We would like to replace automotive starter relay with N-MOS.
And the power source for automotive starter is from battery.
So the startup voltage would be 6~16V.(typical)
the relay steady current is 15A, the inrush current would up to 80A

Does any body have this experience to replace starter relay with N-MOS?

And for N-MOS gate driver is also a problem because Vin voltage varies.

 

starters for cars typicly run much more current than just 80 amps when starting. I have seen 250 amps as not too unusual. this combined with the inductive load of the starter motor might make this dificult. high compression cars draw much more current when starting.

 

"ibtl" .......

 

To use an N-MOSFET as a high-side switch you will need to use a bootstrap gate driver circuit since the gate must be at least 10V above the source voltage to be fully turned on. You will also need a large diode from the switch output to ground (anode-gnd) to absorb the high transient inductive current when the switch turns off.

 

I sense a TOS violation heading this threds way.

 

I don't think the mods will have to stop this. The basic idea is so impractical that it will die of its own.

 

He said the relay, not the starter solenoid or the starter itself. In other words it could be done and therefore this thread needs to be closed.

 

The owners of All About Circuits has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

This thread is against the AAC forum rules, Chapter 6, as seen here:

6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

• Any kind of over-unity devices and systems
• Automotive modifications
• Devices designed to electrocute or shock another person
• LEDs to mains
• Phone jammers
• Rail guns and high-energy projectile devices
• Transformer-less power supplies

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Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

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http://forum.allaboutcircuits.com/showthread.php?t=54400

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