Aim PDM 32, User Manual, Page: 15 / 63

www.aim-sportline.com - PDM 32 User Guide 14
7.1 Power Outputs protections
Every output is protected against:
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over voltage
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under voltage
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short circuit
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over current
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over temperature
Please, refer to the paragraph “
Power Output related channels ” for further information
Every output channel has two related channels showing Status and Current.
The High-Power Output 1 has an internal diode in series
The High-Power Outputs (1,2,3,4) have an internal freewheeling diode protection
7.2 High Power Output 1 Protection diode
H1 output of PDM is a dedicated output protected by a series diode. This diode could be very useful to
power devices that, when activated, can generate a current toward the PDM. Of course, H1 output could
anyway be used as a standard High Side output.
A typical example of a device that needs such a protection is the starter motor. During the starter
activation, a current flow from the PDM output to P1 of Starter. From P1 current goes to GND through the
internal aux solenoid to P4 and then through the main solenoid to P3. During this phase, the internal aux
solenoid closes the main switch of starter, connecting P2 to P4.
The starter motor now is activated and its rotation switches ON the vehicle Engine.
When the engine is ON, PDM out must be disabled. Internal diode block reverse current that would flow
from P4 (shorted to P2) to P1 and finally to PDM out.