OK, this isn't actually PC related but seemed like the most fitting forum...
I just got myself a SpeakerCraft SL-One speaker A-B switch for sharing my pair of front speakers between my AV and stereo amps. The switch arrived today but doesn't include a power supply!
The requirements are 12V (2.1mm) and 120mA so I thought fine, I'll just get an adjustable one from Argos or Maplin. However, it seems that while voltage adjustment is common I can't see anything about current adjustment and 120mA seems very uncommon. Then I started reading about regulated adapters to control current then polarity was mentioned and now I'm completely confused!
Please help!
Advice about AC/DC power adapter required
Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee, Devonavar
Hi
A power supply will supply only the power required to power the device. P=IV and the voltage is fixed (in this case at 12 V), so to vary the power we must change the current, which may be anything from around 0 A to potentially above the maximum current specified by the power supply.
With this in mind you can now buy almost any 12 V DC power supply available to you and have to work.
Maplin for example have:
http://www.maplin.co.uk/Module.aspx?ModuleNo=19160
http://www.maplin.co.uk/Module.aspx?ModuleNo=13453
Note one is regulated and the other isn't, the advice that I've been given is that since its a speaker buy a regulated power supply if the speaker is unregulated, or buy a unregulated power supply if the speaker is regulated, if your unsure buy a regulated one.
A power supply will supply only the power required to power the device. P=IV and the voltage is fixed (in this case at 12 V), so to vary the power we must change the current, which may be anything from around 0 A to potentially above the maximum current specified by the power supply.
With this in mind you can now buy almost any 12 V DC power supply available to you and have to work.
Maplin for example have:
http://www.maplin.co.uk/Module.aspx?ModuleNo=19160
http://www.maplin.co.uk/Module.aspx?ModuleNo=13453
Note one is regulated and the other isn't, the advice that I've been given is that since its a speaker buy a regulated power supply if the speaker is unregulated, or buy a unregulated power supply if the speaker is regulated, if your unsure buy a regulated one.