Developing / editing existing power bank circuits for our new product

Thread Starter

kkmcdesign

Joined Jul 21, 2017
8
Hi Guys,

We are developing a really cool little product that contains a small power bank for phones. I'm a product designer and have the design all sorted and a manufacturer to produce a Rigid flex PCB to fit the product.

Only issue is that i have no electronics experience at all!

All the circuits i can find are close but slightly wrong for our needs.. I and asking for help really, as i have no idea how to edit these circuts and make an electronic schematic design to send for sampling

We ideally want the circuit all SMT as it needs to be small, and from what i can see, it would be good to base it around the ACT28xx IC family.

Other requirements
Micro USB in 1A 5w
Micro USB out 1A 5W
Protective fall backs for as much as possible
3 x led power indicators
No "ON/OFF" button, USB connection powers up product

I have attached our PCB design so you can see just how small space we have to work with.

Does anyone have the time either show me how to make this design, or to find me a design that will do all of this? Electronics really does go a bit over my head!

Would be great to hear back on this
cheers

Kit
 

Attachments

Alec_t

Joined Sep 17, 2013
11,650
Welcome to AAC!
Why use micro USB for both input and output? That's asking for trouble, as some eejit is going to reverse the connections. Adding protection circuitry to prevent that will complicate things.
 

Thread Starter

kkmcdesign

Joined Jul 21, 2017
8
Haa there is always someone isn't there! We actually have to use both as Micro USB due to size constrains. If we need to add circuity to stop issues, then that is what we will have to do as we physically cant fit a USB in.
 

AnalogKid

Joined Aug 1, 2013
8,596
So, even though you "have no electronics experience at all!", you are the product designer of an "electronics" product. And you have it "all sorted out" except for the ... wait for it ... electronics. Is that an accurate summary?

You are asking for a lot, especially as you have given basically zero information to work with. What does the product do? What do the electronics do? ACT28xx is useless as a part number, so how about a data sheet? Is this a consumer product, or industrial/medical/military/space/nuclear environment? Rigid-flex is not a beginner's technology; how are you designing for this?

And, assuming you give us enough information to do the design for you, how will you determine if the design will work?

Where are you located?

ak
 

AnalogKid

Joined Aug 1, 2013
8,596
we physically cant fit a USB in.
What about a mini on one end and a micro on the other?

Thinking about it, if I've decoded the secret clues correctly, there is a way to keep identical connectors on both ends of the product and make it automatically reversible, so it doesn't matter which way the power is going through the design.

ak
 

Thread Starter

kkmcdesign

Joined Jul 21, 2017
8
That is a perfect summery! i am a trained product designer, not an electrical engineer..

I have found this circuitry : http://www.richtek.com/Products/Battery Management/Single Cell Li-Ion Battery Charger/RT9480
But i think they use there own IC Chips and it has features we would need to remove such as the button and additional LED's. I have asked them for help with it but they are very slow to respond and i cant see them helping much.

and

I have found this :http://www.active-semi.com/products/dcdc-converters/high-power/act28xx/01/
Which sounds similar but i don't know how to do a lot with it.

The product is a consumer power bank for charging smart phones, Simple as that. Power in and a power out! its just incorporated into another product that id like to keep quiet for now if you don't mind.

In terms of the design for the rigid flex, we have a company that can do the design, they just need us to provide the electronic schematic design.. hence why i asking for help with that.

If both Micro USB ports can do either, it would be perfect!

We want it to be safe and to have prevention for power surges and over charging etc, which i think these IC's actually have built in?

This any help?
 

OBW0549

Joined Mar 2, 2015
3,551
Does anyone have the time either show me how to make this design, or to find me a design that will do all of this? Electronics really does go a bit over my head!
That all depends on how much you're willing to pay.

All you've done so far is the easiest 1% of the total design task-- a circuit board dimensioned drawing. And now you want someone else to take on the remaining 99% of the design work, the part you don't have a clue how to do.

So what's it worth to you? And, what percentage of the profits from this commercial product are you willing to assign to whoever performs that design work?

Surely you don't expect free engineering work-- do you?
 

Sensacell

Joined Jun 19, 2012
2,598
they just need us to provide the electronic schematic design.. hence why i asking for help with that.
As a product designer, you will understand how important the concept of "workflow" is.
Consider that the workflow for this project is totally unknown to you, it's going to be very hard to succeed.

Hire an engineer to do this, don't muck around.
 

Thread Starter

kkmcdesign

Joined Jul 21, 2017
8
Ok, guys i do not expect anything for free and there is no need to tell me how much work i have to do. I have been developing this for at least a year and i know there is a lot to do.

I would not however go as far as saying i have only completed 1% of the work... an electrical engineer who has a circuit design but no product to go with it, is not 99% of the way to a final retail product!

There are companies that i can contact to do this last stage of the design for me, but i prefer to give my money to a self employed designers or enthusiasts. If this is not possible, should we just shut down the thread now?

I came here asking for help, and to see what people could offer. I have honestly provided about as much as i know and i didn't think that a power bank circuit was a particularly big challenge for a website full of people who are dedicated to electronics.
 

OBW0549

Joined Mar 2, 2015
3,551
...an electrical engineer who has a circuit design but no product to go with it, is not 99% of the way to a final retail product!
Any EE who creates a circuit design without first having a VERY well-defined product concept is an idiot, not an engineer. In my 40+ years in this business, I've never met anyone who worked that way-- at least no one who stayed employed very long.

Is that how you think electrical engineers work? Seriously?
 

Thread Starter

kkmcdesign

Joined Jul 21, 2017
8
Why do you think i don't have a VERY well defined product concept? as i said, all the design work is finalised, but the circuit design.. that bit is not my job.
I don't know how this has come to such an offensive judgement on my project from someone who has read 3 posts from me asking for help!
Do you get much freelance work? ;)
 

Sensacell

Joined Jun 19, 2012
2,598
I think the negative reaction comes from having lot's of experience with situations just like this.

Suggesting chips, even though you say you have no experience with electronics give insight into how you perceive the situation.

You have trivialized the project in a way that indicates that you would be a difficult client.
Half the job would be illuminating how far from from done you really are, an exercise that you might resent paying for.
 

Thread Starter

kkmcdesign

Joined Jul 21, 2017
8
I perceive the situation as this, I need a person to design a power bank circuit to fit in a power bank.. hence why i asked.
You may think i'm trivialising it, but its a "trivial" part of the project. i'm sure in the time i have wasted on this forum, one of you could have provided a circuit and i could be all done.
Oh well.. Live and learn ey! Forums are not worth the effort :)
 

Papabravo

Joined Feb 24, 2006
14,420
I perceive the situation as this, I need a person to design a power bank circuit to fit in a power bank.. hence why i asked.
...
.. Live and learn ey! Forums are not worth the effort :)
Providing a place to find designers for product developers is not one of the purposes of this forum. If you search the 100,000 plus threads you will not find many successful connections. Product developers never have an adequate set of requirements and the never want to pay what the work is worth. What is not worth our time is responding to requests like this because they are invariably destined to go absolutely nowhere. If you find the person you are looking for and the result is a commercial success come back with that story -- I'll might even send you a small reward for such a tale.
 
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