Upstaging Paul's oddball question. Q? for tach and alternator aficionados

[KWKloeber]

Ok, so on the new LCD Hour Meter/Tach combos, the HM is advanced via the tach signal, not just by being powered by 12v (this results in true "engine run" hours, instead of "tach powered-up" hours.)

So there's no way to advance a replacement tach to match the engine hours.     or is there?  ....maybe......   

Would, seeing that the alternator sends a 12v A/C signal, would hooking the tach to a step-down 120 vac to 12 vac wall-plug-in transformer advance the hour meter?  The current in the tach signal wire is low, and I see 12 vac wall-plug transformers that can supply up to 5 amps AC.

Does anyone have any knowledge (that would make you an aficionado) or experience with this?

How's that for an oddball?   

Ken

[Noah]

Just testing the new image uploader...

[KWKloeber]

Faraday cage or not, that's just plain wrong! 

[Stu Jackson]

>>>>>>>>>>>>>
>>>>>>>>>>>>>

So there's no way to advance a replacement tach to match the engine hours.     or is there?  ....maybe......  >>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>

Couldn't one just hook up the HM to any 12V source and leave it on as long as you like or is necessary?  2,000 hours is about 3 months, though!

All the Seaward cockpit panel manuals show the hook up of the combined tach hour meter.  As far as I know, they are separate signals, and the HM runs whenever there is power applied, regardless of whether the engine is actually running or not.

What I don't know is how one would try to save time by making it go faster than hour-for-hour.  Kinda like those old cassette tape dual decks that you could run at double speed to record dups twice as fast.

[KWKloeber]

 I love you Stu, but I think you didn't read my post. Or at least all of it before jumping in. Or on? ;-)

I clearly stated that, the LCD digital hour meter/ Tachs DO NOT  Advance by merely applying 12 volts.  The hourmeter advances only when it receives the alternator tach signal.  I also stated that, this is because they are set up to accurately measure engine running time, not merely 12 volt energized time.

The desire is to advance the hourmeter, not run anything faster than it normally would be.  The thought/questionwas, since the alternator signal is 12 V AC, why would a 12 V AC transformer work?

Capisce?

k

[Stu Jackson]

Ken, I just edited my post before i read yours.  Perhaps you could try again.

[mainesail]

Alternatively buy the less expensive tach without an hour meter, and install a Hobbs meter near or in the engine room. I can't even begin to count the number of tachometers I have replaced because "my hour meter quit but the tach is fine". Oh and just be glad you can drop in a $60.00 tach vs. a $650.00 Yanmar/VDO that is a proprietary fit/design...

[KWKloeber]

Ken, I just edited my post before i read yours.  Perhaps you could try again.

Stu,

Non comprendo, Senor. 
I see your post, but "try again???"  I'll restate it differently (4 ways below)

Couldn't one just hook up the HM to any 12V source and leave it on as long as you like or is necessary?

1). NO! One cannot do that.  Well one could, but the hour meter will NOT advance.  Nada.  Zip. Niet.

2). They don't work the same as the mechanical HMs.

3). They advance ONLY when receiving the alt signal.

4). New tach, different technology.



More clearly stated now? (Below I explained (one reason) WHY they have them operate that way)

k

[Stu Jackson]

Ok, so on the new LCD Hour Meter/Tach combos, the HM is advanced via the tach signal, not just by being powered by 12v (this results in true "engine run" hours, instead of "tach powered-up" hours.)

My apologies.  I was wrong.  Sorry.

[KWKloeber]

Aaaaha. I see now. It's all good.
should have emphasized "LCD"

k

[britinusa]

Does it require an AC signal, or just a Hi Lo varying signal?

Makes think of another use of the old Bell Buzzer!

If it's just an intermittent signal, then the buzzer should do it.

Or MacGyver it - Attach an motor turned in a drill chuck (assuming the drill isn't destroyed while trying out the engine start sequence  )

Paul

[KWKloeber]

Paul,

In a word, 

It may be simply a 0v /+12v pulse, not -12v /+12v.  My background is CE, not EE!   Electronics baffle me.

I's hate to ruin a new $90 tach trying it out w/a 12vac transformer and ruin my day.  Surely there must be some sparks person in he group that knows?!?   

BTW, speaking of engine start sequence.  Peggy does know that you don't have an A-4 ignition that could be cobbed into a makeshift AED, right?  Better have one on standby when you do this.

ken

[J_Sail]

Alternatively buy the less expensive tach without an hour meter, and install a Hobbs meter near or in the engine room. I can't even begin to count the number of tachometers I have replaced because "my hour meter quit but the tach is fine". Oh and just be glad you can drop in a $60.00 tach vs. a $650.00 Yanmar/VDO that is a proprietary fit/design...

Any recommendation on a Hobbs meter? I am facing exactly the "$650.00 Yanmar/VDO" problem on a friend's Jeanneau, where the hour meter portion died (sorry - that's not a C34 issue, but the overall topic is relevant). I may tear it apart to fix, but figured a Hobbs meter is a good solution. I'd like one that's surface mount in the engine compartment and am having trouble finding that mounting configuration. The same situation presumably applies to C34s.

ALSO - I see several battery operated ones on Amazon that claim to not need wiring, but instead rely on sensing the engine vibration. Reviews are mixed and I worry that they are unreliable. Anybody have experience with them?

Jeremy

[KWKloeber]

Alternatively buy the less expensive tach without an hour meter, and install a Hobbs meter near or in the engine room. I can't even begin to count the number of tachometers I have replaced because "my hour meter quit but the tach is fine". Oh and just be glad you can drop in a $60.00 tach vs. a $650.00 Yanmar/VDO that is a proprietary fit/design...

Thanks Rod, and good idea -- had already been discussed. 

It's kinda like AIO printers -- why throw away three things when one craps out.  Although thet'e so cheap now you an afford to.

The fuel gauge is already being moved to one "like yours" to make way for an oil pressure.  Build the boats/panels cheap, cheap, cheap with no oil pressure gauge.  Makes no sense.

Thanks,
Ken

Still begs the question, though --- will any AC source work?  So I just put the question to VDO, V-3, and Faria.  We'll see...

[britinusa]

Our Tach Engine Hours meter stopped long before we purchased Eximius.

During the Engine Harness replacement, I also installed all new instruments but didn't want to spring for the Tach that included the hour meter.

So I installed a $13 hour meter
Docooler® Tachometer Tach Hour Meter for car
by Docooler
Link: http://a.co/1Hzn1OZ

It's installed at the Nav Station.

Paul