[mythtv-users] Desk Top Power

[Michael Watson]

On 16/05/2015 8:19 AM, Saul wrote:
> On Sat, 16 May 2015 08:06:18 +1000
> Michael Watson <michael at thewatsonfamily.id.au> wrote:
>
>> On 16/05/2015 7:59 AM, Saul wrote:
>>> On Sat, 16 May 2015 07:44:50 +1000
>>> Michael Watson <michael at thewatsonfamily.id.au> wrote:
>>>
>>> [snip all sophisticated solutions]
>>>
>>> What happened to common sense? If this is an era of smartphones and
>>> whatnot we cannot do simple electrical engineering any more? I was
>>> under 10 when I built my first relay-based automatic switching
>>> system. All you need is a relay driven by PC power supply and you
>>> can switch kilowatts of power on and off with your PC. ;)
>>>
>> Why build it, when you can find them at around the same cost of a
>> suitably rated relay.
>> When you cant buy a device to do what you want (at reasonable
>> prices), then you look at building your own....
> Alright, relay based solution was just an example from dark ages.
> Nowadays I'd use a thyristor to do the same - the cost is around $2
> (not a Radio Shack price).
>
I dont disagree with your logic, but a thyristor is not the only 
component needed.  You will need a plug, a couple of sockets, a suitable 
housing, and of course knowledge and time.  Or you can buy a suitable 
product for under $20.

I would not advocate anybody play around with mains voltage (lethal) 
without the suitable knowledge in what they are doing.

I have built many circuits (and enjoy designing/building) to do what I 
want, when a suitable product cannot be found at a reasonable price.  
ie: Temp controller for my home brew, "12V UPS" for RaspberryPI/Android 
Tablet based media system in the family wagon. If you would rather build 
your own master/slave mains switch than purchase an off the shelf 
product, then that is fine - if you have the suitable knowledge working 
with mains voltages/currents.

Given that the op has asked the question in the first place, to me 
indicates their knowledge of electrical engineering is limited, hence 
the links to suitable off the shelf products.