Automatic Charge Station (ACS) - Page 4

Steve · #46 03-12-2003, 09:52 PM

lots of good ideas, but as mentioned early on in this thread, and from what I've learned from trying different things myself (see below)...it seems you really need to have pressure on the charging points in order to get a reliable connection. How?

My latest attempt was a piece of track (balsa wood) that had holes that lined up with the rear wheels of the cars. When the holes where open, the rear end would drop the car onto the charging posts. With rails in place, it was easy to hit and various model cars would drop consistently onto the contacts, but sometimes it would charge, sometimes it wouldn't grrrrr. When it failed to make contact, just a little vibration (spinning the rear wheels) would get it going, other times it would take a little tap on the track with a finger. So what's a guy got to do, build a vibrator into his pit lane...? Bummer.

BenCloned · #47 03-13-2003, 02:09 AM

In my design (posted earlier in the thread) the weight of the rear of the car levers the charging points into place.

Squishy · #48 03-13-2003, 04:23 PM

It seems there are a ton of ideas in this tread would work if not for one thing, CONTACT. Stupid contact! GRRRrrrrr. Altough, bencloned has a good idea there, but i am still alittle skeptical about contact. Some one give it a try! Heck, I am probably goin to try my own now!

ph2t · #49 03-13-2003, 07:12 PM

How about this....

Using the principal of induction, you could transfer the electricity from the charger to the car using coils. Once half of the circuit would sit at the back of the car with a coil exposed. You would back up the car to the charge station and the current would be exchanged from the charger to car using the magnetic field of the AC current. The circuit on board the car would then rectify the current into DC and with this you could charge the battery.

I know this is a "way out there" idea, hell I don't know if it would even work,

but it solves the problem of requiring contact. You would probably need to make your own coils using some very fine enamelled wire. Also the circuit on the car would need to be able to regulate the charging voltage and current (say 1.5 - 3V @ approx 100 - 200 mA) so in the end the circuit might be so big as to make the whole idea not feasable.

Hell, I wan't to try this out now....

See the circuit pic below.

Cheers,

ph2t.

#50 03-16-2003, 12:58 AM

my thought would kinda be a bit extra and maybe not what youre going for but what i was thinking was using one of the many ideas in here with my bit....using the steering magnet as the pull, and creating an elctromagnet on the platform that is activated by a remote button, be it an extra controller, or something however you could work it. so when you pull up over the contacts with the funnelled rails and want to charge, hit the remote button, elctromagnet turns on, pulls car solidly onto contacts and then push button again to release car and off you go. maybe thats to simply or not what youre looking for, but i just thought i'd put it out there for scrutiny. good luck dude

Steve · #51 03-16-2003, 08:40 AM

Quote:

Originally posted by -v2oracle-
my thought would kinda be a bit extra and maybe not what youre going for but what i was thinking was using one of the many ideas in here with my bit....using the steering magnet as the pull, and creating an elctromagnet on the platform that is activated by a remote button, be it an extra controller, or something however you could work it. so when you pull up over the contacts with the funnelled rails and want to charge, hit the remote button, elctromagnet turns on, pulls car solidly onto contacts and then push button again to release car and off you go. maybe thats to simply or not what youre looking for, but i just thought i'd put it out there for scrutiny. good luck dude

The only problem I see is that the electromagnets are in the front, so it won't hold the back down...or at least I don't think it would. However, the idea might be used to rock the car on the charging terminals to get a good connection...I may have to try this.

Azimov · #52 06-13-2003, 01:30 AM

Hey all. I've been looking over this thread and thinking about all the replys and I have some ideas. First, I don't like the backing into the charging station. This would delay races and be a hassle. I think the way to do it is a seperate charging lane along side the track that the cars can slip into. One on each side like pit lanes. Make them narrow so only one car width can fit, Make them around 18 inches long with two metal strips running on the ground for around 12 inches. Put the contacts on the bottom of the car, spring loaded like pick up shoes, but not low enough to touch the track so there is no drag durring racing. Raise the two metal strips slightly off the track so the shoes will make contact when the car is driven over them. The metal trips would also work like mini rails to help guide the car. This set up would allow driving in, stopping and charging and zipping out again. The problem of stopping at a precise point is eliminated as you have a foot of room to stop during contact. The springs in the pickup shoes will allow for firm contact and the charge process can be done just like a quick pit stop at Daytona. Whattaya think?

ph2t · #53 06-13-2003, 01:52 AM

Good idea but the main problem is getting enough pressure in the contacts to sustain the current needed to charge the car.

ph2t.

