making a little power supply for some adb devices

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Joined: Jul 7 2005
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I was wondering if anyone had any comment on me taking an unused abd or svideo and strip a little 5V power supply to it?

likewise to power the supraexpress modem and connectix quickcam without worrying about overloading the actual adb port itself?

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Joined: Jul 7 2005
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I meant 'adb or svideo cable'

I meant 'adb or svideo cable' ugh!

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Joined: Jan 23 2005
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The SupraExpress modem...

The SupraExpress modems that I have here, already use external power supplies. The SupraExpress uses a 6VDC 480mA external power supply.

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I should correct one thing, t

I should correct one thing, the supraexpress modem I have is the mac-specific one that powers off adb port alone and it doesn't even have a dc jack on it.

hope that helped now

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Ah, okay...

Ah, good point. I don't own any Mac specific modems other than a bunch of internal Global Village comm. slot models and a USRobotics Mac & Fax. My two Supras are both plain old SupraExpress modems.

I really can't see that you'd experience too much of a problem with powering your SupraExpress from your ADB port. What else are you running on your Apple Desktop Bus? Just a keyboard and mouse?

You could wire up a simple little five volt supply to the SupraExpress and probably have no problems with it, but is it really worth the time and effort? If you're really that concerned about it, you'd probably be better off just splicing an on/off switch into the cable that draws power from the ADB port. I'm assuming that you'll be using your modem very rarely; you have a broadband connection, right?

A little common sense goes a long way when dealing with computers. The reality is that you are unlikely to improve anything by rigging up an external power supply for your SupraExpress modem. As a matter of fact, you haven't offered any evidence to even suggest that your 6300 may be experiencing undue strain as a result of power demands.

Just my opinion...

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well actually its keyboard, m

well actually its keyboard, mouse, and wacom tablet plugged in currently and I'm looking to add the supraexpress modem and that yet-to-get connectix quickcam in as well

just thought I could see if I could figure making the modem and quickcam onto their own power supply unless someone tell me these five devices altogether isn't going blow out the adb circuit on the logic board *hehs*

oh and I dunno about any broadband for where the system may be left at anyhow so hence the modem (plus especially for outgoing-only faxes too)

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What do you plan...

What do you plan on using your modem for?

Personally, I have two computers with internal modems, iMac & Performa 5200, and rarely ever use the modems. I have a cable broadband connection for the internet and all of the Macs that I use are on a network that shares the internet connection. The internal modem in the iMac never gets used and the internal modem in the Performa 5200 gets used very rarely for sending faxes.

I could load up one of my Macs with all kinds of stuff that would get very little use, but what would be the point?

The Performa 6300 used either a 100MHz or 160MHz 603e processor. We're not talking about a machine that can do some serious computing here. We're talking about a computer that is fine for playing games, word processing, simple graphics, and just barely able to surf the web with some decency. I mean, you can add all of these gadgets and doodads to your 6300, but it will never be the be-all-end-all Macintosh that you may be envisioning it will become.

Reality: By the time you get all of the drivers and control panels and applications installed to use all these gadgets, your 6300 is going to be so bogged down by a bloated System folder that power strain on your ADB port is going to be your last concern.

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actually I've packed the 6300

actually I've packed the 6300CD down a lot once (was testing the various scsi peripherals I had for once) and it didn't have much problem at all save the bootup time with useless extensions always still left on (being lazy anyway)

one of the minimal-ing trick I figured out was with using older quicktime version (not that metal skinned version which seem to use lot more resources) which worked well anyhow.

and I didn't really have any problem with netscape on it (save these certain sites that not surprisely would fail a fair validator)

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To answer the original question...

The ADB port is rated to supply 500mA (milliamps) maximum on the desktops, and 200mA on the laptops I've looked at. Any more load than that and you certainly run at least some risk of burning something out on the mobo.

As long as you have the pinouts right and label your powered plug clearly (so you don't go plugging it into a computer by mistake) I don't see any problems with your idea. You'd want regulated 5v and enough current for all your devices.

Annoying that the portables are downrated as that's the situation where you'd most want to do away with extra power supplies.

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thanks drbunsen, and as for t

thanks drbunsen, and as for the powerbook's 200mA rate I think this might had been a minor battery life saving idea and/or due to the fact the powerbook logic circuit was designed smaller sized?

as for the real theory of why...umm...I don't really know, maybe someone does?

one thing for sure still is that even 200mA is still enough for one external modem like the macintosh supraexpress one thou so I guess you ca't complain too much, no?

as for you saying "to do away with extra power supplies" I keep wishing for that so many times at particular times Tongue

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Re: thanks drbunsen, and as for t

pegasus wrote:

thanks drbunsen, and as for the powerbook's 200mA rate I think this might had been a minor battery life saving idea and/or due to the fact the powerbook logic circuit was designed smaller sized?

as for the real theory of why...umm...I don't really know, maybe someone does?

one thing for sure still is that even 200mA is still enough for one external modem like the macintosh supraexpress one thou so I guess you ca't complain too much, no?

as for you saying "to do away with extra power supplies" I keep wishing for that so many times at particular times Tongue

At the risk of sounding like an imbecile, why would you ask for advice on adding extra, albeit unnecessary, power supplies to the peripherals of your Performa 6300, only to close out your thread with the following:

Pegasus wrote:

as for you saying "to do away with extra power supplies" I keep wishing for that so many times at particular times Tongue

Managed Resistance shakes head and walks away in a daze...

