DC Voltmeter that speaks in Morse

I have a couple of battery powered radios that do not have an in built voltmeter or low battery cut off. After considering various options I settle on the DC Beeper Kit from Jackson Harbor Press

DC Beeper with battery

At the press of a button this kit announces the voltage in morse and provides both a Timer and Low Voltage disconnect function.

Whilst it functioned as expected and fine for a simple inline volt meter, I felt there was room for improvement. Following an email exchange with designer Chuck WB9KZY I received a new chip with a minor modification. Now if Pin 6 of the micro is grounded when the unit is powered up it will announce the voltage straight away, and then continue to function as per the original design.

In this configuration the DC Beeper can be used like a simple voltmeter without the need of a third hand to press the button, or as my case on connection to the battery pack I have an instant announcement of its voltage.

Close up of Top, Heat shrink on the FET Tab to protect against shorts
Underside with the Piezo Buzzer held in place with clear heat shrink

To facilitate alignment I changed the supplied trimmer for one that would allow for “side” adjustment

6 thoughts on “DC Voltmeter that speaks in Morse

  1. Looks like a very useful accessory. The plug in 7 segment modules that cycle thru each cell are also good, but you have to read them! This is a no hands, no eyes battery condition monitor. And pretty cheap too.

    • Hi Paul,
      For a couple of reasons I have moved from the typical sota battery pack (Li-ion 3s style) to the individual cells in the photo or a USB battery bank with dc-dc boost regulator hence the need for something a bit different. At some point I need to post my thoughts on why I have changed battery system.
      73, Warren.

      • I am interested in the USB mobile phone power bank and DC DC boost converter option. After the activation you can charge your mobile phone!

        I have two phone power banks and have wondered about their utility as a power source for a QRP CW rig. Even two in series for 10v would work with my rigs but the DC DC converter is the right way of doing it.

      • Hi Paul,
        I did think about connection 2 USB battery banks in series, and if I remember correctly gave it a go. But in the end felt it was a bit “ugly” and fraught with the risk of smoke escaping somewhere. Seems I had best get a post together on the subject of batteries.
        73, Warren.

  2. Pingback: Portable power options | vk3byd

  3. Pingback: Soda Pop QRP transceiver | vk3byd

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