Circuit Design Help

Thread Starter

Docgarza

Joined Apr 10, 2024
2
I’m a new member and new to the journey of learning on this subject. I would love to take the time to learn everything so I could design it myself. I actually have been trying for the last 4 months, but its hard to balance with work and personal obligations. This idea isn’t for personal gain, so I feel like it can’t wait for slow learning. So if you can contribute a circuit design or would like to work more personally to make it better, please drop a line. If you want to be negative, I’m sensitive. I’ll cry.

I have been riding the bus now for a while in a major city, and not many of the bus stops are lit up. Waiting in the dark in 10deg weather is rough. A bus blowing by you because they didn’t see you is heart breaking. I would like to put blinking LED strips on all signs that can be recharged by 2”x2” solar panels. They are activated by a push button and stay blinking for 30min. Powered by (4) 3.7V 1.85-2.2Wh rechargeable batteries. I would appreciate a basic schematic for mass production, as I’m recycling all of the materials. I’m collecting various electronics at the goodwill and similar places to recycle lights, chips, transistors, etc. What are items I could look out for that will have the components needed to bills this particular design?

Thanks for your time folks.
 
For 30min timer you need a counter IC. The blinking you can do with two signal transistors (multivibrator). This multivibrator can feed the counter. For controlling power Leds a power mosfet (low voltage type like 30V) is necessary.
 

WBahn

Joined Mar 31, 2012
30,252
You are going down a self-contradictory rabbit hole.

You say you want a design for mass production (which is not completely unreasonable since a decent-sized bus system is probably going to have thousands of bus stops), but then you say that you plan to scavenge all of the parts from essentially random odds and ends from various surplus stores. That is about as the opposite as you can get from mass production.

Mass production entails designing something so that you can make thousands of identical items, using identical parts that are packaged to facilitate fast and efficient automated assembly. Just consider one of your items -- your 2" x 2" solar panel. What are the chances that you can get thousands of identical solar panels by pulling them from stuff you find at various Goodwill stores? Answer -- zero. If you managed to find, say, a thousand solar panels after going to every store, you would probably be lucky to have more than a few dozen that were the same make/model and then the chances that those were actually suitable for your application is probably very low.

But let's ignore all of that. If someone where to do all of your work for you and hand you a design and bill-of-materials for this thing suitable for mass production, who's going to build all of them? Who's going to pay for all of them? Who's going to install all of them? Who's going to maintain all of them? Who's going to replace all of the ones that will get stolen?

The best solution for YOU is, like was already suggested, get a runner's or bicyclist's headlamp and put it on when you are at a bus stop. That will make it highly likely that the driver will see you.

If you really want to try for a solution for every stop, pitch it to the bus operator and/or the city and lobby them to adopt the idea and become responsible for the implementation of it.
 

Thread Starter

Docgarza

Joined Apr 10, 2024
2
You are going down a self-contradictory rabbit hole.

You say you want a design for mass production (which is not completely unreasonable since a decent-sized bus system is probably going to have thousands of bus stops), but then you say that you plan to scavenge all of the parts from essentially random odds and ends from various surplus stores. That is about as the opposite as you can get from mass production.

Mass production entails designing something so that you can make thousands of identical items, using identical parts that are packaged to facilitate fast and efficient automated assembly. Just consider one of your items -- your 2" x 2" solar panel. What are the chances that you can get thousands of identical solar panels by pulling them from stuff you find at various Goodwill stores? Answer -- zero. If you managed to find, say, a thousand solar panels after going to every store, you would probably be lucky to have more than a few dozen that were the same make/model and then the chances that those were actually suitable for your application is probably very low.

But let's ignore all of that. If someone where to do all of your work for you and hand you a design and bill-of-materials for this thing suitable for mass production, who's going to build all of them? Who's going to pay for all of them? Who's going to install all of them? Who's going to maintain all of them? Who's going to replace all of the ones that will get stolen?

The best solution for YOU is, like was already suggested, get a runner's or bicyclist's headlamp and put it on when you are at a bus stop. That will make it highly likely that the driver will see you.

If you really want to try for a solution for every stop, pitch it to the bus operator and/or the city and lobby them to adopt the idea and become responsible for the implementation of it.
I guess I should have worded this better. The term “mass production” for me just means I have to make a lot. Since I have to make them by hand, I’m looking for the most simple setup that would be the cheapest for me to make. Like you said, each city has thousands of bus stops. I’m going to have to make a lot. And I won’t be scavenging all of the parts, but as many as I could. There’s so many disposable products that can be reused if broken down to their components. Disposable vapes alone are filling land fills with battery acid. Why not reuse some of the things to make other people’s lives easier and safer? It would take years for me to do one city alone. I’m hoping with a little bit of community, it won’t take as long.
Maybe I get 250 of them done over the next year. Thats 250 stops that make a difference. Thats 250 opportunities for someone to see this and want to contribute their time and good energy to help other people. With enough people talking about it, supporting it, maybe it will gain enough traction for lawmakers to implement.

I asked nicely for people to leave their negativity out, but I guess that request was lost on you
 

MrChips

Joined Oct 2, 2009
30,987
The response was not negative but practical and realistic. To me, making more than 10 units is "mass production".
You would need approval by authorities even to attach a single unit to a bus stop. My suggestion of a runner's light still stands.
 

MisterBill2

Joined Jan 23, 2018
19,054
The very best part of the advice was about presenting the problem to either the bus company or some portion of the city government. To gain acceptance for any plan, it has to deliver a real benefit OR solve a believable problem, such as loss of bus rider fares. So that is a possible path to a solution.
To solve your own personal problem, assuring that you were very visible at the bus stop is the solution. That can be simpler and cheaper. A string of LED lights on a hat , that flash brightly , and possibly another string to temporarily light the bus stop sign to show that a rider was waiting. Battery powered flashing LEDs could be a solution. Probably nothing will get a driver running behind schedule to stop, though.
 
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