PDA

View Full Version : AC-to-DC adapter for controller


gRC
10-04-2002, 10:57 AM
I mod'ed my ZipZaps controller last night to use an AC-to-DC adapter. Basically I opened the controller by removing the screws, drilled a 5/32" hole next to the left side of the battery compartment, and mounted a 3/32" (2.5mm) submini jack (Radio Shack part #274-245). I am using an AC-to-DC adapter rated at 3V and 200mA with a submini plug (#273-1708, Adaptaplug E). For safety I remove the batteries before plugging the adapter into the controller.

This mod seems to be working well. The controller has the same range as before (if not better), and the car is fully charged in the same amount of time. Furthermore, its performance will most likely be more consistent because there is no battery drainage to worry about.

I may post pics and more detailed instructions later if there is interest.

One question: Would there be any benefits in using an AC-to-DC adapter that has a different rating for voltage and/or milliamps? Or are 3V and 200mA really good enough?

JediYoda56
10-04-2002, 11:14 AM
Now if you could do a AC-to-DC adapter for car for the car that would be awesome. Limted range but think of the power! :eek: haha

Namuna
10-04-2002, 11:23 AM
Yet again the gRC comes through with the goods!

As far as voltage/amperage goes...I'd say you're dead-on for the voltage at 3v (since it takes 2x1.5 in series AAs).

I'd think you could probably go higher than 200mA though, but the only way to be really sure is to pull out the trusty MultiMeter and check the current with the standard AAs and go from there.

Good work gRC!

Axel
10-04-2002, 12:20 PM
I've been wondering this too... would it help the controller to put more than 3V into it? It makes the car go faster, so would it make the controller throw a stronger signal?

Has anybody tried putting more juice through the controller yet?

gRC
10-04-2002, 12:50 PM
Originally posted by Namuna
I'd think you could probably go higher than 200mA though, but the only way to be really sure is to pull out the trusty MultiMeter and check the current with the standard AAs and go from there.
I have not tried the multimeter yet, but I have noticed that the red LED is dimmer when charging if I use the adapter instead of fresh AAA batteries. So I probably could use an adapter that has more milliamps.

Nightwing
10-04-2002, 02:00 PM
Maybe this will help.

A standard set of AA battries should give you around 450ma. Not sure but I think AAA should be around 300 to 400.

Namuna got it right. Grab a fresh set of battries. Measure just idle current. The measure charging the car. Also note voltage level doing both.

Unless that has a regulator in it, most wall/floor warts transformers consist of a step down transformer one to four diodes and a filter cap. IE they dont have constant voltage for 0 to max current and a nasty ripple. Sometimes I have seen 2 to 5 volts higher on light load. The voltage is normal what is rated when at or near the rated current.

May want to get a higher voltage and regulate it down to 3v. This will clean up the voltage and make it more like a battery.

Namuna
10-04-2002, 02:09 PM
Ooof, good point about the 'ripple' NW!

What do you suggest as a means to regulate a higher voltage adapter down to 3v?

Nightwing
10-04-2002, 03:36 PM
RS sells a adjustable one #276-1778 can hit 3 v and regulate about 1 amp. Takes one or two fix resistor, a pot and two caps. I recomend some electrolitics over the disk caps they show. Around 100mf on output and same on input or something close. Since you want 3v out should feed it with about 4.5 to 5 or more. If you feed it with more than that add a heatsink to let it get rid of some of its heat it will burn off to get it down to 3volts.

brianpipa
10-04-2002, 05:14 PM
I was just thinking baout this today. Yes, PLEASE post detailed instructions so I can do this too! :)

brian

Nightwing
10-04-2002, 09:39 PM
Hum... RS does not sell a decent size heat sink any more! :mad: Could use some PC board copper as the ground and heatsink. I have almost all the componets in stock but want to get some RS same parts to make it easy to duplicate.

Also notice that RS has a 3v 700ma filtered and regulated adapter for 14 dollars. Will grab one and check it out but will come up with a simple list and instruction on a filter for a unregulated one. :)

gRC
10-05-2002, 03:18 PM
I picked up several 3V adapters from Radio Shack to try out. They are candidates to replace my seemingly inadequate 3V 200mA adapter.

I first used my digital multimeter to measure the voltage and amperage of a fresh pair of AAA batteries in the controller. When the controller is turned on but not charging, the batteries produce 3.00V and just 7.5mA. When the controller is charging the car, they produce 2.48V and possibly over 200mA. My multimeter cannot measure amperage over 200mA, but it would occasionally display measurements in the range of 190mA to 199mA, which may or may not be significant.

