12V 3A household transformer for EM11?

[taxman (Matt)]

I am fairly sure this was already asked and replied to, but I can't find the thread, so I hope no one will be too annoyed if I ask again.

I have a powertank that I think has had it - last night I got about 90 minutes running my Atik 314 and EM-11 before the dreaded amber light came on.

I have an old computer transformer with a 12V 3A output and was wondering whether this would be suitable for the mount which requires 12V between 0.8A and 1.3A (the manual is a little unclear).

I can never remember whether it was the voltage or the amperage that "pushed" or was passive.

Prolly an easy reply for someone in the know, but I have filled myself with rage this morning driving back and forth between home and Jaycar trying to get a serial-usb connector THAT ACTUALLY WORKS.

[acropolite (Phil)]

In a nutshell the current rating is irrelevant, the devices you have will draw their correct operating current at the nominated voltage, make the voltage higher and they may or may not draw more current dependant on the design of the device, there's really no single rule you can apply.

Many cheap 12 volt sources are unregulated, that can be a problem as the nominal 12 Volts is often around 18 and only drops when full load is used.

Provided yor Plugpack is regulated and around 12 Volts and DC you should have no problems, the current rating can be anything equal to, or greater than the current you need to run your devices.

Make 100% sure that the polarity of the connecting plug is correct, reversing the connection can have nasty consequences.

[taxman (Matt)]

Thanks Phil - I couldn't remember which was which.

[RickS (Rick)]

Originally Posted by acropolite

Provided yor Plugpack is regulated and around 12 Volts and DC you should have no problems, the current rating can be anything equal to, or greater than the current you need to run your devices.

I'd go for greater rather than equal to. 30% or more would be good (3A is heaps for a max 1.8A draw.) I have some experience with mass produced plug pack and switch mode power supplies and they don't build in any more quality than absolutely necessary.