ADVICE NEEDED - Contactor Economiser Circuit

Other Hardware Product Design
1

Hey guys! I was planning on doing a fun lil project though not sure where to start. I think this could be done without an arduino though not sure. A schematic or block diagram would help allot!

Objectives
-Design a circuit for an efficient economizer that will operate between 9-32V.
-Peak and hold
-Provide a constant current source.
-Use Digikey, LCSC, and/or Mouser, electronics distributors for parts. -
The PCB must fit around the contactor in a small, confined space. It must have a very small form factor.
-Have the inputs only be power and ground for minimal wiring.

Contactors
-Contactor 1: 2272229-1 Minimum 550ma pull in and 170ma hold MINIMUM, may vary from unit to unit
-Contactor 2: 2138622-1 Minimum 333ma pull in and 160ma hold, these are minimums and may vary from unit to unit
-Both contactors:
25ms pull in time minimum
Operating voltage for input circuit is 9-32v, 9v min is contactor maximum pull in voltage 32v is highest expected supply voltage
Must regulate current - not just PWM

Background information
Contactors used in the car are galvanically isolated and are only activated with the force of a magnetic field pulling the switch closed. The magnetic force is generated when current (not voltage!) flows through a coil of wire. Often to activate a contactor the inrush current is fairly high, but once activated the current to sustain the state is much lower. Without an economizer the contactors will dissipate power as heat, weakening the magnetic force and resulting in a flickering on/off state. On the car all boards are designed to handle between 9-32V, the contactor economizer is no exception. There will be two contactors used to switch the high and low side of the battery pack.

2

Have two MOSFETs and set of resistors for the turn-on and the hold states.

3

If possible, would you be able to give a schamatic or a block diagram of this? I'm sorry I'm not knowledgable on designing as its my first go at this stuff.

4

You're basically asking for someone to design an industrial product for you so you can build it as a kit?

I'll do it for $1500: it's not that hard.

Take away the requirement for constant current and it's identical to something I did over the summer. A Nano and a motor driver is all you need.

1 Like
5

This might help you as it appears destined for a vehicle.

  1. STMicroelectronics Application Note AN2689:
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  2. Analog Devices: Automotive Electronics Design:
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  3. Diodes Incorporated: Transient Voltage Suppression in Automotive:
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  4. AEC-100 Standards Webinar:
    This webinar from Monolithic Power Systems provides a detailed overview of AEC standards, essential for understanding automotive electronics requirements.
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  5. Understanding Automotive Electronics, An Engineering Perspective by William B. Ribbens:
    This comprehensive book offers an in-depth look into automotive electronics from an engineering perspective, making it an invaluable resource.
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6

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