The table below shows the voltage measurements for the various AC-to-DC adapters. The fields are as follows: voltage when not charging, voltage when charging, Radio Shack part number, price, voltage and amperage rating.

3.66V 1.92V 273-1661 $XX.XX 3V 200mA
3.19V 2.44V 273-1667 $15.99 3-12V 800mA (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F004%5F001%5F001%5F000&product%5Fid=273%2D1667)
3.20V 2.82V 273-1756 $16.59 3V 700mA (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F004%5F001%5F001%5F000&product%5Fid=273%2D1756)
3.18V 3.02V 273-1754 $19.99 3V 1000mA (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F004%5F001%5F001%5F000&product%5Fid=273%2D1754)
3.14V 3.00V 273-1695 $19.99 3-6.5V 2500mA (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F004%5F001%5F001%5F000&product%5Fid=273%2D1695)
3.83V 2.58V 273-1755 $13.99 3V 500mA (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F004%5F001%5F001%5F000&product%5Fid=273%2D1755)
4.04V 2.20V 273-1662 $14.99 1.5-12V 300mA (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F004%5F001%5F001%5F000&product%5Fid=273%2D1662)

I noticed that the red LED looked different depending on which adapter was being used for charging. With the 200mA adapter it appeared dimmer than usual. With the 700mA, 1000mA, and 2500mA adapters it appeared orange instead of red because the green LED was slightly lit at the same time. With the 800mA adapter it appeared the same as with the AAA batteries. Therefore, it seems that the appearance of the red LED is related to the voltage when charging. However, I am not sure if it is better or worse to have a charging voltage that is lower, higher, or the same as that of the batteries. I assume that having nearly the same charging voltage would be ideal, as is the case with the 800mA adapter. One advantage of the 800mA adapter is its variety of voltages for other devices, but one disadvantage is that it is the largest and heaviest of the adapters.

If someone is able to measure the actual amperage when charging, I would be interested in that measurement.

I plan to post pics and detailed instructions of the mod later.

Edit: I measured two more adapters and added their voltage measurements to the table above.

gRC
10-06-2002, 02:41 AM
For what it's worth, I replaced the regular Duracell batteries with a fresh pair of Duracell Ultra batteries and measured the voltage again. When the controller is turned on but not charging, these batteries initially produce 3.16V and then gradually drop to around 3.0V as they are being used. When the controller is charging the car, they initially produce around 2.8V and then gradually drop to around 2.5V.

Nightwing
10-06-2002, 02:23 PM
Drop my little friend on a adjustable bench supply. Wow that thing draws current! It went to about 750ma at around 2.87v while charging. Sheech! :eek: Q4 is getting a workout!

Just for giggle here are the spects on Duracell stock Alk battries:

AAA
http://www.duracell.com/oem/Primary/Alkaline/mn2400.asp

AA
http://www.duracell.com/oem/Primary/Alkaline/mn1500.asp

I think that a std set of battries wont do 750ma. Both on voltage drop and that much current being drawn. Need to pop a line and measure.

Looks like the 800ma 3v will go back and need to design a pritty good heatsink for the adj regular version. At least it can take 1.5amp max.

gRC
10-06-2002, 03:55 PM
I created a web page with several pics of the mod.

AC-to-DC adapter mod for ZipZaps controller (http://home1.gte.net/res18h39/adapter/)

Nightwing
10-06-2002, 05:16 PM
Nice job.

RS does offer a Coaxial DC Power Jack with switch. 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. It also makes it hard to pull out, more robust, does not short the adapter pluging and unpluging and give better contact.

If you go with this, use 274-1583 for the jack 273-1717 for the adapter on the transformer. Or whatever combo fits well. The jack is a case mounted one so you only need to drill a hole.

gRC
10-06-2002, 05:46 PM
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
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
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
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
10-07-2002, 01:36 AM
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
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
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
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
10-09-2002, 02:19 PM
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.
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
10-09-2002, 05:49 PM
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
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
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
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
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
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.

Nightwing
10-11-2002, 01:19 AM
One thing would be is if the bat gets hot. If it gets too hot you can and will have an explosion.

If you want to use a volt metter alone instead of a amp meter just measure across R15 the 0.22ohm resistor. Use the old current/voltage/resistance formula to find for current.

I = E/R

I= Current in amps.
E= Voltage in volts.
R= Restance in omhs.

So it would be:

I = ?/.22 With ? as the voltage measured.

Its the same as the shunt in the meter you are using but wont affect the circuit with added resistance.

