Engine running detection

[Joshiii]

HI Guys

I am looking for a way to monitor if a stationary engine (i.e Lister water pump) is running or not. These engines have no electrical except the coil to provide spark with an on/off button to interrupt the coil. I have a gsm commander that can measure voltage input or open/close state and send sms regarding the programming of said input.

I have thought about a magnet running on the fly wheel triggering a reed switch or infra red

Please assist with a circuit that will help me solve the problem

Thank you

 

[tunedwolf]

If I were designing this, I would be wanting a little more payback for the effort. I would be looking at perhaps retro-fitting a switched reluctance sensor to the flywheel and garnering things like engine rpm so that actual gpm can be calculated, fuel requirements can be more accurately estimated etc, possibly add some temperature sensing too. If you already have a radio link of some sort, even if it is gsm/sms, why not include that information too. Craft your information packets in such a way as to be able to directly import the data into a spreadsheet for example and you can plot how much it's costing to run the pump, at what points in the year it costs more, when maintenance is likely needed etc. It could help you mitigate the need for it in the end, or at least help you reduce the running costs of it. I would just use a small microcontroller and some analog signal condtioning to process the sensors and couple the electronics with a battery and charger driven from the engine or perhaps even a solar charger depending on conditions

 

[Joshiii]

HI Tunedwolf
I do not need this info, all that is required is an idea how to monitor a small stationary engine a couple of kilometers away from my house on a dam massive farm if it is running, these engines run until the petrol (2 Liters) is finished and the motor cuts out anyway, (hand crank start involved) but what happens is sometimes you start and then leave and the motor dies, resulting in no water for the animals, I am already measuring water levels in the tanks so that is not necessary. The gsm commander already cuts the motor if tanks are full.
I can either add a small motor to the fan belt to provide 12v and measure it that way or reed switch with magnets on the flywheel or measure induction on the spark plug lead.

 

[tunedwolf]

Ok, just use a simple pressure switch on the pump outlet (pressure side) then, that way you get the benefit of knowing that it's not pumping, rather than just that the engine isn't running. Either case will be bad for the animals

 

[Les Jones]

If you can access the connection to the contact breaker then use this signal to trigger a re triggerable monostable. The pulse from the contact breaker will be a couple of hundred volts so you will need to reduce it's amplitude with a potential divider using fairly high value resistors. (Try a 470 K and a 12K) I assume it will be a flywheel type magneto. If so they sometimes bring the contact breaker out to a switch that shorts it to earth for stopping the engine.

Les.

 

[rumpfy]

I'm with Tuned Wolf.
Measuring water flow by either pressure or flow is the way to go. Depending on your exact system, the pump could be running but delivering no water. If this happens with a centrifugal pump, it will overheat. Alternatively, if the pump is helical rotor, the pump will not like running dry.

 

[MikeMl]

How about just measuring temperature of the head or detecting oil pressure? Either sensor can be just a simple switch closure...

 

[Joshiii]

To keep matters simplified I agree, rather measure engine temp and maybe incorporating flow to make sure pump is not running dry.

 

[Ian Rogers]

Engine hour meters have a motion sensor in to monitor exactly that..

 

[Joshiii]

this motor is a very old Lister engine without any meters or indicators

 

[Ian Rogers]

this motor is a very old Lister engine without any meters or indicators

Engine hour meters are dead cheap... They just sit on the engine and when it runs, it counts the hours it has run!!



This one is expensive, but I have seen cheaper ones....

 

[Externet]

The concern is animals must have water.
Install a flow lever switch at a water discharge hose end flap to turn on a red laser pointer aimed to your house window [or radio signal] when there is no flow, to signal no-pumping.
Like ----> https://www.spiraxsarco.com/Resources/Pages/Steam-Engineering-Tutorials/Images/12/3/fig_12_3_5.gif

If you still insist on monitoring only the engine running, install an engine oil pressure switch to activate whatever signalling you prefer.
Like ----> https://www.hdforums.com/forum/atta...l-pressure-switch-help-ps-135_zpse79d42de.jpg

 

[shortbus=]

Only problem with an oil pressure switch is these engines have no oil pressure. They use a "dipper" to throw the oil around in the crankcase. like a small push lawnmower does.

 

[Externet]

It smelled like that with just a 2 litre fuel tank.
Then use a vane/lever at the exhaust gases flow to pull a switch on. Or at any cooling fan air flow. If it has a speed governor, that can switch something too.

And check for any useable voltage across the terminals of its on/off switch when it is running.

 

[Tony Stewart]

To make it a reliable sensor, all causes of potential failure from the environment must be considered, like automotive. Waterproofing, heat , rust, rodents eating PVC wire insulation, insects clogging exposed sensors.

One novel approach is an electret microphone near the engine and detect the exhaust noise envelope to drive a transistor switch with pullup and filtering ambient low level noises. This could be a quasi-peak or R-C-diode series detection method that pumps up a larger capacitor to drive a FET switch with open drain & pullup R to the GSM transponder logic input. Time constants of >> 1 second could reject ambient noise bursts. This could make a solution with common parts with waterproofing. 5V from GSM can power the mic. with low current. It can also all be done with CMOS. Inverters with linear gain & hysteresis.

 

[Externet]

Like it !
Audio/vibration sensing = automotive knock sensor at any wreck yard for near $0. Some circuitry to follow it.

----> https://images.esellerpro.com/106/I/324/6/knock_sensor.jpg

A klixon thermal switch could also work great, and cannot be simpler, no circuitry needed. Mounted on a plate heated by the exhaust fumes to isolate it from vibration.

----> https://duckduckgo.com/?q=klixon+switch&t=canonical&ia=images

 

[shortbus=]

A hall sensor near the flywheel magnets would probably work too. Or from a junk yard a crank or cam position sender. The knock sensor is looking for a certain frequency, not sure a air cooled engine would create that frequency if running correctly.

 

[Externet]

Automotive knock sensors are pure microphones. Discerning noise from knocking noise is done by the 'processing' circuitry in the ECU.

A Hall sensor is yes, another valid way.

 

[MaxHeadRoom78]

The automotive timing sensor is nothing more that a hall effect (flywheel) gear tooth sensor, I have used the GT1 version sold by Micro Switch/Honeywell avail from Digikey if an auto wrecker does not have.
Max.

 

[shortbus=]

Don't know about the newer ones they may all be hall's now. But the older ones, GM at least, used a magnet and wire coil, like a guitar pickup.