Terratrip probe technical question...

[Kaptainballistik]

Ok, does the Terratrip probe out put a square sine wave or a unfiltered output? (If you dont understand that question, You probably dont know the answer...)

Trying to trigger a Tach to act as a speedo...

Also, can The terratrip handle another load off the probe?

[brendan]

Originally Posted by Kaptainballistik

Ok, does the Terratrip probe out put a square sine wave or a unfiltered output? (If you dont understand that question, You probably dont know the answer...)

Trying to trigger a Tach to act as a speedo...

Also, can The terratrip handle another load off the probe?

I would think they are square wave. or close to due to them being a switch. i have attached a data sheet of some probe but this might be different to your one. Sorry can't be much more help with out testing it my self or finding a better data sheet

Some data sheet

[Kaptainballistik]

That should do.... I havent got an Ociliscpe to test it !

[bob moore]

Originally Posted by Kaptainballistik

Ok, does the Terratrip probe out put a square sine wave or a unfiltered output? (If you dont understand that question, You probably dont know the answer...)

Well, I don't understand the question. I know what a square wave looks like, and I know what a sine wave looks like. But a "square sine" wave? Are you sure you've got the question right?

Despite my technical shortcomings, I think I know the answer. I think you get a series of positive pulses. I can't see any reason why the signal would go negative, so you'd get neither a balanced square wave nor a balanced sine wave.

Originally Posted by Kaptainballistik

Ociliscpe

Over here in Kenya, we call them oscilloscopes ..........

[Kaptainballistik]

Not enough sleep...And a Rx2 still not ready.

Well, thats my excuse...... So what bob was saying........

[WAC Secretary]

It's a square wave, but it doesn't swing all the way to both ends of the supply voltage.

The probe is connected with resistors in series to both sides of the supply, so it varies the resulting voltage divider from about 2V to 8V. (Sorry, bit technical) Basically the probe is an electronic switch, it turns on and off cleanly, square wave.

Why try using a tacho as a speedo? It's not likely you'll be able to calibrate it very well.

Still, a tacho is just a frequency meter. I think you'd want to connect the probe + to 12V, and the probe - to a 1k resistor, with the other side of the resistor to ground (- side of the battery). Connect the tacho input to the probe -/resistor junction. You might have to fiddle around with the resistor value and/or put it on the + side depending on the internal circuit in the tacho to get it to work. You'll want the usual 4/5 pickup points per wheel revolution.

Many tacho's have an adjustment on the back that might help make the dial scale mean something useful.

I doubt you'll be able to run the terratrip and tacho off the one probe due to the extra loading of the tacho. They are meant for quite nasty, very low impedance signals in the ignition system.

[brendan]

If you need an electronc speedo and willing to play around a little i have one out of the corsair let me know and i will bring it along to BRM

[Kaptainballistik]

will play! (Its fit a bike speedo time..............)