Printable View
OK - the second reading makes more sense. You can't use a (normal 240 volt) scope like you use a multi meter. You can't just poke it into a circuit and measure across components because the negative clip is earth. All of your measurements must be wrt earth.Quote:
Originally Posted by mudnut
Got the tacho signal working today. I can adjust the TB42E tacho from around 1000 up to about 5800 rpm. I have been a bit slack with setting up the speedo properly as I have decided to make the unit detachable so that it can be fitted to the sender under the car as well.
Not sure if your interested: https://www.facebook.com/photo.php?f...type=1&theater
Thanks, I don't have FB, so I'll get Mrs mudsane to check it out.
Nearly finished. I still haven't completed the speedo drive unit as such, but I have all the gauges working. All that is needed to drive the tacho is a 555 timer with a couple of pots to balance the voltages to get a wide range of output frequencies with out being limited to fixed frequencies from just switching different capacitors. The whole unit looks shoddy as I have expanded on the original idea. Hopefully, I'll bring it to the next meet up and I can test a heap of clusters.
Looking good !!!!Quote:
Originally Posted by mudnut
Came across some simple circuits to produce low voltage AC sine waves to run the speedo. Had time to have a bit of a play with another 555 timer chip on the bread board and got a low voltage output that runs the speedo up about 40kph. After about 116Hz, the Variable Resistor/ capacitor circuit freaks out and the chips output drops enough to be unable to drive the speedo. Have tried a few different capacitors , but none work too well. I have found a more robust circuit, and will order some more components this week.
I spent some time mucking around with a 555 timer and a couple of small transistors on the breadboard today, and have finally got a simple signal generator working. The signal is able to be easily adjusted, then fine tuned, so I am very happy with it. I have decided to remove the tacho signal box from the test bench. I will combine it with the speedo output in a small box, powered by a 9 volt battery. That way I can throw the unit in the Patrol, for any meet ups.
I've been a bit slack, but I had a bit of time inside, because of the rain, so I finished off the speedo signal generator.
I had to remove from the tacho generator from the box as the AC speedo signal was feeding back through the -ve wire.
I will make a separate unit for the tacho. All I need to do is extend the cable so it plugs in, under the vehicle. I will also make some leads that plug in behind the dash.
My 'third arm' is also shown in the picture. I used the base and flexible arm from an old desk lamp. I will replace the G clamp with a spring loaded clip, when I get around to it
Do you still need pics mate?Quote:
Originally Posted by mudnut
When I get a chance I have a TB42E Auto cluster I can pull out