Circuit Design Help

[Ronald_raygun]

Ok, I mulled it over a bit and came up with the following circuit. (See attachment)

The toggle switch on the right is meant simply to arm/disarm the car itself so I can't have a false start without first arming the car.

The two wires on the right lead to the charging station. The charging station is simply a battery pack with a regulated 3v going into the system in order to charge the fuel cell.

I wasn't sure where to put the normally closed momentary switch. I figured as close as possible to the motor was best. Is that necessary?

Other than that, I think I'm set. I used ExpressSCH for circuit (http://www.expresspcb.com/ExpressPCBHtm/Download.htm)

One last thing. Is there anything wrong with this circuit? Will it perform as I want it to perform?

[Alan Anderson]

Originally Posted by Ronald_raygun

...I wasn't sure where to put the normally closed momentary switch...Is there anything wrong with this circuit?

The purpose of that switch is to interrupt the power to the relay coil and permit it to turn off. It should be placed between the Normally Open relay contact and the coil. It would also work if placed between "+" side of the fuel cell and the common relay contact, or if placed between the other side of the coil and the "-" side of the fuel cell.

By the way, I'm a little confused about what the "fuel cell" actually is. You're describing it as something which needs to be charged from an external electrical supply, but my understanding of a fuel cell is that it uses chemical fuel to produce electricity, and gets "charged" by filling it with hydrogen or alcohol or some hydrocarbon.

[Ronald_raygun]

Ok, about the Fuel Cell, this is how it works.

The fuel cell is something called a Reversible Fuel Cell.

Namely, The fuel cell not only combines the hydrogen and oxygen to create electricity, but it can also separate it. The problem with this is that the fuel cell is about 40% efficient. For every joule of energy I put into the fuel cell, I can only get .4 joules out.

If you have any more questions about the fuel cell, feel free to PM me

[Al Skierkiewicz]

Jose,
The circuit should work except for the momentary switch in the motor circuit. That switch is redundant with the toggle switch just below it. You can wire the momentary, normally closed, switch in either lead of the relay and pushing it will release (open) the relay.

[Ronald_raygun]

Thank you Mr. Skierkiewicz and Mr. Anderson for your inputs. I'll go hunting around for parts which would work for my 3v system. Hopefully, I can get what I need out of this to make it work. I'll get back to this board with the results. (Digikey, radioshack, ugh...)

EDIT: On a completely random side, I'm working on a duct tape prom outfit with my date. We figured that we needed to be really shiny or otherwise bright at the prom itself. That led me to electroluminescent wire, also called glowire methinks. Anyway, how best should I attach the electroluminescent wire to the duct tape prom gear? Clear tape? Staples? Magic?

[Gdeaver]

You might look at Lynx technologies and their key chain transmitters and a receiver with a latching decoder chip. They're 3 volt devices.

[Al Skierkiewicz]

Jose,
I have seen Duct Tape Tuxedos, are reallly sure you want to do this for a once in a lifetime event? Some tapes are conductive so you have to be careful how and what you use for ligthing. There are a few companies that manufacture LED ropes and light bars that might work. Clear tape would be OK. I would think that a few well placed thread stitches would be OK as well but why not use mini tie wraps? If you are stepping over the line of fashion you might as well take a big jump over the line.