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Circuitbenders Forum => Circuitbending discussion => Toys => Topic started by: mr_wowow on April 22, 2015, 08:16:26 AM

Title: Power 3V toy from 9V power supply LM317
Post by: mr_wowow on April 22, 2015, 08:16:26 AM

Hi everyone circuit benders,

How can I power a 3v toy (chinese buddha machine) from a 9v delay pedal?
I know LM317 can help me but I would like to know which components values I have to use.
I have TO-92 LM317 version
Can some help me to understand how to use and make connections?

Thank you in advance

Mr_wowow

Title: Re: Power 3V toy from 9V power supply LM317
Post by: Circuitbenders on April 22, 2015, 07:22:56 PM

Look at the datasheet. Page 5 https://www.fairchildsemi.com/datasheets/LM/LM317.pdf (https://www.fairchildsemi.com/datasheets/LM/LM317.pdf)

or just spend 99p on a step down converter from ebay like this http://www.ebay.co.uk/itm/201157226757 (http://www.ebay.co.uk/itm/201157226757)

Title: Re: Power 3V toy from 9V power supply LM317
Post by: wax+wire on April 30, 2015, 08:09:17 AM

so one of these would do a nice voltage starve / power sag on a DC powered (not battery) powered device?

Title: Re: Power 3V toy from 9V power supply LM317
Post by: Circuitbenders on April 30, 2015, 04:46:16 PM

good question.

Theres a limit to how low it can go. For that little module it looks like 0.8v, but i don't see why it wouldn't work as a voltage drop controller on something like a Casio SA. Thats assuming that 0.8v is low enough to make it crash.

Something is making me vaguely uncomfortable about the idea, but i'm not entirely sure what that might be as i can't actually think of any potential issues.

Give it a go!  ;)