Author Topic: Weird circuit in children toy  (Read 395 times)

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Offline frenky

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Weird circuit in children toy
« on: December 10, 2018, 06:37:54 am »
I have bought a bathtub toy which has a water pump in it and it stopped working on the first day.
I thought pump has died so I took it apart to see which model should I order online.
After a month I got it and replaced the faulty one.
But this new pump also was not working so problem was elsewhere.
I took it completly apart and found capacitor in series.
I have never seen that in DC circuit. Any idea why the cap is there?

The whole circuit is battery, capacitor, switch and 5v dc pump in series.
« Last Edit: December 10, 2018, 06:41:00 am by frenky »
 

Offline frenky

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Re: Weird circuit in children toy
« Reply #1 on: December 10, 2018, 06:44:36 am »
The toy is powered by 3xAA batteries and pump looks like this:


And toy:

« Last Edit: December 10, 2018, 06:50:05 am by frenky »
 

Offline David Hess

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Re: Weird circuit in children toy
« Reply #2 on: December 10, 2018, 07:01:32 am »
The part is not a capacitor.  It might be a PTC thermister used as a resetable fuse to prevent damage to the battery in the event that the motor seizes.

 
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Offline frenky

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Re: Weird circuit in children toy
« Reply #3 on: December 10, 2018, 08:10:33 am »
That makes sense. Perhaps its to low value and its limiting current too much. Because pump was working but it did not produce enough water pressure to spin the accessories.
 


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