at plus (50±1)°Ñ, R50
at plus (75±1)°Ñ, R75
Operation voltage limit
Maximum dissipation power of the thermistor over the ambient temperature ramp:
from -50 to +60°Ñ
from +51 to +80°Ñ
Thermistor power dissipation coefficient at ambient temperature plus (25±10)°Ñ
Maximum allowable ambient temperature
Mean time before failure
Terminals:
wire
screwed
Average storageability time
Mass
Operation conditios:
environment temperature
relative humidity
atmospheric pressure | (68 ± 1)°Ñ
(5 ± 2)°Ñ
less than or equal to 4 sec
at least 1000 kOhm
at least 250 kOhm (R50 ≥0.25 R23)
less than or equal to 0.2 kOhm (R75 ≤0.0002 R23)
38 V
60 mW
40mW
less than or equal to 1.5 mW/°Ñ
+140°Ñ
150 000 h
d0.5 x (13.5±1); (23±1) mm
M3
8 years
no more than 0.15 g
-50…+125°Ñ
(45-80)%
(84,0-106,7) kPa |
ORDER IDENTIFICATIONS
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