Whats this component?

Thread Starter


Joined May 13, 2020
This is from a 'dancing candle'. The LED illuminates a piece of plastic (wick) which has a small magnet on its base, that gets flicked by the electromagnet.
The component 'YB', seems to create a pulse, wondering what it is...

Also, when the battery starts going low, the magnet/pulse seems to pull current away from the LED causing it to flicker a little. I tried sticking various values of capacitors (electrolytic and ceramic) to decouple the LED, but does not seem to help. Tried this on the YB component too.


Thread Starter


Joined May 13, 2020
My bad...

1) What is the component 'YB'? (possibly HT828- unable to find info on that number0
2) Is there a way to prevent the LED from flickering as the battery draws down?


Joined Jan 18, 2008
YB is a code. It can match several components, but judging from its case and number of pins, it is probably a transistor. One good match is the
5LN01SS : https://www.onsemi.com/pub/Collateral/5LN01SS-D.PDF

That's an N-channel mosfet.

As for your second question, it would require quite a large capacitor to do what you suggest, but if that worked at all, it would only be for a short time. Nothing lasts forever. Just put in a new battery then that happens. There's a circuit called a "Joule thief" that might help.

Thread Starter


Joined May 13, 2020
Thanks jpanhalt. So they are using the mosfet as a switch, that when it switches on, it gives a 'kick' to the electromagnet?

Pretty sure the layout is:

+ to 68r then vcc +
- to ground

Electromagnet (EM)
+ to 360r to vcc +
- to mosfet

mosfet (edit- looks more like a transistor to me, change gate to base etc.)

G: to vcc+
D: to - gnd
S: to the EM - pin

Any ways to make this more power efficient?
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