1
\$\begingroup\$

I am trying to find a replacement part that goes on a PCB of an LED C size battery-driven hanging lantern light. One of the two leads of the small barrel shaped component corroded and broke off near the surface. Can anyone be of any help in providing what I can use to replace the barrel? There is no stamping of any kind, it just a metallic small barrel with two leads soldered to the PCB.

small barrel component

side of PCB where barrel comp is attached

opposite side of PCB where C size batteries will be located

\$\endgroup\$
1
  • 3
    \$\begingroup\$ looks like a tilt switch \$\endgroup\$
    – jsotola
    Commented Oct 4, 2023 at 18:37

1 Answer 1

3
\$\begingroup\$

That's most likely a crystal, there's probably a micro-controller under one of those black epoxy spots and the crystal is used as it's timebase.

Crystals in that package style are commonly 32.768 kHz, which is a power of 2, so easily divided down to 1 Second for real time clocks (they're often listed under the name "clock crystal"), but they can be other frequencies.

Others are saying it could be a tilt switch as there are some of those in a similar package. If it is one something should happen when the lantern is turned sideways or upside down such as the light going out (not sure why they would do that, it's not like a kerosene lantern that could catch fire if you knock it over). If it did have some functionality related to tipping it over that would indicate a tilt switch. The power switch has a 4 hour and 8 hour setting, which would mean it has to keep track of time somehow and a clock circuit using a crystal seems reasonable. Even without the need for accurate timing microprocessors need a timebase, and a crystal is one way to get one.

\$\endgroup\$
10
  • \$\begingroup\$ It does look like a crystal, but why would a lantern need an accurate time base? Could be a mercury tilt switch. \$\endgroup\$
    – Mattman944
    Commented Oct 4, 2023 at 19:38
  • 1
    \$\begingroup\$ @Mattman944 Look at the switch, it says "4H - OFF - 8H". \$\endgroup\$
    – GodJihyo
    Commented Oct 4, 2023 at 20:08
  • \$\begingroup\$ Thank you all for your answers, I really appreciate this. So since I am not as smart as you folks, I presume that I would look for a clock crystal. I googled clock crystal and found them at Digikey kHz 32.768: part no 535-9034-ND and Dove Elec Comp. And it is is a 4H - OFF - 8HR. Am I on the right page? \$\endgroup\$ Commented Oct 5, 2023 at 19:10
  • \$\begingroup\$ @StephenZewe I can't say 100%. If the lantern when working didn't do anything different when tipped over or turned upside down then it's more likely to be a crystal than a tilt switch. If it is a crystal 32.768 kHz is likely to be the correct one, but without a schematic or any markings on it there's no easy way to be sure other than getting one and trying it. If you have another working one and the right test equipment such as an oscilloscope you could just measure it and see. \$\endgroup\$
    – GodJihyo
    Commented Oct 6, 2023 at 4:05
  • \$\begingroup\$ I can assure you that the lantern did not do anything when tipped over. I am just a home owner that has no background in this sort of thing, it was suggested that I reach out to the experts to ID the part and thereby find a replacement. Since these crystals are rather inexpensive, I think I'm going to find one and solder it to the PCB and see what happens. I thank you very much for your input and time. \$\endgroup\$ Commented Oct 6, 2023 at 14:16

Not the answer you're looking for? Browse other questions tagged or ask your own question.