Hello, i'm designing a compact 9V power supply for musicians. I wanted to check a couple of things with you before it goes "smoke" on the water.
It should accept AC voltages from all over the world and output a few(4-8) 9V 250mA DC channels.
My basic idea is:
1.input fuses and little filtering
2.90-264V to 12V switching transformer
3.big 12v 105°C cap
4.one or more linear regulators to 9V
5.final small 9V caps per channel
(ok the hybrid regulating thing has already been done,but i didn't knew it!See?I have a couple of good neurons, if you teach me
)
A thing to keep in mind is that many instruments/pedals are very poorly designed(even for my knowledge) so you must expect them to have a poor to non-existent power supply section, expect ground loops and noise pickup even from Saturn rings' static.
From experience, a pedal A can interfere with pedal B attached to the same supply line, and vice versa.
My first tought was to use a single linear regulator per channel, but they consume a lot of space,money and heat.
Would a single 9V linear regulator followed by an LC filter per channel do the job? We're not interested in high frequency noise, mainly in mains hum and audible frequencies.
Heavy discounts for anyone who helps