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Bernd
Fireman



Posted - 07/14/2018 :  12:10:28 PM  Show Profile  Visit Bernd's Homepage  Reply with Quote
quote:
Originally posted by Frank Palmer

Bernd and Dan, this is going to be fantastic.



Hi Frank,

I've been involved with this idea from about 2012 on the Freerails forum. That is where I met Dan. I was interested in just radio control and a minimum of wiring for the layout. When Dan came along and introduced battery power and the possibility of wireless charging, I was very hooked. Unfortunately there was a regime change on that sight and in my opinion it's gone down hill. So I presented some ideas of DYI battery power on MRH and didn't get much of a response. The members are interested, but want it to be plug and play and where can I buy it. Also there's always a few that aren't up to date on Li-Po batteries and it scares the b-jesses out of them. Then when the sub-forum was started here I was glad to see some interest. That seemed to wan for a while. Now that Dan has shown up I hope we can carry on a decent conversation on the subject and more will join. Time will tell.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Edited by - Bernd on 07/14/2018 12:13:06 PM

Country: USA | Posts: 2677 Go to Top of Page

Bernd
Fireman



Posted - 07/14/2018 :  12:23:20 PM  Show Profile  Visit Bernd's Homepage  Reply with Quote
quote:
Originally posted by Norton

Bernd,

As part of your experimentation process I might suggest trying different ratios on the Xmit and Rcv coils to see what results you get from the test. If memory serve me correctly, the turns ratio should produce either a higher or lower voltage based on which way the ratio goes. That's the basis for how a transformer works. It either is a step-up or a step-down transformer based on the turns ratio between the coils. That may assume the same size for the coils but I have never experimented with this so I could be wrong. This test would require you to make your own coils but I get the impression you would be doing that anyway.



Hi Norton and welcome to the thread. Glad you joined in.

I plan on doing just what you suggested. I've built a resistance soldering unit using a microwave transformer. I wound the secondary with just two coils of welding cable to get from 120 volts to around four volts and over 400 amps at the terminals. So yes I'm familiar with turns ratio.

Your impression is correct. I am going to try, note I said "try", to make my own. I came a cross a website that explains what to use to make your own induction coil for charging. I used to get this magazine way back when I as very interested in electronics.

http://www.nutsvolts.com/magazine/article/august2013_Bates

Bernd



A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

Norton
Engine Wiper

Posted - 07/14/2018 :  2:08:22 PM  Show Profile  Reply with Quote
That resistance soldering transformer sounds like a real bear. I tried my hand at winding some turns many years ago, when I too was deeply into electronic hardware.

I figured, based on carefully reading your postings on this subject, that you are quite familiar with what you're doing. My post was more a matter of me butting in on a subject that I know little about but have a background in the technology of.

I will read this frequently to see how this all goes for you, even though I will never use it. I like the intellectual stimulation.


The V & T lives in my garage. Soon...

Norton

Country: USA | Posts: 181 Go to Top of Page

Bernd
Fireman



Posted - 07/14/2018 :  5:16:43 PM  Show Profile  Visit Bernd's Homepage  Reply with Quote
That resistance unit is great for fast soldering. Greatly improved some of my solder joints.

I know enough to be dangerous. I'm not afraid of experimenting. Occasionally there is a puff of smoke and some colorful words spoken.

Glad you butted in. Feel free to do that now and then.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

DanT
New Hire

Posted - 07/14/2018 :  9:47:13 PM  Show Profile  Reply with Quote
Bernd,

Thanks for the Central London Area Group link. I read through it briefly, but have to review it again in more detail. It seems not to follow the Qi Standards/Protocols and is mainly focused on coil coupling, all well and good as a subject by itself. I have to admit being oriented years ago to the Qi standard. It was the only one around, so studied it as much as I could. This video gives you an inkling of its complexity.

https://www.youtube.com/watch?v=c3dGP4ulBAk

Re coil similarity, I'm assuming coil sizes should be the same to obtain resonant frequency. Whether pairs of coils of different size or shape can somehow establish resonant frequency is unknown to me, but my impression is coils should be the same to obtain the best power transfer. I will be testing mostly pairs of similar coils for this reason. Coil size is only one variable among many. I also need to move on to infra-red switching, First Person View and upgrading engine sound projects. Then, IMO, I'll have a cab control system traditional DCC can't compete with.