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Re: At the risk of sounding like an imbecile

managed resistance wrote:

At the risk of sounding like an imbecile, why would you ask for advice on adding extra, albeit unnecessary, power supplies to the peripherals of your Performa 6300, only to close out your thread with the following:

Pegasus wrote:

as for you saying "to do away with extra power supplies" I keep wishing for that so many times at particular times Tongue

Because he has so many ADB powered peripherals that he's concerned about overloading the out on his 6300. Rightly so IMHO.

/edit/

Ooo, speaking of imbecilic, it's just occured to me that it's probably wise to make some provision to prevent any current going back into the port. Probably the simplest and safest way of doing this would be to cut an ADB cable in the middle, and then connect it back up without the +5v line to the Mac end. Instead, divert that line to your PSU. Make sure to label which end is which.

A salvaged PSU from an LC or an external drive box would be a cheap source of regulated +5v. The LC ones are fully shielded - safer. Or you could use an internal drive power splitter and run a +5V and ground line out the back of the 6300. Add a standard DC socket on the back, and plug your ADB thingymabob into that.

Might as well add a +12V/gnd socket while you're mucking about with the drive connector - eliminate another plugpack or two Smile

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Re: At the risk of sounding like an imbecile

DrBunsen wrote:
managed resistance wrote:

At the risk of sounding like an imbecile, why would you ask for advice on adding extra, albeit unnecessary, power supplies to the peripherals of your Performa 6300, only to close out your thread with the following:

Pegasus wrote:

as for you saying "to do away with extra power supplies" I keep wishing for that so many times at particular times Tongue

Because he has so many ADB powered peripherals that he's concerned about overloading the out on his 6300. Rightly so IMHO.

/edit/

Ooo, speaking of imbecilic, it's just occured to me that it's probably wise to make some provision to prevent any current going back into the port. Probably the simplest and safest way of doing this would be to cut an ADB cable in the middle, and then connect it back up without the +5v line to the Mac end. Instead, divert that line to your PSU. Make sure to label which end is which.

A salvaged PSU from an LC or an external drive box would be a cheap source of regulated +5v. The LC ones are fully shielded - safer. Or you could use an internal drive power splitter and run a +5V and ground line out the back of the 6300. Add a standard DC socket on the back, and plug your ADB thingymabob into that.

Might as well add a +12V/gnd socket while you're mucking about with the drive connector - eliminate another plugpack or two Smile

Warning: ASCII art follows.

Your ASCII art doesn't display. You've probably already figured that out. Tongue

If you're worried about overloading your ADB port, just refrain from connecting useless devices to your ADB port. i.e. a modem that probably very rarely gets used.

My logic:

(a) If you have concerns about overloading your ADB port:
- (i) Disconnect unused devices.
- (ii) Build or purchase switch that allows you to disable unused devices.
- (iii) Build or purchase additional power supply for external devices.
- (iv) Replace ADB powered devices with devices that do not derive their power from ADB port.

(b) If having a pile of additional power supplies laying around is not your optimum solution:
- (i) Eliminate options (a)(iii) and (a)(iv).
- (ii) Investigate options (a)(i) and/or (a)(ii)

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But...

But where's the hack value in that??

/me pictures a little self contained power booster/ADB switch/breakout box

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I found the thread starting t

I found the thread starting to get amusing so I decided I had to make a reply of my own too

I've figured out the adb power problem by looking into the uses and limits of a colorcamera instead Smile

say, on a similar topic: anyone want send me a free original cover panel to fill that gapping hole that the comm slot card used to be on the performa? or do I have to pull out the masking tape? hehe Tongue

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Re: I found the thread starting t

pegasus wrote:

I found the thread starting to get amusing so I decided I had to make a reply of my own too

I've figured out the adb power problem by looking into the uses and limits of a colorcamera instead Smile

say, on a similar topic: anyone want send me a free original cover panel to fill that gapping hole that the comm slot card used to be on the performa? or do I have to pull out the masking tape? hehe Tongue

No offense, Pegasus, but I find your posts to be somewhat confusing. You say that you've figured out your ADB power problem by looking into the uses and limits of a colorcamera instead -- How did you do that?

Correct me if I'm wrong, but you posted this thread because you were concerned about overloading the ADB port on your 6300. How do the uses and limits of a color camera reduce the load on the ADB port of a 6300?

Maybe I'm just misinterpreting your message. Maybe, you're just not concerned about frying your 6300 anymore because a color camera has captured your interest?

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the colorcamera doesn't need

the colorcamera doesn't need the adb port for power at all

I don't mean any harm in saying this but: maybe you should have looked that up before you made that reply above?

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Re: the colorcamera doesn't need

pegasus wrote:

the colorcamera doesn't need the adb port for power at all

I don't mean any harm in saying this but: maybe you should have looked that up before you made that reply above?

I still don't understand how the color camera alleviated your concern about the load on your ADB port. I've reread your posts and have noted that you were concerned with the following devices drawing too much of a load from your ADB port:

- keyboard
- mouse
- tablet
- modem

It's all well and good that your color camera does not use the ADB port to draw power, but this fact does not lessen the burden imposed by the four devices you initially were concerned with. Basically, I don't understand how a fifth device, that does not place a load on the ADB port, will reduce the power requirements of the four devices that you were originally concerned with.

Anyway, maybe it's some type of voodoo thing that's over my head... Tongue

Peace.

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You can add a second supply t

You can add a second supply to the line that will carry the load as long as it's voltage is slightly higher than the ADB port. Since the original source is regulated, you are going to need to use a regulated supply for your booster. They are commonly available and easy to build.

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What happens if the voltage i

What happens if the voltage is slightly lower?

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