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In-Car Navigation System

System View | Block Diagram
Protection Area Illustration (click to open larger image in new window)
  1. Antenna
  2. Backlight Heater
  3. Battery
  4. Buttons
  5. CD / DVD Player
  6. Circuit Board
  7. Data Line Port
  8. Hard Disk Drive
  9. I/O Power Port
  10. Memory Card Slot
  11. Power-line
  12. RF Tuner
  13. USB 2.0 port


I/O Power Port I/O Port Circuit Board RF tuner Hard Disk Drive data line Data Line Antenna Antenna Hard Disk Drive Memory Card Slot Memory Card Slot Backlight Heater USB USB Power Line Battery Battery Buttons/Keyboard Buttons/Keyboard CD/DVD Player CD/DVD Player

Backlight Heater Protection

Problem: Thermal Runaway

If the control circuitry fails to turn off the element, the current flowing through the heating element can increase and lead to thermal runaway.
 

Solution: PolySwitch devices

The PolySwitch resettable device is thermally linked to the the LCD (Liquid Crystal Display) glass. It will “thermally trip” thus reducing the current flowing through the heating element.

 

Read more about the Raychem Surface-mount (SMD) PolySwitch devices.

Applicable Products: decaSMD, nanoSMD, microSMD, miniSMD, SMD, SMDH, AHS, ASMD.
Download SMD Datasheet - (pdf 440KB)
Agency Recognition: UL E74889, TÜV R9872049, R9872048, R2172061, CSA 078165_C_000. Please note that all SMD, mini SMD, nanoSMD, ASMD and AHS PolySwitch devices have been tested to meet the AECQ200 specification.
 

Read more about Raychem Radial-leaded PolySwitch devices.

Applicable Products: RXEF, RTEF, RUEF, RUSBF, RHEF, RGEF, AGRF, AHRF, BBRF.
Download Radial-leaded PolySwitch Datasheet - (pdf 707 KB)
Agency recognitions: UL E74889, CSA 078165_C_000, TÜV. Please note that all AHRF and AGRF PolySwitch devices have been tested to meet the AECQ200 specification.

 

Circuit Diagram / Schematic
 

Application Notes:

• LCD application note - (pdf 36 KB)
• Fundamentals of PolySwitch Overcurrent and Overtemperature Devices In-Depth - (pdf 169KB)
• Selection Guide for PolySwitch Devices and Technology Summary - (pdf 1,550KB)
 

Competitor Cross-reference

Cross-reference competitor products

Block Diagram