I'm looking at this amp:
http://s.aliexpress.com/zY3miYNj
It states it requires:
– Supply voltage: double DC power supply +- 58~ +- 70V.
- Rated output power: 500W (+- 65V power supply.
Any ideas?
Electrical – a “double DC power supply”
amplifierdcdc/dc converterpower supplyswitch-mode-power-supply
Related Solutions
A capacitor input power supply is only appropriate for specific, low current, non-isolated applications, like tickling a SMPS into life, or driving an isolated low power LED bulb, where safety is not an issue, and a constant output current is OK.
As you want to drive microcontrollers and actuators, safety and isolation is paramount, and this is the wrong design to use. In addition, 1A is quite high, and the load will vary, so this type of supply is triply inappropriate.
If an iron transformer based supply is too large for your application, see if you can find a complete SMPS solution, like a USB charger. If they are too big, then you need to rethink your project dimensions.
When you do your own designs, it's often quite easy to get the behaviour you intend, say 1A output. It's more difficult to avoid the behaviour you don't intend, like electrocuting yourself. That's the reason that people buy isolated power supplies rather than build their own, anticipating all the bad things that can happen, then avoiding them, takes a lot of experience. You're unlikely to get it right and safe first time.
This Class 2 is the symbol for Double Insulation with no earth wire.
Referenced in :
IEC 60065
IEC 60950-1
IEC 62368-1
Best Answer
From the specification:
Working backwards from the rated output:
We need to calculate with RMS to work out the peak to peak voltage which will be given by \$ V_{P-P} = 2 \sqrt 2 V_{RMS} = 2 \sqrt 2 44 = 124 \; V_{P-P}\$
To generate this we would need a supply voltage of +/- 62 V plus a few extra for headroom. Given that the spec indicates 70 V max., you don't have a lot of room to manoeuvre.
All this assumes that one speaker terminal is connected to the supply common. If, as would be more common, the amplifier drives the speaker in bridge mode then a single-ended supply could be used and polarity reversal done by the H-bridge. In this case neither speaker terminal is grounded.