Wideband guage for Hydra ECU
 

Anyone connect an A/F meter to their Hydra ECU? Is it as simple as connecting power, ground and signal?

not nearly that easy. maybe not even possible. you need a signal from the wideband controller (which is internal to the hydra) to send to the gauge/meter.

you'd have to set up a PWM output to provide that signal based on AFR and then convert it to a straight voltage to match the input of your meter.

Matt

plus the sensor that the hydra uses (for some reason) is way different than the other available sensors......

I read this on mdac.com:

"A user defined PWM signal can also be used as a data and power source for the MDAC GP-meter 1.0. The display data is 0.256 times the duty cycle percentage. For example, to show AFR, a programmable ECU user defined PWM output would be programmed to output a 57% duty cycle at AFR = 14.7. The MDAC GP-meter 1.0 would output '14.7' based on the above equation."

I'm such a dumb-ass that I can't think of how I would take an Autometer gauge that has a range of 0~5V and make that conversion.

could someone enlighten me on the actual purpose of a A/F gauge? i dont mean widebands, i mean the gauge itself.

well it its a NB o2 to make pretty lights :ugh2:

RC filter. it'll filter out the frequency component and leave you with avg voltage. for example. 50% duty cycle means you're at 5V half the time. the average of that would be 2.5V.

it works because the C (capacitor) is essentially a little battery with a fast discharge rate. as the duty cycle increases, there's more on-time to charge up the cap and give it a higher charge voltage.

http://controls.ame.nd.edu/microcont...in/node40.html shows you how to build it. simple. probably can power the +12 off Vbatt depending on how tolerant the opamp is.

Matt