Relay Control

Discussion and support for MoTeC's previous generation ECUs.

Relay Control

Postby killerbee on Tue Mar 30, 2010 2:02 pm

How do I configure the m800 to control a relay using an AUX output (or any other output for that matter) ? The goal is to switch a 2nd fuel pump on/off above/below a certain rpm. The canned configurations do not seem to be appropriate and I would rather ask then waste time messing about. Also is there a way to avoid switching the realy off/on quickly, i.e. anti-bounce ?

Any help is appreciated.
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Re: Relay Control

Postby 20B on Tue Mar 30, 2010 7:28 pm

You would simply need to set the aux output as a user defined table with one axis being rpm and the other being duty cycle (100% is on and 0% is off). The ecu will not control the relay for bounce, rather you will need a relay specifically purchased with these parameters built in but I wouldnt think this is an issue really.
Alternatively you could drive the fuel pump via pulse width modulation with the new DHB controller (more money), that way you can run the pump at variable speed with no inrush type current problems.
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Re: Relay Control

Postby Martin on Tue Mar 30, 2010 8:02 pm

20B is right, use a aux table to drive your relay with the axis you decide on


Bounce will not be a problem, use the hysteresis function. Hysteresis = 1

when hysteresis = 1 then table MUST read 100 to turn on and must read 0 or less to turn off.
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