Dan



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Bernd
Fireman



Posted - 07/15/2018 :  09:19:07 AM  Show Profile  Visit Bernd's Homepage  Reply with Quote
You're welcome. I found that group through the British web site: http://www.rmweb.co.uk/community/ They have some interesting material. That's where I found out about the eddy current drive system. I think I know why you need to follow the Qi protocols, but I won't say. It'll just have modelers asking questions.

The video was very interesting. As I said a lot of info is based more on everyday consumer products, such as fast charging for phones and medical equipment. I feel that in applying this tech toward model railroading that we don't need that speed. That's one of the reasons Li-Po's got a bad reputation. The fly boys were hot charging them off their car batteries causing them to catch fire. Yet when Li-Po's are charged at their normal rates they are fine. So the question in my mind do we need such a complicated system to charge batteries or is that needed for a possible product for consumer consumption?

I plan on getting a few more of those boards and see if I can wind my own coils. For the what they cost I can afford to let the magic smoke out.

Looking forward to your results from testing. Sounds quite complicated from the last sentence. I hope you succeed.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

DanT
New Hire

Posted - 07/15/2018 :  11:50:30 PM  Show Profile  Reply with Quote
Ah! RMweb! I posted on this forum about 4 years ago, only to be dissed by a fellow American. Go to Modeling Zone/Special Interests/Radio Control/Post #428 on Page 18. I had advised them of my success in getting sound with BPRC. Some interesting comments followed. You can't please everyone...too bad he didn't understand my models are for Proof of Concept, not ready-to-run offerings for purchase.

Fast charging LiPo's and the features the Qi Standard offers are really two separate issues. I think we both agree slow charging is the way to go. But how we charge can address issues of safety, efficiency and compatibility between devices from multiple manufacturers. The Standard provides a controlled charging process including shutdown when charging is complete. Nice to have IMO. I think consumers/modelers would want it as well.

Good luck with your project.

Dan






Edited by - DanT on 07/15/2018 11:51:06 PM

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Bernd
Fireman



Posted - 07/16/2018 :  08:05:30 AM  Show Profile  Visit Bernd's Homepage  Reply with Quote
quote:
Originally posted by DanT

Ah! RMweb! I posted on this forum about 4 years ago, only to be dissed by a fellow American.


Ah yes Andy. I had a go around with him on MRH. I see he's no longer posting on any subjects on forums. I do know he has the Proto87 store. I read through quite a few pages. The conclusion I draw from all the negativism from the DCC guys is they are afraid a new control system will come along and make their hundred engine roster obsolete.


quote:
Fast charging LiPo's and the features the Qi Standard offers are really two separate issues. I think we both agree slow charging is the way to go. But how we charge can address issues of safety, efficiency and compatibility between devices from multiple manufacturers. The Standard provides a controlled charging process including shutdown when charging is complete. Nice to have IMO. I think consumers/modelers would want it as well.

Good luck with your project.

Dan


Since I'm not going to market anything I come up with, it's more of a fun "see if I can do it", I'm not to worried about standards. Although I do have safety in mind. Thanks for the good wishes.

I'm hoping that modelers reading this thread are getting some useful information out of this. This is usually how a product comes to market.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

DanT
New Hire

Posted - 07/16/2018 :  3:55:07 PM  Show Profile  Reply with Quote
What you're doing is priceless. It can influence the general thinking about induction charging and change the way we charge batteries. I understand shielding can influence the charging process as well as protect against unwanted EMF in adjacent circuitry, like receivers, maybe decoders. And I think I read somewhere that an iron core strategically placed in the void of a coil can also influence charging...so many variables, so little time to explore.

A heck of a weekend...one of the (rusty) bolts holding the tank to the bowl in our main bathroom broke causing UPF (Undesirable Puddle Formation). Was all set to work on magnetic induction, not puddle reduction. Replaced everything. Another reason model railroaders say their layouts are never finished? Back "on track" tonight...

Dan



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Bernd
Fireman



Posted - 07/16/2018 :  7:09:57 PM  Show Profile  Visit Bernd's Homepage  Reply with Quote
Thanks for the compliment Dan. I also read that some where. Once I get a better set up I'll give that a try. If I understood right the iron core concentrates the magnetic lines more. We'll see.

