Universal Power Pack at 1000 milliamperes.

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Irrawang
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Universal Power Pack at 1000 milliamperes.

Post by Irrawang »

Recently purchased a Universal Power Pack with 1000ma from the local bargain shop (after looking for one for a few years). I've been reassured by folk in the know that a 1000 milliamps will be okay in units having lower amps specified as they will only draw what amps they actually need. My main worry is the Excalibur GM which is supposed to have 100ma only. Over the last few days I've been using the power pack in the GM and all seems fine. Most of my other computers specify around 300ma. The manual for the GM says to only use a power pack with 6-8 volts and 100ma., so I do wonder. I guess I seeking a bit of reassurance that all will be well.

Cheers, Rob.
Always pays to read the manual.
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Murat
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Post by Murat »

If you are getting the correct voltage out of the adapter you are fine.
royb
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Re: Universal Power Pack at 1000 milliamperes.

Post by royb »

Irrawang wrote:Recently purchased a Universal Power Pack with 1000ma from the local bargain shop (after looking for one for a few years). I've been reassured by folk in the know that a 1000 milliamps will be okay in units having lower amps specified as they will only draw what amps they actually need. My main worry is the Excalibur GM which is supposed to have 100ma only. Over the last few days I've been using the power pack in the GM and all seems fine. Most of my other computers specify around 300ma. The manual for the GM says to only use a power pack with 6-8 volts and 100ma., so I do wonder. I guess I seeking a bit of reassurance that all will be well.

Cheers, Rob.
The way it was explained to me is this:

Amps: the device being powered (i.e. the computer in this case) draws as many Amps (or milliamps) as it needs. As long as the power adapter supports that many amps (or more), you are fine. If the power adapter supports less amps than the device wants to draw, that's bad and will result in problems and possibly a fire if done for a long time.

Volts: The power adapter must supply the proper amount of volts as required by the device. The volts are "pushed" to the device and will fry/ruin it if the voltage pushed to the device is too high. If the volts are too low, the device may not function properly.

I'm not an electrician so even this layman's terms description may be incorrect, but it was the way I remember it being explained to me.
Irrawang
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Location: Newcastle, Australia

Post by Irrawang »

Thanks for replies, I've set the pack at 6 volts so all is well. It will be great to be able to fire up my older Fidelity machines such as the CC9 and the Excellence without having to use batteries. I have been warned to make sure to use the correct polarity so no worries their.

Cheers, Rob.
Always pays to read the manual.
JeffB
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Location: Seattle, WA USA

Post by JeffB »

Yes, the current rating in a voltage-regulated power adaptor is the adaptor's capacity, so a machine can draw up to that amount. (Current-regulated adaptors also exist, but they're mainly used in labs to test circuitry.)

It's odd that none of the manufacturers added polarity protection. They had two inexpensive approaches, the cheapest being to add a diode to the power input do that plugging in the wrong polarity stops the machine from working, but without damage. A slightly more-expensive circuit would have made the polarity universal, so that either polarity would work.
Cheers,

Jeff B.
Irrawang
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Location: Newcastle, Australia

Post by Irrawang »

Once when I didn't know what polarity was needed, someone suggested to me to turn the machine on and if it didnt start up then to switch if off quickly. I have only done that once and luckily I guessed correctly.

Cheers Rob.
Always pays to read the manual.
Irrawang
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Posts: 41
Joined: Fri Nov 20, 2015 11:25 am
Location: Newcastle, Australia

Post by Irrawang »

Once when I didn't know what polarity was needed, someone suggested to me to turn the machine on and if it didnt start up then to switch if off quickly. I have only done that once and luckily I guessed correctly. It is good to know that some degree of protection is built in though.

Cheers Rob.
Always pays to read the manual.
JeffB
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Joined: Sat Mar 07, 2015 6:36 pm
Location: Seattle, WA USA

Post by JeffB »

Relying on luck as a degree of protection can be risky. If the machine has no protection, and considering electricity travels at the speed of light (well, sort of), the circuitry could fry long before you turn the switch off. Most machines have polarity indicators near the power input. When in doubt, check online. Nick's site is excellent for that (among many other things), and there are other resources online.
Cheers,

Jeff B.
kosterix
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Post by kosterix »

yeah that sounds like a stupid idea.
Strive for avoiding anything flat that emits light. Love the unhackable chess computer with real pieces and a tactile feel. I do not collect, I live.
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