Re: [Electronics_101] Re: Building a Quad/Octo/Dozen USB 1amp charger
- On Sun, Jan 1, 2012 at 4:51 PM, Stefan Trethan <stefan_trethan@...>wrote:
> **Yeah you have the brains for sure. Me I will be working off templates other
> I would not want to be the engineer who has to actually make this.
> Wait... I am the engineer who would actually have to design this, damn!
smart people design with small tweaks standing on shoulders of giants and
>Well once we made the MegaDC power box i.e. say 36v and we standardized it
> It is tricky enough to get a power supply to make a narrow range of
> voltages and currents while fulfilling all the requirements (such as
> LOW COST, efficiency, LOW COST, standby power consumption, LOW COST,
> safety, LOW COST, emc, LOW COST, oh, and CHEAP!).
and standardized the smart plug where all DC devices (from phone to laptop
to tablet to powered speakers, etc.) then cheap comes. Cheap comes when you
can manufacture millions and billions not thousands. Standardization helps
achieve cheapness. Look at how cheap PCs and Laptops became compared to 2
decades ago and Flat Monitors and Printers. WinTel standardization helped
because high volume sales leads to cheap manufacturing and of course
manufacturing by robots (and people in very poor countries with low wages,
unsafe conditions, and anti-environmental policies/non policies is the ugly
side of cheap hardware).
> Making several voltages "on demand" is not a reasonable idea. WhatWhy are smart plugs such a bad idea they could make the request for n volts
> could work is using a relatively high voltage, say 48V like used for
> power over ethernet (yet another grand idea abusing data connectors).
> It could be transmitted over short distances using reasonably thin
> wires, with DC/DC converters on the device end.
at say n amps and the BIG DC BOX at panel box could send what they need.
Such a smart power supply capable of putting out dozens of different volts
and currents would need a very good design but could get cheap when the
power companies, best buy, Walmart offered them to just plug into a wall or
breaker panel. And then we would have one bulky smart power supply under a
table, in the basement and no dozens of transformers around the house. No
need to use Ethernet one could make a new "end' for some Romex style cable
could be called DCRomex*
They say all progress is made by unreasonable men a Smart DC box that
supplied various power to various devices with not transformers at the
device level would be hailed by consumers as the be all end all. install
one oversized smart DC power box and eliminate dozens of transformers and
trips to store to replace broken or missing ones. One DC smart power supply
and plugs to rule them all. My QuadFast charger would just use a smart plug
and ask for 5v 24amp (2 amps per each plug) max and the DC box would
* AC Romex should have had standardized ends rather than forcing splices
years ago from my viewpoint. Some kind of ends that the 2 wires could not
be plugged in wrong to outlets and fans, etc. Think the kind of clever
idiot proof connectors that could not be put on the wrong side ever. A lot
of electricians would not be charging people a lot to put in a new outlet
if such romex ends existed and outlets and ceiling fans were installable
safely by laymen without having to read manuals instead they could focus on
reading Electrical codes and inspectors would be getting a ton more
business and electricians would focus on inspecting whether something was
to code rather than charging to put in ceiling fans, smoke detectors,
additional convenience outlets, etc.
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- I wrote:
>> Smart devices use transistors (or other circuits) to keep thejong kung <jongkung01@...> writes:
>> high-current parts of the circuit disconnected until the power
>> requirements are negotiated.
> Didn't ST post that if the middle two connectors (data wires) areAny device that looks for that, has "negotiated" for the power, and is a
> shorted, the USB power is known basically a dumb charger and no
> negotiations will happen ?
smart device in my book. In theory, if it doesn't see the short, it
should choose not to draw as much power since it doesn't know that the
thing it's plugged in to is a "dumb charger".