[jonnywolfet]

ive had a bit of a search but cant find anything.
my question is this, i have a mint amp that i am currently running from a 12v wall wart, and i want to build a 18v power supply for it (im in the uk, so 240v mains). From what i can gather the tangentsoft tread kit is only for 22v to 36v (that seems wrong, but i cant decipher anything else) there seems to be a world of opportunities out there and its very confusing for someone as noob as me.
so my question is this;

how do i build a low cost, decent quality power supply for my mint?

any help or pointers are appreciated. thanks in advance.

 

[balou]

you need: parts for a tread (or the thread kit) and a transformer. you can grab one at most electronic distributors. toroidal transformers are a bit nicer (less electromagnetic emission).
they convert 240v down to 22v-36v (Ac to AC). you should them buy 3-4v higher than you intend to use in your power supply.
this means: if you want 18v output, you should probably get at least a 21v transformer. you must also look for the maximum current the transformer supports - this should be higher than your intended output current. for your pint, you most likely only need something in the range of 30-90mA, so a transformer capable of 100mA should most likely be enough

oh, and about the voltage: you either could accept the 22v voltage (if your caps and opamps in your pint support this), or you could change one resistor. there's a description on tangents site

 

[beerad]

If you look at the schematic for the TREAD, tangent gives resistor values for setting the output of the TREAD to 12-35V.

 

[kyndig2]

Quote:

Originally Posted by jonnywolfet /img/forum/go_quote.gif ive had a bit of a search but cant find anything. my question is this, i have a mint amp that i am currently running from a 12v wall wart, and i want to build a 18v power supply for it (im in the uk, so 240v mains). From what i can gather the tangentsoft tread kit is only for 22v to 36v (that seems wrong, but i cant decipher anything else) there seems to be a world of opportunities out there and its very confusing for someone as noob as me. so my question is this; how do i build a low cost, decent quality power supply for my mint? any help or pointers are appreciated. thanks in advance.

You just need to get a TREAD (the kit is nice), transformer and then a 1.5K ohm resistor for R2 instead of the standard 2K ohm one. The tread works just fine for 18V, just look at the schematic listed on the TREAD site. Good luck!

 

[jonnywolfet]

fantastic, i knew you guys would come through! thanks very much!

 

[Eokboy]

You can build a TREAD to output voltage as low as the LM317's (or whatever suitable ICs) minimum output, which is like 1.7V(?). Just calculate the resistor values needed from the formula.