I have multiple stationary baby items for my son Oliver that require a serious supply of batteries each month. I would like to hook a few of these stationary items up to wall warts to conserve the constant expense of alkaline purchase/recharging of batteries. I currently have two spare wall warts laying around the house: first at 9V/1A and the second at 12V/1A. I am located 15km from a Mouser warehouse in case the garage will not suffice.
Two items I would like to wire up right now include a baby rocker which requires one D battery and a crib which includes a mobile electronic toy rotation device requiring 3 AA batteries.
I was lucky enough to get these from a baby shower and due to my current job situation, I can't upgrade. I would like to build a circuit for both but will discuss the baby rocker at this point.
This circuit would need to accept either voltage from the wall warts and drop it to 1.5V to run the baby rocker's vibrator. I have been looking at the 780x type linear regulators at this point but am not sure if this is the way to go. I wanted to see what you might recommend. I need advice that will not only eliminate batteries, hopefully save electricity, and also be easy to solder as I do not have the skills and equipment for SMD applications.
Thx in advance for your help!
Best Answer
I'm surprised the rocker doesn't have a DC inlet already.
You could connect the 9 V supply to a linear 1.5 V regulator, and it would be easy, but you'd be wasting a lot of energy. It would be better to just go to a thrift store and try to find wall warts that are close (more appropriate transformer turns ratio) to the voltage you need. Regulating a 3.3 V or 5 V supply down to 1.5 V would be more efficient. The voltage might not even need regulating, or could be anywhere within a large range and still work, but you'd have to take the products apart and see what they feed into. I ruined a digital camera by accidentally using a higher voltage adapter, but many things don't care.