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Title: TIM rev counter
Post by: tom70 on July 22, 2007, 11:08:32 PM

Does anyone know if the TIM rev counter need a 5v or 12v pull up for the rev signal ?

My rev counter didn't come with an instruction.

Cheers

Title: Re: TIM rev counter
Post by: [email protected] on July 23, 2007, 08:44:23 AM

Is it meant to be connected to the coil '-' ?
If so 12v will be okay. I'd take a 1K resistor inline with the tacho signal in, and bounce the open end off the + terminal of the battery.

I can't understand why the diodes arent giving the right signal for you?

Title: Re: TIM rev counter
Post by: dnb on July 23, 2007, 12:24:16 PM

If it's supposed to go to a coil -ve, then the counter may well be expecting a high voltage (ie 350v or more) signal caused as the magnetic field breaks down. In this case, the voltage must be duplicated with an inductive pullup - naturally, diode protection should be used to protect the ECU.

Title: Re: TIM rev counter
Post by: [email protected] on July 23, 2007, 01:00:05 PM

In that case the 18V zener diode is reducing the voltage too much for the rev counter.

Title: Re: TIM rev counter
Post by: tom70 on July 23, 2007, 07:28:45 PM

Thanks for the help here.

I have no idea why the diode don't work, the rev counter is just not responding.

Talking about pull up, which of the following connection is correct?

Option 1:
(http://i3.photobucket.com/albums/y74/tony4_00/tacho2.jpg)

Option 2:
(http://i3.photobucket.com/albums/y74/tony4_00/tacho1.jpg)

Sorry about my lack of electronic understanding.

Title: Re: TIM rev counter
Post by: [email protected] on July 23, 2007, 09:28:29 PM

Option 2.

When P259 channel is closed the tacho gets 12v, when the channel is open the voltage drops to zero.

Rob

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Technical => Wiring & Sensors => Topic started by: tom70 on July 22, 2007, 11:08:32 PM