Lower voltage power supply

sevenhills

Following on from the post about fuses, what are the advantages and disadvantages of lower voltage devices?

I have just bought a new Samsung monitor and it has a lower voltage. Do they use power just by being plugged in and ready, but the monitor switched off?

Laptops also have these lower voltage plugs.

TadleyBaggie

Define lower voltage.

To supply x watts of power, if the voltage is lower than the current required will be higher.

Section62

sevenhills said:

Following on from the post about fuses, what are the advantages and disadvantages of lower voltage devices?

I have just bought a new Samsung monitor and it has a lower voltage. Do they use power just by being plugged in and ready, but the monitor switched off?

Laptops also have these lower voltage plugs.

It depends on the design of the device.  Most will consume at least a small amount of power even when the appliance (e.g. the monitor) is switched off.

Some may be marked with a 'Standby' (or sometimes 'Quiescent') consumption, but I wouldn't rely on that too much.

The only way to know for sure is to buy a plug-in energy meter and check each one.

The advantage for the manufacturer is a reduction in costs in that the appliance can be designed for safety for the low voltage (rather than 'mains' voltage), and rather than designing and making different appliances for each market, they can just ship different power adaptors depending where the appliance is being sold, or with variable input voltage adaptors all they need to do is provide a lead suitable for the local plug/socket system.

grumbler

sevenhills said:

Following on from the post about fuses, what are the advantages and disadvantages of lower voltage devices?

I have just bought a new Samsung monitor and it has a lower voltage. 

Lower voltage means an external power supply. I hate such devices. There are two reasons:

• Manufacturers are lazy. It's easier for them to make the same devices for all all regions with different mains voltage. Then they  just enclose different exteranl PCUs.
• Manufacturers are driven by our spoiled taste - most people like 'slim' monitors and don't care about the mess caused by cables and external PSUs.

 they use power just by being plugged in and ready, but the monitor switched off?   Laptops also have these lower voltage plugs.

Most modernt PSUs draw almost no power when there is no demand (the monitor is switched off)

Laptops are portable devices and have to be slim and not heavy. In this case it does make sense to have a separate PSU and don't carry it when you don't need it.