Automatic on/off switch for Active electronics

[Steve Conner]

Thanks for the heads up, Steve! Keith McMillen makes some amazing stuff. I can feel my wallet emptying out just looking at it.

[Steve A.]

Thanks for the heads up, Steve! Keith McMillen makes some amazing stuff. I can feel my wallet emptying out just looking at it.

I never could justify paying $30 for something that didn't do that much more than a $5 battery tester, but when GC had a Keith McMillen Batt-O-Meter on clearance for $20 I pulled the trigger. When you look at the price of 9V alkaline batteries I now think it is a worthwhile investment even at the full price; at least for me there have been many times I replaced a battery "just in case", not trusting it to make it through a gig.

You could accomplish most of that with a DMM and a few accessories to measure the battery voltage and the current draw. But one thing strange during the test is that the LED on the footpedal will blink briefly- even if the footswitch is set to the bypass position. How does it do that???

I suspect that there is a custom chip inside designed by Keith McMillan which runs the tests- custom chips are not cheap but I guess that he invested the profits from some of his other devices to put these on the market (rather than just taking the money and running as seems to be the case with most companies). I am sure that he will eventually show a profit on this as more people discovers its usefulness.

The Batt-O-Meter has a slide switch on the left side to select between alkaline, rechargeable and carbon zinc batteries, along with the "hold to test" button. On the right side you have a 6" cable with a special TRS plug along with two terminals for testing a loose 9V battery. (You can measure a 1.5v battery by holding the + end to the + 9v terminal and the tip of the TRS plug to the - end of the battery.) The circuitry automatically differentiates between 9v and 1.5v, which can lead to false readings with the circuit thinking that a very weak 9v battery is a 1.5v battery.

When you plug the TRS plug into the stomp box or active bass the display might cycle through "AL" (for alkaline) followed by "VOL" followed by the actual voltage measured and then "HRS" followed by the estimated hours left in the device. If you hold the button down with nothing connected it will run a self test: "SLF" "yES" "PRC" and "99" for a fully charged 9 volt battery. Quite a chip!

Steve Ahola