Since charging any batter is how much current vs time you apply I am leaning back to the circuity, AAA battries and timer have been picked to keep from blowing the battery, car etc up. IE the circuit IS the fuse! :eek:

Oh here is the spects on the Q4 transistor:
http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/a6717b3819c6a23485256a1c00529259/9f3fcef8c90ab9ea85256a78007bb529?OpenDocument

Click on PDF spects to see max values etc.

Warnning! Even though the spects are for a generic replacement, that little transistor absolute Max Ratings collector current is 1 amp constant and 2 amp peak! So the 750ma makes sense.

A good friend thats delt with more PS than I will ever know, passed some info on a company that has some special charging IC. Since people are hyping up their cars, may be worth looking for a better charging circuit to replace this one.

So for those with fresh battries but cant charge could be that either or both the Q4 and R15 got tosted.

Mattydiah
10-13-2002, 01:02 AM
Ok, I will be attempting this mod in about 10 minutes. I bought all the stuff at radioshack today. I got the coax jack and the 3V 1000mA adapter, but I found out you dont have to buy a plug to go in the adapter. Radioshack gives away a free adaptaplug with every power adapter, and it turns out that Adaptaplug "M" (PN. 273-1716) will work with the Coax power jack (PN. 274-1582).

No big deal, but it will save you a few bucks if you are doing this mod.

Mattydiah
10-13-2002, 02:09 AM
Well, I just finished this mod. Took me slightly under 20 minutes to do. It is very easy if you follow the picture that magz provided on page two.

Now, instead of glowing red when charging, my controller glows orange from the extra voltage!! It gives the car more low end punch, and seemingly extended battery life. Plus, the best feature of all, now the batteries in the remote only get used for controlling the car, not charging it, (since inserting the adapter cuts off the batteries) which I'm sure will make a big difference in battery life. One more thing, now you never have to worry about your car being slower because of dying batteries!!

Very good mod!! I recommend it to anyone with soldering ability!

joeNuggetz
10-20-2002, 09:35 AM
but what would one use for a 4.5 volt mod?

spradlinb
10-22-2002, 11:30 AM
Definitely a great mod, and the picture of the inside of the controller with the wires hooked up was perfect for me to work out where to solder! My Micro Q controller now has power from a wall jack and works perfectly. Unfortunately, I only had one of the jacks left in my parts drawer, and when I went in to RS for another pack I found that they have reorganized and removed a HUGE section of their electronics parts selection. Needless to say, they no longer have the sub-mini jacks I need, and neither does their online website. I guess I just won't be adding this mod to my ZZ controller after all :(

Cheers.

gRC
10-23-2002, 10:11 PM
I recently redid the mod using jacks with switch so I don't need to remove the batteries. I follow Mattydiah's advice to use the adapter for charging especially. Thanks to everyone for contributing to this thread.

Nightwing
10-23-2002, 11:54 PM
spradlinb, you mean they are not stocking Power Jack#274-1583 and plug #273-1717?

spradlinb
10-24-2002, 08:27 AM
Originally posted by Nightwing
spradlinb, you mean they are not stocking Power Jack#274-1583 and plug #273-1717?

They still have those parts online, but you can only find them if you do a search for those specific part numbers... they don't appear in their "categories" anywhere on the site, which is yet another reason I really don't like their website. The store in town doesn't carry them anymore either, as their parts have been cut down dramatically in the last week. Where there used to be two small cubicle walls full of electronics parts there is now a dresser-sized box with a few generic parts in large drawers instead.

I was actually using a different power jack, a sub-mini jack that's much smaller than the part you used but still has the on/off switch inside it so that I could keep my batteries installed while charging. It uses the power plug that looks like a small headphone plug, for those that don't know about it. I don't have the box it came in anymore for the part number, and I already mentioned how "helpful" their website is... I guess I'll try again later to see if they get new stock in since they're still rearranging stuff in the store from the change.

Cheers.

Nightwing
10-24-2002, 12:16 PM
Like you had to go digging in their new storage system. I know the people working they are getting tired of this almost constant rebuild. It getting tiring going around boxes to get to stuff.

It looks like they are dropping the smaller jack. I hope they dont totaly drop parts even though that is a hight thief item.

