Whats this component?

Thread Starter

davidfet

Joined May 13, 2020
31
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.



20200622_154906.jpg
 

Thread Starter

davidfet

Joined May 13, 2020
31
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?
 

jpanhalt

Joined Jan 18, 2008
11,088
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

davidfet

Joined May 13, 2020
31
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:

LED
+ 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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