I had a bit of an accident too. Went out on the new patio last night forgot there's a step down once outside the door. I promptly went down on the hard surface and injured my left knee. I limping around with a cane.

So to day I got a Qi receiver in the mail. I'd ordered it from Adafruit, $14.95 plus shipping and of course NY state tax. Total came to $21.23. Reason I bought it was that the receiving coil would fit in the roof of an F7 if you cut down the sticky paper the coil is on. So I soldered on a pair of wires, fired up the 12 volt computer power supply, hooked up the transmitter in the first picture and the receiver to a multi-meter and NOTHING. Mmmmmm. Back to the Adafruit sight. Read the info:

"The driver chip is an integrated receiver called the BQ51013B from TI. Since its a Qi charger it can only be used with Qi transmitters! If you want a simpler inductive charger, check out our 5V charger set - it isn't Qi compatible but used together it works quite well!"

Should RTFM first. It's that "other charger I mentioned in the beginning of this thread. Here's couple of pictures of the board.





The reason I chose this wireless receiver was based on the width of the coil. It would fit into the roof of the F7. It's a perfect fit for any wide body engine. All I needed to do was trim the black backing the coil is on.



Another place that might be good to mount the receiver is on the bottom of the fuel tank. Perhaps even cut out the bottom of the fuel tank and mount the receiver to a piece of styrene secured to the tank frame.



That's it for now.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

jbvb
Fireman

Premium Member


Posted - 07/16/2018 :  8:50:47 PM  Show Profile  Visit jbvb's Homepage  Reply with Quote
I am not a genuine EE, but I've had enough physics to make me sure that mounting a coil against a conductive surface is going to change performance, probably for the worse.


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Bernd
Fireman



Posted - 07/17/2018 :  06:44:59 AM  Show Profile  Visit Bernd's Homepage  Reply with Quote
quote:
Originally posted by jbvb

I am not a genuine EE, but I've had enough physics to make me sure that mounting a coil against a conductive surface is going to change performance, probably for the worse.



There would be two ways to mount it. On the bottom of the tank. Mill out the bottom, add a plastic floor to mount the coil to. Take a look here: http://www.clag.org.uk/battery-radio.html Scroll down till you see Bachman Class 24. You'll see they drilled a hole in the frame to mount the coil in.

It'll be part of my experiment to see where best to mount a coil. I'm open to suggestions. Thanks for the post.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

Bernd
Fireman



Posted - 07/17/2018 :  07:39:33 AM  Show Profile  Visit Bernd's Homepage  Reply with Quote
I tried an experiment this morning. I was wondering if I could use the coil from the Qi wireless receiver on the first receiver I had bought. What did I have to loose. Fired up the soldering station and had at it. Here's the result.



Applying 12 volts to the transmitter yielded 6 volts on the receiver at approximately .250 inch gap. Not impressive, but it shows that the coil can be of a different shape and probably wire length. Next experiment will be to roll my own coils. Meaning both transmitter and receiver. With the different spaces in different engines, custom wound "working" coils would be a plus.

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

Bernd
Fireman



Posted - 07/17/2018 :  1:23:47 PM  Show Profile  Visit Bernd's Homepage  Reply with Quote
Looks like I may not have to roll my own coils. While searching for wireless charging circuits I ran across this web site.

https://sites.google.com/site/ddmcintosh2projects/inductive-charger

If you scroll down to near the bottom you come on a picture of a coil just like the one on the Qi receiver I have. The product is the Vishay IWAS4832FFEB9R7J50 receiver coil. I ordered two from Digikey. One for the transmitter and one for the receiver.

https://www.digikey.com/products/en?keywords=Vishay%20IWAS4832FFEB9R7J50%20

Bernd


A PESSIMIST sees a dark tunnel
An OPTIMIST sees light at the end of the tunnel
A REALIST sees a freight train
The LOCOMOTIVE ENGINEER sees three idiots standing on the tracks

Country: USA | Posts: 2677 Go to Top of Page

wvg_ca
New Hire

Posted - 07/17/2018 :  2:37:45 PM  Show Profile  Reply with Quote
the price on the charging coil isn't too bad .. 6.73 canadian in single quantities

regards, Warren

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