Author Topic: Wanted: portable power supply/regulator designer  (Read 2824 times)

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Offline catskullTopic starter

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Wanted: portable power supply/regulator designer
« on: May 17, 2018, 04:21:15 am »
I am seeking someone who can design a power regulator for a portable electronic device. I have a few operating constraints:

Input: 4xAA batteries (~6vDC)
Outputs: 5vDC, -19vDC

Since it's a portable device, efficiency is a top priority. The design should take into consideration part availability and cost. Ideally the BOM should be under $5 USD if possible. Bare minimum deliverable would be a schematic and BOM, but if you have PCB design experience that would be a great bonus (would pay extra for that). I don't care what you use to design the PCB!

If this sounds like something you can do, message me here or email me at bro {at} catskull {dot} net and include a ballpark price and I'll get you any more details you need!
 

Offline Brumby

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Re: Wanted: portable power supply/regulator designer
« Reply #1 on: May 17, 2018, 05:51:14 am »
If you want someone to get interested (which won't be me) - you're going to have to include a few more parameters.  You might like to start with current requirements at the voltages given.
 

Offline rx8pilot

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Re: Wanted: portable power supply/regulator designer
« Reply #2 on: May 17, 2018, 08:15:13 pm »
......yes.....details.

Especially expected lot sizes. If you specify a BOM cost target, it is only valid if the volume is appropriate. For $5 BOM cost, you can expect a very large volume. Also, with very low cost - your specifications should be rather modest.
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Online Ian.M

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Re: Wanted: portable power supply/regulator designer
« Reply #3 on: May 17, 2018, 08:41:02 pm »
Also assuming the main output ois the 4V one, 4x AA cells in series results in a considerably more complex design than either more or fewer cells would.   When the cells are brand new they'll deliver about 6.2V dropping to 3.6V fully discharged.   That means the regulator must be capable of buck-boost operation.   

3x AA would have a maximum voltage of about 4.65V dropping to 2.4V fully discharged so a simpler boost only regulator would be sufficient.   There's probably something already available intended for use with a single cell LiPO that will tolerate that input range and that you can buy a demo board for.

6xAA would start at 9.3V dropping to 4.8V at full discharge, but there isn't a lot of energy left in an AA cell between 0.9V and 0.8V on the discharge curve, so if you use a simple buck regulator, you'll still get 90% or more of the energy out of the battery pack before the 5V rail drops out.

Its pointless to try to go further without hard specs for maximum, minimum and average load current for each rail, and whether or not the rails must be maintained for long periods in standby or sleep modes.
 
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