TV-B-Gone_JeonLab power source

As same as Adafruit’s original TV-B-Gone kit, my modified TV-B-Gone_JeonLab accepts any DC power source within 3-5V. The micro-controller, ATtiny85V, runs within 1.8-5.5V, but the IR LEDs consumes more power than the micro-controller, you need to keep the source voltage at least 3V.

Adafruit includes 2 AA battery holder in their kit, but I will not include any battery holder or connector in my kit in order to give more flexibility of choice of power source.  As long as the voltage of the source is within 3-5.5V, any battery or supercap can be used.  For example, 2-3 AA or AAA alkaline batteries, 3-4 rechargeable batteries like NiCd or NiMH, Li-ion (or Li-PO) rechargeable batteries or 2 of 2.5V (0r 2.7V) supercap (at least 10F).

As I mentioned a few times before, I like supercaps. Even though they can not hold much charge compared to batteries, they can be charged quickly (less than a minute) through USB or 5V wall adapter and small and light.  So I decided to attach two supercaps to my TV-B-Gone_JeonLab, but I wanted to compare the sizes of 4 and 2 AA battery holder and AAA batteries.

TV-B-Gone_JeonLab size_4AA

TV-B-Gone_JeonLab size_2AA

TV-B-Gone_JeonLab size 3AAA & 1A

The actual size of my modified PCB is slightly smaller than Adafruit’s which fits nicely at the back of 2 AA battery holder. Anyway, I figured someone would be interested in having supercaps as a power source and here is how I did.

First thing I did was to attach a male header a guide (plastic piece on one side) for assuring correct polarity of connection.

connector male header

But this one was too tall compared to the other components.
connector male header before cut

So I cut the plastic guide and pins a little bit.
connector male header after cut

Using a small piece of double sided tap with foam two supercaps (2.5V, 10F) were attached to the bottom of the PCB and soldered in series together.
TV-B-Gone_JeonLab supercap soldered

TV-B-Gone_JeonLab sideview with supercap

In order for ensuring the supercaps in place securely, a thin cable tie was used.
TV-B-Gone_JeonLab top view cable tied

TV-B-Gone_JeonLab cable tied bottom

Now it’s time to make the USB cable connector. I cut one of those USB cable found from my junk box.
USB cable wires

And attached female connector to the red (+) and black (-) wires of the USB cable.
USB cable power wires red and black

female connector before finishing

When you insert those spring pins in the connector housing, make sure the stopper to be inserted all the way in until it makes click sound (blue arrows in the picture below).
female connector assembled_click

Finished with a heat shrink tube.
female connector shrink tubed

Charging from my laptop computer.
TV-B-Gone_JeonLab with supercap USB charging

Look how small it is in my hand.
TV-B-Gone_JeonLab size in hand

And it works!!
TV-B-Gone_JeonLab_supercap in hand

With one full charge (about one minute), I could turn one of my TVs on and off more than 40 times from about 6.5m (21 feet) away. Of course I used STOP button right after it turned on (or off) the TV. It does save power!

If you want to buy the kit (without supercap or battery holder), PCB, or firmware loaded ATtiny85V or any combination, email me for a quote.


4 thoughts on “TV-B-Gone_JeonLab power source

  1. I like your idea to use supercaps.

    Three questions:
    1. Is it possible to connect the supercaps (to charge them) on a simple battery-holder (without e.g. resistors)?
    2. Are you don’t afraid of short circuits, if you plug the usb-cable in your laptop?
    3. How long keep the supercaps their power (without usage)?

    Thanks you for sharing.

    • 1. As long as the voltage of the batteries is about 5V, you can connect directly.
      2. I haven’t experienced any short circuit but you need to be careful. One way to check is to measure the voltage of supercaps before connecting it to the computer. If it is shorted , the voltage reading will be 0V.
      3. If you don’t use it, the supercaps’ discharge will be very slow.

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