Azimov · #54 06-13-2003, 03:09 AM

Quote:

the main problem is getting enough pressure in the contacts to sustain the current needed

Well, lets see. Slot cars do this all the time. They use brass pick up shoes and steel rails. The pick up shoes have springs aligned straight down to help keep contact. These springs should be conductive and ride in the Zip's existing chassis charge holes. Now, the problem is, slot cars have more juice going between the contacts which helps the transfer quite a bit.
So, we could make the shoes out of steel as well as the springs like the track charging rails. Magnets could be placed under and in contact with the track rails to magnatize the rails. This would pull the spring loaded and retracted pick up shoes down to the rail when the car comes over. This could also be done more elaborately with an infrared sensor that trips an electromagnet to magnatize the rails, charge, and release through peak sensing circuitry. But, I think a couple of good fridge magnets might do the trick.
Still, the original idea might work, just like slot cars. The magnets could be added if the prototype isn't making good contact. Uping the current might help the contact and make charges much quicker.

Azimov · #55 06-13-2003, 04:40 AM

Something like this rough sketch.

ph2t · #56 06-13-2003, 06:18 AM

Brillilant picture man, you have an eye for detail... If the car is heavy enough to be able to offset the spring whilst it's in compression I believe you have a working solution.

An idea: Construct a circuit that will sense the car on the rails by either voltage dip (car's contacts connected) or IR. This will then trigger a timer that turns on an electromagnet to hold the car down, ensuring a healthy contact. For this period the car will charge and at the end (eg: 45secs) be released from the magnet, and take off down the track.

You could do this with a 555 timer and a few transistors. You would also need a custom charger .

ph2t.

actofgod · #57 06-13-2003, 09:56 AM

Yes, "rough sketch" is humorous. It's freakin' artwork, Azimov

Wow, great ideas here. I love the rails. Ph2t, the electromagnet/timer combo is snazzy, but will you always want to do a full charge? What if you only have one lap left and just need a small charge so you can finish? I'm in the KISS camp, so I'd stick with the fridge magnets underneath and wire an LED into the rail circuit. It could come on whenever the car was charging, so you'd know if you needed to move the car a little to get a better contact. You could leave it charging as long as you wanted, from just a short boost to a full charge. If you wanted to get fancy, you could have a digital timer display that counts while you charge, but counting seconds in my head works for me

Oh, and you'd really need several pit lanes I'd think.. at least two. Otherwise, a car with only a couple seconds lead time over the next would get to the charger first; the second car would have to wait around while the first charged and then do its own charge, so the first would end up with a 45-sec lead.

Azimov · #58 06-13-2003, 01:08 PM

The only problem I see with this system is that the cars would need to be physically modified. This isn't what the owner of the post wanted. I'm not sure how removable shoes could be made to snap onto any car.
The track part is easy and I have a pit lane like this on my track that I may convert. I agree that you would need at least two lanes, but I have one lane now that could serve as a guinie pig. A minor concern is whether the metal rails will foul the car's steering. This may not be a problem as the rails will also guide the car through the charging lane. If a real problem, this could be solved by making the rails and shoes out of brass. This assumes of course that the magnets aren't needed.
This would be a fun little experiment. But, two cars would need to be permanently modified to make use of the charging system.

tinyrc · #59 06-14-2003, 12:03 AM

Quote:

Originally posted by Azimov
Something like this rough sketch.

Awesome diagram, and awesome ideas! I particularly like the TRC sponsorship, a must for every track!

Azimov · #60 06-14-2003, 12:20 AM

Quote:

I particularly like the TRC sponsorship, a must for every track!

Oh yes, gotta have that!
BTW, the induction charge idea is a sound one. There is a pad I've seen on the market that will charge anything placed on it that contains rechargeable batteries. I saw it on a news site. It looks like a rubber pad about the size of a notebook. You just throw your cell phone, or any other chargable device, onto the pad and it automatically charges it through induction. I don't know how much it cost, or if it can be cut up into a track lane. But, the principle is sound.
I think I may try building a prototype of the system I diagramed. I think it will work and beats putting built in charge pads into my pit area, which was my original idea. If I do build it I'll post the results for all to see. And, of course, credit goes to the thread owner for having such a stroke of genius like a "on the fly" charging system in the first place.