High-voltage PTC heater
Electrical system
47
Introduction of smart fortwo electric drive (3rd Generation) • Model Series 451
The high-voltage PTC heater consists of a heating
element with PTC ceramic modules, corrugated
fins and a control unit with control electronics. In
the PTC ceramic modules, the regulated current
from the control electronics is converted into
heat. Aluminium fins are in direct contact with the
PTC ceramic modules and transfer the heat to the
air.
For better control, the surface area of the high-
voltage PTC heater is divided into 4 independently
controllable sections.
The control unit of the high-voltage PTC heater
receives the output request for the individual PTC
sections from the drivetrain control unit and
actuates the individual output stages of the power
electronics via PWM signals.
In order to maintain a uniform load on the on-
board electrical system, the stages are operated
with a PWM offset.
P83.70-5432-00
1 Air
conditioner
housing
2 High-voltage
connection
3
On-board electrical system/CAN connector
N33/5 High-voltage PTC heater
