Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Over Voltage / Amperage DC power converter

I have a non mission critical device (a "Super Bark Free" ultra sonic
dog anti-bark trainer) that as an alternative to battery power calls for a
200mA 6V DC power converter.

I am wondering if I might get away with a higher powered converter. For
instance, I have an old PC speaker wall wart DC converter that is 300mA at
9 volts.

Will most low power devices like this tolerate a 50% over volt and over
amp, or would it likely result in a quick failure of the device?

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Default Over Voltage / Amperage DC power converter


"Tony Sivori" wrote in message
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I have a non mission critical device (a "Super Bark Free" ultra sonic
dog anti-bark trainer) that as an alternative to battery power calls for a
200mA 6V DC power converter.

I am wondering if I might get away with a higher powered converter. For
instance, I have an old PC speaker wall wart DC converter that is 300mA at
9 volts.

Will most low power devices like this tolerate a 50% over volt and over
amp, or would it likely result in a quick failure of the device?

--
Tony Sivori
Due to spam, I'm filtering all Google Groups posters.


The current rating of the power supply is unimportant - sort of - as long as
it is at least enough. I say "sort of", because it depends on whether or not
the supply is regulated. If it is, then it doesn't matter how little, or how
much, up to the rated current level, that you draw from it. The voltage will
remain at 9v give or take. If the supply is unregulated, then the chances
are that it will be rated at 9v nominal, only when it's loaded close to its
maximum. At lower currents, the voltage could well be 20% above that,
particularly with small transformers which are notorious for poor load
regulation. So the output could easily be up around 11v when lightly loaded.

Your bark trainer might well tolerate this, even though it represents
getting on for 100% over-voltage, but it is a risk that I don't think I
would want to take for the sake of shelling out the small amount that a
suitable 6v regulated wall wart would cost.

Arfa


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Default Over Voltage / Amperage DC power converter

On Sat, 09 May 2009 16:08:51 +0100, Arfa Daily wrote:

The current rating of the power supply is unimportant - sort of - as
long as it is at least enough. I say "sort of", because it depends on
whether or not the supply is regulated. If it is, then it doesn't matter
how little, or how much, up to the rated current level, that you draw
from it. The voltage will remain at 9v give or take. If the supply is
unregulated, then the chances are that it will be rated at 9v nominal,
only when it's loaded close to its maximum. At lower currents, the
voltage could well be 20% above that, particularly with small
transformers which are notorious for poor load regulation. So the output
could easily be up around 11v when lightly loaded.

Your bark trainer might well tolerate this, even though it represents
getting on for 100% over-voltage, but it is a risk that I don't think I
would want to take for the sake of shelling out the small amount that a
suitable 6v regulated wall wart would cost.


Thanks for that. Sometimes I am too cheap for my own good.


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Default Over Voltage / Amperage DC power converter

On May 9, 10:40*am, Tony Sivori wrote:
On Sat, 09 May 2009 16:08:51 +0100, Arfa Daily wrote:

The current rating of the power supply is unimportant - sort of - as
long as it is at least enough. I say "sort of", because it depends on
whether or not the supply is regulated. If it is, then it doesn't matter
how little, or how much, up to the rated current level, that you draw
from it. The voltage will remain at 9v give or take. If the supply is
unregulated, then the chances are that it will be rated at 9v nominal,
only when it's loaded close to its maximum. At lower currents, the
voltage could well be 20% above that, particularly with small
transformers which are notorious for poor load regulation. So the output
could easily be up around 11v when lightly loaded.


Your bark trainer might well tolerate this, even though it represents
getting on for 100% over-voltage, but it is a risk that I don't think I
would want to take for the sake of shelling out the small amount that a
suitable 6v regulated wall wart would cost.


Thanks for that. Sometimes I am too cheap for my own good.

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Tony Sivori
Due to spam, I'm filtering all Google Groups posters.- Hide quoted text -

- Show quoted text -


Any 6 or maybe 7.5 V max supply that is capable of providing at least
200 ma should work, assuming the connector is correct. Most supplies
have the center conductor as +, but not all so be sure to check.
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Default Over Voltage / Amperage DC power converter

Tony Sivori wrote:
On Sat, 09 May 2009 16:08:51 +0100, Arfa Daily wrote:

The current rating of the power supply is unimportant - sort of - as
long as it is at least enough. I say "sort of", because it depends on
whether or not the supply is regulated. If it is, then it doesn't
matter how little, or how much, up to the rated current level, that
you draw from it. The voltage will remain at 9v give or take. If the
supply is unregulated, then the chances are that it will be rated at
9v nominal, only when it's loaded close to its maximum. At lower
currents, the voltage could well be 20% above that, particularly
with small transformers which are notorious for poor load
regulation. So the output could easily be up around 11v when lightly
loaded.

Your bark trainer might well tolerate this, even though it represents
getting on for 100% over-voltage, but it is a risk that I don't
think I would want to take for the sake of shelling out the small
amount that a suitable 6v regulated wall wart would cost.


Thanks for that. Sometimes I am too cheap for my own good.


I have good luck finding wall-warts at certain thrift shops, FWIW.




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Default Over Voltage / Amperage DC power converter

I have good luck finding wall-warts at certain thrift shops, FWIW.

Good suggestion. One should take along a multimeter to check their polarity
and no-load voltage.


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Default Over Voltage / Amperage DC power converter


William Sommerwerck wrote:

I have good luck finding wall-warts at certain thrift shops, FWIW.


Good suggestion. One should take along a multimeter to check their polarity
and no-load voltage.



Or just take the whole box home when they are giving them away.


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