Tested Gauge Clusters

[BillsGU]

The first couple of times I hooked up the oscilloscope the square wave was about 1.5 -2.0 volts at the top of nine volts dc. That is why I said a 9v bias. Today my scope shows a square wave as just a 7-8 volt wave (peak to peak) to earth. I have no idea why it has done this as I haven't changed the parameters. I am still struggling to understand the chinese instruction manual.

Edit: Maybe early on, I measured just across the resistor and not from the yellow black to earth??

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.

[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.

[NissanGQ4.2]

Not sure if your interested: https://www.facebook.com/photo.php?f...type=1&theater

[mudnut]

Thanks, I don't have FB, so I'll get Mrs mudsane to check it out.

[mudnut]

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.

[Bloodyaussie]

Nearly finished. I still haven't finished 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 !!!!

[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.

[mudnut]

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.

[mudnut]

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

[NissanGQ4.2]

I need to get good, clear pictures of the front and back of all the different styles and models of the GQ clusters. TB42, TB42E, TD42, RD28, RB30, Turbo, Autos and Manual transmissions etc.

So, If you have a spare cluster, or have a need to remove your cluster for any reason, please take some shots and post them up for me.

Do you still need pics mate?

When I get a chance I have a TB42E Auto cluster I can pull out