Re: Voltage Converter?

w_tom wrote:
On Mar 30, 2:19 am, da...@xxxxxxxxx (Dave Martindale) wrote:
You're actually talking about two different power supply designs.

Many desk/tower computers have a power supply with a 120/240 V switch on
them. The switch changes the configuration of the input circuitry to
either be a normal full-wave rectifier (when set to 240) or a voltage
doubler (when set to 120). When set correctly for the voltage applied,
the input capacitors have about 300 V across them and this powers the
rest of the power supply. It's basically a circuit designed for a
single supply voltage, with a switchable voltage doubler in the input.

I discussed many power supplies that meet a criteria called
"universal power supply". Also discussed is another type that does
multiple voltages by manually switching a 110/220 switch. Some
manufacturers would take out that power switch, replace that switch
with an IC, and create a "universal power supply". It could be that
simple.

No, laptops supplies need not use that 'switch replacement' IC
because that supply can be designed from scratch. However even 20
years ago, power supplies with a 110/220 switch were also manufactured
with an automatic switch - that IC - so that it switches automatically
on 120 volts or 240 volts without human action. "Universal power
supplies" were even common in some video monitors 20+ years ago. IC
to replace that switch was only one way to create a "universal supply"
20+ years ago. The point - universal supplies have existed for
decades.

If a portable appliance does not implement a "universal power
supply", then what else was forgetten? Universal supply should be
standard in any portable appliance.

What power plug for that country? See:
http://www.interpower.com/ic/guide.htm

One point has not been mentioned in this interesting discussion: it looks like everybody think it is normal to have outside bricks instead of integrated power supplies. Although this is understandable for laptops (I seem to remember one manufacturer attempted at some point to integrate the power supply into its laptops; cannot remember which) because of space and heat considerations, how come we accept to deal with multiple external power supplies? It is a waste of energy since unless you unplug them, they are always on, of space (difficult to make them coexist on a power rack) and after a while, it becomes difficult to tell which one works with which appliance.

One more example where manufacturers have it their way and customers just assume that is the way it should be. Fight back !

--
John Doue
.

Relevant Pages

  • Re: Power supplies keep crapping out on me
    ... It might jist be the off/on switch just went bad. ... I've now had three power supplies fail on me. ... The most recent failure was sometime last week. ...
    (comp.sys.apple2)
  • Re: Bridgeport boss 4 Spindle not powering up (continued)
    ... you need to reset a safety interlock on the motor switch pod ... I can work my way through the average power ... activate the spindle all he would get would be a buzzing sound. ... each for a different axis stepper motor drive). ...
    (rec.crafts.metalworking)
  • Re: PC doesnt start
    ... With the switch pressed the voltage are within the specs but, ... I measured the voltage at the Power switch plug, when connected to the MoBo, ... Why then would a power switch or connections be ...
    (microsoft.public.windowsxp.hardware)
  • Re: Protecting the system
    ... Two notices, one "press briefly to shut down" pointing at the power button, ... the plug or, if it has a switch, the PSU. ... minimise writes to the flash device which ext3 would be constantly doing ... The other thing I need to store is the system configuration files - ...
    (uk.comp.os.linux)
  • Re: second power supply
    ... How often do you reach to the back of the computer and switch the main PSU switch off? ... there is always power to the ... The link I provided was to show the workings and wiring of the PS-ON mechanism on a PSU and to counter your argument that more needed to be done than closing the circuit in question to get the PSU to work. ...
    (microsoft.public.windowsxp.general)