Need a circuit for a voltage switch

[Roger Mole]

Made another small step today. I've been working on the new panel for the last few days so this little device went onto the back burner.

savpanel26.jpg

But last night I made up the connections to the flying leads to connect it to the outside world - 12V power and earth, input from rev counter and output to hour meter earth.

savpanel27.jpg

This morning it passed its first test - connecting it for the first time to a 12V battery and here's what happened.

savpanel28.jpg

A little red light came on on the processor. I was greatly relieved that it didn't start smoking and fry itself because I'd messed up my connection layout but I obviously won't know that it's actually working until it's connected up and the engine is run. Hopefully that should be in the next couple of days because I've now got to make up my new radio and transponder wiring looms and get the new panel ready to fit into place.

[Roger Mole]

Coming in here by way of conclusion on this thread in case anyone else is interested in going this route. I set my 'on' trigger to 3200 rpm and my 'off' to 1600. I'm now getting readings on my hobbs that roughly conform to 'brakes off brakes on', just a bit under actually and I'm happy with that as time doesn't start clicking away as soon as I turn the master on and I can warm my engine up (yesterday 7 minutes even on a hot day) without the same happening. So thanks Sean, good job and mission accomplished.

Yesterday was the first time that I've flown the Savannah with its new TQ-KRT2 8.33khz radio and TQ-KTX2 transponder. I have to fly up to La Rochelle to get the installation signed off which you have to do here and every six years thereafter but I wanted to do a check with Bergerac 'just in case'. It all went OK so I can now arrange the La Rochelle flight and I'll finally be legal to fly into the UK again. Looking forward to it as it's been 3 years.

[Antoni]

On topic and also a shameless plug:

https://afors.com/aircraftView/47093

I didn't know what I had salted away until today. Airspeed operated flight timer instrument.

[Sean Dougan]

Oh excellent, glad to see it's working for you, Roger. Actually looks quite a tidy job on the veroboard there.
The instrument panel is real nice. A proper job on a well thought out layout.

Apologies for only getting back to this now, but had a few dark months where things were really getting on me. Mostly all sorted now but I still have a broken C42 to fix after a renter belted a wing off a windsock pole just to add icing on the mouldy cake. I was under pressure to get the thing done by the end of next week but after finding a few more issues hidden under the skins that's not going to happen, so meh.