[mythtv-users] Issues with my HDHomerun: Resource temporarily unavailable

Stephen P. Villano stephen.p.villano at gmail.com
Mon Jan 5 03:43:07 UTC 2015


On 1/4/15 5:51 PM, Mike Perkins wrote:
> On 04/01/15 19:35, Alistair Grant wrote:
>> On Sun, Jan 4, 2015 at 8:24 PM, Ian Evans <dheianevans at gmail.com> wrote:
>>>
>>> Bowing down to those of you with more electrical knowledge, I see
>>> that the
>>> JTA0302B is a 2A power supply while Silicondust says it needs a 1A.
>>> But I do
>>> recall seeing people mention the JTA0302B in the 'dust forums.
>>>
>>> Going back to high school science I seem to remember amps are the
>>> "amount",
>>> while volts are the "presuure" of the power. So what exactly happens
>>> if I
>>> use 2A on something that calls for 1A?
>>
>> The short answer is you'll be OK (but see my assumption below).
>>
>> The important bits are:
>>
>> * The voltage matches (you haven't mentioned them here, I assume
>> they're the same).
>> * The maximum supply current (2A in the example above) exceeds the
>> load requirement (1A in the example above).
>>
>> Just to add to your analogy: I normally think of a tank connected to a
>> hose.  The voltage is equivalent to the height of the tank (the
>> available pressure).  The current is the amount of water that can
>> flow, i.e. the diameter of the hose.
>>
>> However, we can't take the analogy too far - assuming the voltage is
>> correct and everything else is working as it should, the load will
>> only draw as much current as it needs, so over spec'ing the power
>> supply won't hurt.
>>
> Perhaps, but see my earlier note in this thread. A larger power supply
> may need to draw a certain minimum current before it will regulate
> properly, or at all.
>
> 2A supply serving a 1A load should be OK, I do that all the time.
>
Good note. One I also mentioned above.
An one amp load being delivered by a two amp supply, not a biggie. One
could even envision a five amp supply delivering to a one amp load, it's
within the realm of common practice. A one hundred amp supply attempting
to supply a one amp load, some supplies might actually do so, most would
give an underload (or overload) condition report and not deliver.
Some, far earlier supplies either shut down without an error (as
reporting wasn't considered in those days) or blew sky high.


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