Hello everyone, this is my first post on this forum. Looks to be a great forum that I can add to my list!
For almost a year now I have been working on a multi guitar FX pedalboard similar to those built by Pete Cornish for David Gilmour of Pink Floyd.
The board is comprised of a wooden enclosure housing around a dozen FX units. All but 3 are powered by 9vDC, most of which only pull about 5-20ma.
Two of them are AC powered tube units, requiring 24vct'd ac and 12vac both at 200ma. The third is about 50ma at 15vac with an onboard regulator.
I have a custom built tranformer arriving which has about 14 secondaries. (AC120 primaries). Except for those 3 FX units that require AC input, each secondary is rated at 12v 100ma (two are 200ma)
I want to build a VERY VERY clean noise free highly regulated power supply for each individual secondary and therefore each FX board gets its own independent power to reduce ground loops etc.
I am new to power supply design, but understand the basics. I want to to be VERY clean but I do not want to use something as complex as the Super Regulated supply i found on this board earlier. I saw in pictures that Pete Cornish uses extremely large (at least 10,000uf) filter caps directly after the bridge rectifier so I plan on doing this if possible with my transformer specs.
My questions are: with the 7809, and the 12vac power supply at 100ma (remember only about 20ma needed) How large can/should I go with the Filter cap and then what other features should I include to make it a very good power supply? I will post pictures of my board and an idea for a schematic I have so far.
Thank you! Sorry for the lengthy post!!
For almost a year now I have been working on a multi guitar FX pedalboard similar to those built by Pete Cornish for David Gilmour of Pink Floyd.
The board is comprised of a wooden enclosure housing around a dozen FX units. All but 3 are powered by 9vDC, most of which only pull about 5-20ma.
Two of them are AC powered tube units, requiring 24vct'd ac and 12vac both at 200ma. The third is about 50ma at 15vac with an onboard regulator.
I have a custom built tranformer arriving which has about 14 secondaries. (AC120 primaries). Except for those 3 FX units that require AC input, each secondary is rated at 12v 100ma (two are 200ma)
I want to build a VERY VERY clean noise free highly regulated power supply for each individual secondary and therefore each FX board gets its own independent power to reduce ground loops etc.
I am new to power supply design, but understand the basics. I want to to be VERY clean but I do not want to use something as complex as the Super Regulated supply i found on this board earlier. I saw in pictures that Pete Cornish uses extremely large (at least 10,000uf) filter caps directly after the bridge rectifier so I plan on doing this if possible with my transformer specs.
My questions are: with the 7809, and the 12vac power supply at 100ma (remember only about 20ma needed) How large can/should I go with the Filter cap and then what other features should I include to make it a very good power supply? I will post pictures of my board and an idea for a schematic I have so far.
Thank you! Sorry for the lengthy post!!
If u need clean power supply, then 7809 will not do.
At least u have to go for LM337 and the likes.
It is easy to get clean power from batteries. The 9V alkalines are good, but if u don't want the hassle of replacing them, then install NiMHs and a charger. Also wire a ON/OFF switch for the charger.
Gajanan Phadte
At least u have to go for LM337 and the likes.
It is easy to get clean power from batteries. The 9V alkalines are good, but if u don't want the hassle of replacing them, then install NiMHs and a charger. Also wire a ON/OFF switch for the charger.
Gajanan Phadte
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