I've been thinking about this for a while. Everyone always talks about how many hours are on their tubes. It takes X amount of hours for them to sound their best etc. Same for PIO coupling caps and some filter caps. Does anyone make or has anyone implemented a simple little hour meter that counts time when the B+ is applied? Something similar to what's seen on a tractor or industrial engine.
I've never seen one for such an application.
I've never seen one for such an application.
you can get a "Hobb's Meter" on EBay -- used to track the number of hours on your Continental 500 HP Twins.
An externally hosted image should be here but it was not working when we last tested it.
I have implemented a PIC based one using the non-volatile flashram in the PIC. It counts minuits using an error resistant rolling code from when it was first powered up and cannot be reset. It is good for 16 million minuits. Not intended for audio use it was origanally a kind of spy chip to protect my former employer against rouge warranty claims on electronic ignition systems we built. The code never got used in anger as we went into liquidation soon after i cobbled it together but i still have it. It displays the power on time on an LCD at switch on, then shows a company splash screen followed by execution of whatever code ( if any ) that may be of use elsewere. The timer uses internal interupts but no I.O so the chip can be put to other tasks when running. If i implement it into a more useful form EG volume/source selection, remote ect I'll let you all know and maybe post the code somewere on DIYAudio.com. I bet sombody else has done it elsewere tho....
Leigh
Leigh
I have an old Panasonic VCR (AG6810S) that has a hour meter in the front. It is manufactured by Fuji Ceramics, type is TM2 and counts up to 5000 hours. Looks like a tiny thermometer, a gap is moving in a quicksilver bar. The part is plugged in a socket (1 1/2" pin distance) and I heard somewhere that such components can be reversed so they start counting over.
normally you run them to the end then turn them around.
you can hurry them up on a bench supply with some extra current but don't go over the top. 10x normal speed should be safe. If you have a few try 30 times.
The one I saw was for the bearing replacment interval on a gyro.
the gap has an electrolyte in it, the current pushes mercury ions through the electrolyte.
you can hurry them up on a bench supply with some extra current but don't go over the top. 10x normal speed should be safe. If you have a few try 30 times.
The one I saw was for the bearing replacment interval on a gyro.
the gap has an electrolyte in it, the current pushes mercury ions through the electrolyte.
I use a curtis instruments LCD type, mighty small, non invasive with reset and can be juiced from the 6.3V heater line. Good component stockists like Farnell should list'em.
see http://www.curtisinst.com/#
A view of the LCD Curtis hr meter and LED general Voltmeter by Datel encl
rich
see http://www.curtisinst.com/#
A view of the LCD Curtis hr meter and LED general Voltmeter by Datel encl
rich
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Lascar do a neat single hole mounted LCD unit called the EMC 1500.
They also have distributors in North America and Canada as well as UK and Europe. The unit will run from any dc voltage 5 - 27V.
http://www.lascarelectronics.com/temperaturedatalogger.php?datalogger=112
They also have distributors in North America and Canada as well as UK and Europe. The unit will run from any dc voltage 5 - 27V.
http://www.lascarelectronics.com/temperaturedatalogger.php?datalogger=112
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