AC-to-DC adapter for controller - Page 2

gRC · #16 10-06-2002, 05:46 PM

Quote:

Originally posted by Nightwing
This allows you to keep a set of battries in the unit but when you plug in with an adaptor it cut out the battries and switches over to the adapter for you.

But removing the batteries makes the controller so much lighter.

I really was not sure how to wire a coaxial mount with switch. Perhaps someone could explain how.

Nightwing · #17 10-06-2002, 06:35 PM

But you must remember to remove the battries if you plug in or replace them when you are not running line.

Basically simple to wire. Two pins break one of the voltage leads and the other connect to the other non broken connection.

As always this is at your own risk.

There are three terminals to a power jack.

Center Pin { Inner ring }
Shield { outer ring }
Normal closed switch contact.

Simply break, cut whatever the ground wire from the battery box. { black lead }. Connect that to the "shield" terminal on the jack.

From the "Normaly closed switch contact" connect to where you broke the ground wire loose with a new black wire. Use a decent size wire.

Last connect the Center Pin to the plus wire { red } on the battery box. DOnt disconnect anything just attache it along with the current red wire.

You could add a diode in line just in case you reversed the voltage from the adapter to protect the controller.

Will wipp up a picture diagram later.

PS: As always check you hookups with a volt meter after you wire thing up. Just mak sure it disconnect the ground from battery box.

gRC · #18 10-06-2002, 09:40 PM

Here is a picture of the jack. It has three terminals: one on the left, one in the middle, and one on the right. Could you name each terminal according to its location in this image?

Nightwing · #19 10-07-2002, 12:28 AM

Love visual immages. Always worth a 1000 words!

Ok looking at that picture starting from the left:

The left most tab is "Center Pin".

The middle tab is "Shell".

And the one on the right is "Normaly closed switch contact".

Here is a crude diagram as if the transmitter case is open and you see the battery compartment. Note that the jack is not where it could go. Would recomend like another site to have it in the bottom but can be places whever it can fit without shorting out.

And as usual at your own risk.

gRC · #20 10-07-2002, 01:36 AM

Quote:

Originally posted by Nightwing
Note that the jack is not where it could go. Would recomend like another site to have it in the bottom but can be places whever it can fit without shorting out.

One of the reasons why I used the submini jack instead of a coaxial jack is that it is very small and fits easily next to the battery compartment.

Thanks for the diagram.

Nightwing · #21 10-07-2002, 01:50 AM

No problem!

If I was to mount it, I would put it in the bottom. But that me.

Good luck!

Nightwing · #22 10-09-2002, 11:55 AM

Nice diagram!

As long as the two jacks match should have no problem.

Just make sure the negative and positive of the wall wart matches with the wiring of the jack.

Good job.

Mattydiah · #23 10-09-2002, 12:10 PM

Im seriously considering doing this mod this weekend, my only question is, what voltage/amperage should we be using for an adapter? I dont think that was ever decided for sure.

EDIT: Ok, now that I re-read, has it been decided that the 800mA adapter is the best?

gRC · #24 10-09-2002, 02:19 PM

Quote:

Originally posted by Nightwing
Just make sure the negative and positive of the wall wart matches with the wiring of the jack.

There is an easy way to tell. When I accidentally reversed the polarity, the controller's green LED would not light up at all. After I correct the polarity, it would light up normally.

Quote:

Originally posted by Mattydiah
EDIT: Ok, now that I re-read, has it been decided that the 800mA adapter is the best?

I am still not sure about which adapter is the best. The 800mA adapter seems to closely match a pair of AAA alkaline batteries in terms of voltage when charging the car. However, I have not measured the actual amperage when charging because I don't have the proper equipment to do so. If the amperage of the adapter does not match the amperage of the AAA batteries, then the charging may be affected in some way.

Mattydiah · #25 10-09-2002, 05:49 PM

Quote:

Originally posted by gRC
I am still not sure about which adapter is the best. The 800mA adapter seems to closely match a pair of AAA alkaline batteries in terms of voltage when charging the car. However, I have not measured the actual amperage when charging because I don't have the proper equipment to do so. If the amperage of the adapter does not match the amperage of the AAA batteries, then the charging may be affected in some way.

Well, would it be safe to use a higher mA charger, or would this burn something out?

Nightwing · #26 10-09-2002, 06:24 PM

That is a good queston. When I droped the car on my test bench PS and saw it was 750ma was intersting. Glad it only for 45 seconds! Oh that bench supply can crank out 1.5amps at 15v.

Since its current that does the charging and how much you feed the battery set how long it need to get back a working voltage. Also this fast charge will cut the max charge cycles you can have on the battery almost in half.

For graphs on discharge rates check back on page one of this thread. I posted links to Duracell for both AA & AAA alk battries specifications and discharge rates and times.

If you feed too much current too quicky there is the risk of heating the chemical in the cell to where it could explode! Or if you draw too much can also casue problem form the host cells.

Between the .2 ohm resistor and Q4 I would think they would melt before too much more current flows.

gRC · #27 10-09-2002, 10:12 PM

I borrowed a multimeter that can measure up to 20A (i.e. 20,000mA) of current, and I measured the amperages of various power sources for the controller. The amperages were measured during the first several seconds when the car was placed on the charger, and sometimes the amperages gradually decreased while the car was being charged. The conductor in the controller's battery compartment is the location where the amperages were measured.

1.11A with fresh Duracell Ultra AAA alkaline batteries
1.04A with fresh standard Duracell AAA alkaline batteries
1.01A with fresh Ni-MH AAA rechargeable batteries
0.45A with depleted Energizer AAA alkaline batteries

1.23A with 3V 1000mA adapter
1.14A with 3V 700mA adapter
1.12A with 3V 2500mA adapter
0.95A with 3-12V 800mA adapter
0.49A with 3V 200mA adapter

Except for the 3V 2500mA adapter, these adapters produce more current than what they are rated for, which may be a concern. Right now I am leaning towards the 3V 1000mA adapter because of its compact size (with a folding AC plug) and its relatively high amperage rating.

Nightwing · #28 10-09-2002, 11:31 PM

Hum. May need to break out a remote voltage/current sensor. It can take mutiple voltage reading every .1 second. Be fun to chart it!

Cant do that untill this weekend or next Wed.

gRC · #29 10-11-2002, 12:16 AM

This time I measured the voltage and amperage of the actual charger while the car is being charged. The charger's conductors are located on the top of the controller, and they connect to the bottom of the car.

1.7V and 0.94A with used Energizer AAA alkaline batteries
1.8V and 1.07A with fresh Duracell Ultra AAA alkaline batteries
1.8V and 1.24A with 3V 1000mA adapter

In all three cases the voltage and amperage fluctuated slightly while charging. I may post some charts later that show the voltage and amperage over time.

gRC · #30 10-11-2002, 12:40 AM

One thing I noticed is that the car seems to run longer if I use the 3V 1000mA adapter while charging the car. I suspect that the higher current output of the adapter causes the car to be slightly overcharged, which leads to a longer run time. I will try to confirm it later.