Hum. Wonder if this would be a nice item for the sites that stock speed parts for Bits/ZZ? The wall warts would be a local pickup item but the jacks could be offer on site. Just an idea.

hawaiiboy
10-28-2002, 04:06 PM
I am new to this Micro RC thing and after burning through $20 worth of batteries in 2 days I figured I would try this AC adapter mod. It worked great yesterday after I finished but today when I tried to charge my ZZ it began acting alittle peculiar. The light blinked off when I attached the ZZ to the charger then came back on and remained green, I played around with the connection and it started blinking green. Any idea what this could mean? If I try to charge it with just the batteries and it workes fine. BTW I used the switched plug to avoid having to remove the batteries....any help would be great.

gRC
10-28-2002, 05:11 PM
Originally posted by hawaiiboy
Any idea what this could mean?
I'm not sure. I have never seen a problem like that.

What are the voltage and amperage ratings of your adapter? Perhaps the adapter is faulty.

hawaiiboy
10-28-2002, 08:39 PM
After making the first post I tried a few more times and it still didnt work, however after about 45 mins I tried it again and it worked normally. I got the recommended 3v 1000ma rs#273-1754.

On a hunch I got up and went and tried it again just now (the experiences above were about 4 hours ago) and it did it again, blinked off green and then solid green about 3 times and the fourth time it went to red and it seems to be working fine.

I guess I will open it up and maybe check for loose connections. _

Nightwing
10-29-2002, 12:28 AM
Some questons.
Does the power plug fit snug in the jack?
Double check the solder connections.

grimoire
11-04-2002, 08:38 AM
It appears to be clear that this mod is a great way to enhance my enjoyment of my ZZ with respect to chargin' that sucker up (esp if I also go with the 2.4V dual batt mod).

Here's another question tho...does this increase the range of the controller any? In other words, if I leave this puppy plugged into the wall while I'm driving my 27MHz Porsche around, will it cause the transmitter in the controller to pump out more power?

I've already added at 17 3/4" antenna to my controller, which increased my range quite nicely. But, I'm greedy ;)

Nightwing
11-04-2002, 08:58 AM
That would be greate but sorry its does not add one inch to range. :( It may act like a ground wire { Helps ballance the signal from the antenna } but does not increase range. :(

grimoire
11-05-2002, 06:26 AM
Let me start off by saying that I know next to nothing about electronics (if you haven't already guessed that ;) )...

I noticed in a couple of other threads that some folks claim that adding extra batteries to their controllers increased the range. One poster said that adding a 3rd AAA battery almost doubled the range. Are other folks who have made "extra battery in the controller" mods seeing the same effect?

Now, I assume that the mod for the AC adapter we're discussing is aimed at just increasing the power to the charger (right?), but would it be possible to do this mod in such a way that extra juice is pumped into the controller's PCB too (keep in mind that I already said I don't know anything about electronics)? If that isn't a non-sensical question, would that be a bad thing to do? Would it actually do anything to help the range?

Thanks in advance for any advice...I gotta say that one of the main things I love about my ZZ is mod-ing it!

Nightwing
11-05-2002, 06:52 AM
The AC adapter mod is basically replaces or suplement the two AAA bats in the controller.

If you jack up the voltage { dont go above 5v } you can get a bit more range. Simply making the circuit run more hotter so to speak. Its a old trick to get a bit more signal was to increase the voltage to a tube final but would burn out the tubs much faster.

The one limited componet is rated to 5v. But the charge circuity is designed for 3 volts.

grimoire
11-05-2002, 07:03 AM
Thanks for the prompt reply, Nightwing!

So, if I used a 4.5V adapter, I might see a boost in the range (but probably not "double")? I'm thinking about the 4.5V because I'm also considering doing the "no car modification" dual-battery mod mentioned in another thread, and that thread's discussion leads me to believe that 4.5V is probably a more appropriate voltage to charge the 2 batts in series.

I'm a pretty slow deliberater, so it may be weeks before I get around to doing either of these...this is my first RC car (at over 40 years old, I'm definitely a slow starter), and I'm fond of it and afraid of breaking it :D

Nightwing
11-05-2002, 07:28 AM
No problem. Glad to help. :)

You may see a bit of an increase but not double. Actualy increasing the antenna wire on the car and a longer antenna on the controller would be better.

Actualy its current that charges a battery. As long as you have enough voltage potential to shove current to the battery your ok.

Good luck on the mods! :)

grimoire
11-18-2002, 03:01 PM
I added an 800ma adapter switchable between 3V and 4.5V. Definitely increased my range (probably because the current is greater than 2 AAA batteries ever provided).

An interesting test...when I ran the adapter at 4.5V, I got about 10% more range than at 3V.

Nightwing
11-18-2002, 10:19 PM
Basically you are increasing the voltage to the "final" transistor which up the wattage which increases your range. Cute huh! :)

Just dont go beyond 5 volts or you will fry the IC that generates the tone codes. It maxes out at 5 volts.