Hour Meter Installation

[Jonathan Hirst]

I have a question for the electrical minds out there. I currently use an analog hour meter on my Club Ford similar to what is pictured.

I have it is connected to the +'ve side of the coil, and the -'ve terminal to the chassis, which means it increments when the ignition is on, not necessarily when the engine is running. Not a substantial error but if the ignition is left on for whatever reason, well...


Does anyone have any thoughts on how to refine the recorded time to just receive power when the engine is running? An impulse relay of sorts ?

I do not have any DA on the car.

Any thoughts appreciated.




Thanks - Jonathan

[formulasuper]

On rental aircraft it is connected to an oil pressure sensor, however on some rentals it is connected to the master switch to get every dollar they can.

[sracing]

Cheapest way: You could add a OP (or Fuel pressure sensor swtich) The meter would run through that. Thus, only running when either are at pressure. Longacre 4360 or Longacre 4302. We have both in stock. (You can't use the existing OP sender since without a buffer circuit it will cause an OP error at your meter.

Or could be done with a small 555 and relay circuit to trigger on when ignition pulses are present. Or a small isolator from the OP switch And then shuts off when pulses aren't there. But some work, for the minor error you are currently seeing.

Call if you have questions.

Jim
SR

[R. Pare]

Probably easiest to just run it in series with an oil pressure switch.

[Dee]

Contact aircraft spruce in corona ca. They have a hobbs meter with two wires, one to ground and one gets rapped around any plug wire. This unit only records run time ,it also records highest rpm.
Great unit, i think its twenty bucks or so.
Dave
penske ralt rt-5
p-51

[Daryl DeArman]

Or could be done with a small 555 and relay circuit to trigger on when ignition pulses are present...

Wow flashback to entry level IC Electronics courses and building a J-K flip/flop on a breadboard...thanks. Haven't heard that language in 20+ years!

[rickb99]

.... one to ground and one gets rapped around any plug wire.

Man! I was going to post that as a joke here about 2 hours ago.

How do they avoid a high voltage level pulse taking out the meter??

[sracing]

This is the only one I could find that would work off a spark plug wire. Just like those on a upscale riding lawn mower. $48

http://www.aircraftspruce.com/pages/...h/tinytt2a.php

They have several that would work (as would yours) using a simple pressure switch.

http://www.aircraftspruce.com/catego...ers_hobbs.html

[formulasuper]

Or you could use a vibration powered hour meter. Long ago I rented a Piper Cub with a 65hp engine & no electrical system that used this type.

The Intermatic Vibration DC Hour Meters records running time of machine and vehicles, which vibrate during operation. The automatic mechanism in these meters convert vibrations into energy, which drives the hour meter and minute sweep hand. These meters have a high-sensitivity level, capable of operating from the slight vibration of a moving car. All can withstand an IP20 environmental rating (IP54 with use of gasket).

[sracing]

But then it will run while in the trailer being hauled..

[formulasuper]

But then it will run while in the trailer being hauled..

Ha! True.

[Jonathan Hirst]

This is the only one I could find that would work off a spark plug wire. Just like those on a upscale riding lawn mower. $48

http://www.aircraftspruce.com/pages/...h/tinytt2a.php

They have several that would work (as would yours) using a simple pressure switch.

http://www.aircraftspruce.com/catego...ers_hobbs.html

Thank you for the replies. So those OP Aircraft Spruce sensors close under pressure I presume, the opposite of what I use for my low OP light.

That should work great.

As was mentioned to me offline, I might concern myself more with a counter that tracks the hours between the engine running. Let's see, my son is 6 years old....



Jonathan