Battery knowledge · High-voltage and functional safety
Contactor coil economiser
A circuit that drives a contactor coil hard to close it, then cuts the power to the much lower level needed to hold it shut, often by pulse-width modulation. A typical 500 A contactor holds on under 2 W at 12 V; the saving matters for heat and for the low-voltage supply when several contactors stay closed for hours.
- Also called
- coil economizer, economiser, PWM coil drive
Example
High-voltage and functional safety: an example situation
Normal-operation current limits do not demonstrate correct contactor behavior under a welded-contact or sensor fault.
Read Contactor coil economiser alongside Auxiliary battery in this context. The small 12 V or 48 V battery in an electric vehicle that powers the controllers, lights and locks and wakes the BMS, kept charged from the high-voltage pack through a DC/DC converter. A flat auxiliary battery immobilises the car however full the main pack is.
Use in Lemonergy
Relate protection to faults, detection and response.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- ISO 26262-1:2018 — Road vehicles — Functional safety — Part 1: Vocabulary
International Organization for Standardization · 2018
Topic background · Scope and terminology of automotive electrical/electronic functional safety. The catalogue is not the full standard.