Children's toys and dying batteries

[Will__]

Some of my little son's toys require batteries for the sounds they make. (Usually electronically prouduced familiar nursery rhymes.

One of them, i've noticed, when the batteries are no longer strong enough, starts slowing down and making the music sound terrible - off pitch, and slower, much like a dying walkman of old.

This confuses me though - I am more than pretty sure that none of these cheap mass produced toys have any kind of mechanical music reproduction system - it's all chip based, so why on earth does it slow down instead of just not working?

It's analagous to a portable CD player dying - an old mechanical toy might die like this, like a walkman, but a CD player, when it runs out of juice, just stops. Why don't our toys follow this more predictable behaviour?

Thanks.

[markysngc]

I would guess it would be that the circuits in them would have a timing chip somwhere intigrated into it to keep the tempo correct and if the voltage on that part of the circuit is low due to the battery running out the timing chip would be sending it's timing signal out slower but the rest of the circuit would still be staying in sync with the slower signal.

A protable CD player is going to be bult a bit more expensivly and will stop of it's own accord when the battery gets low rather than trying to play on when there is not enough power

[heathfield]

It's just possible that the sounds are mechanical rather than from a chip. Remember the first dolls with speech? You pulled a cord which wound up the mechanism and then retracted back into the doll. There must have been millions of these made, and perhaps later some had a motor fitted that replaced the cord. Just a thought.