12 volt Hour Meter
 

My new ENM resettable hour meter arrived a few days ago. This new hour meter operates on 4 to 60 volts AC or DC. The reset feature will allow me to zero the meter when it's time to re-tube my power amplifiers. I will operate the meter using one of the 12 volt trigger outputs on the MC2301. My older 120 volt hour meter does not have a reset feature, so this new hour meter will be more useful. It's physical dimensions are identical to the 120 volt hour meter so I was able to use the same Radio Shack PVC work box for my new hour meter. I just had to add the normally-open momentary contact push button to be able to wire and use the reset feature. I used a six foot mono mini plug cable, cutting off one mini plug and using that end of the cable to attach the wires to the meter terminals. I tested the meter and the reset function using a 9 volt battery. It works perfectly. Since my pair of MC2301's now have just over 600 hours on them, I will keep the hour meter connected to the 9 volt battery until the time equals the hours on the amplifiers. After that I will plug the hour meter mini jack into one of the amp's triggered output jacks. This makes it simple to accurately keep track of the hours on power tubes.


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That's cool. You would thing these devices would have some internal way of tracking tube usage too.

Dan... Nicely Done, as always! :ok:

Quality job Dan and modeling mine after yours.:thumbsup: Thank-you.

I may have gotten a smaller project enclosure and may return it for a larger one now that the button will be incorporated.

Just for search purposes, the 6v resettable ENM part # is?

Happy Holidays Folks,

Bob

Bob.......The ENM product number is T44F65C. For your reference, the meter is EEPROM based with no battery necessary and operates on 4 to 60 volts AC/DC.

You can barely see it in this photo, but I used a small rubber grommet to pass the mini plug cable through the side of the box, and tied a knot in the cable to keep the cable from being pulled and straining the connections inside. I crimped #14 female terminals on the wires to the meter and soldered the wires to the switch terminals. The N.O. Momentary Contact pushbutton switch is available at Radio Shack, too.


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Good Job Dan. :thumbsup::thumbsup:

Rob.......Thank you. I think so, too. ;)

Call it like I see it. :D

Bob.......The ENM hour meter now has 365.6 hours on as I continue to let it acquire hours to eventually match my MC2301's hours. Then I will plug it into the Trigger Out on one of the 2301's. After that it will turn on and off with the power amplifiers and keep track of my tube's hours.

This hour meter must have an extremely low milliamp draw because I am still on the original 9V battery I connected it to when I began logging hours on the meter.


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Looking good Dan. I'll admit, mine is still in the construction stage; I'll get there one day.

Happy New Year,

Bob