pedal power in 125B schematics/parts ideas?

[kodiakklub]

anyone ever tried jamming a DIY power supply in a 125B before? suggestions for transformers and other parts? i plan on designing/etching a pcb for it. happy to share the layout/results im familiar with the basic structure of the circuit, but wondering if anyone has worked it into a super small space. regulated at a minimum. thanks!

[Mark Hammer]

The difficulty would depend on the amount of current, and variety of output voltages you plan to supply.  If you want to provide a couple of amps, and have individual outputs providing up to an amp, you'd need space for a bigger transformer, and space for the larger heat-sink-equipped regulators, unless you opted for a switching type.

I do think, however, there is a need/desire for a "po' boy power brick".  So, something inexpensive that could provide a nicely regulated 12V, a couple of 9vdc outputs, each of which could be daisy chained, and a status LED to let you know the power is on.  One output could have a "starve" control, if you wanted.  The unit does not HAVE to include the transformer.  Consider the possibilities of simply having a jack for an AC wallwart that provides, say, 12VAC to the box, and what's in the box turns that into something more useful.

I like to make "power distribution boxes"; little plastic boxes that take a moderately regulated 9VDC input, pack on some more smoothing capacitance and a status LED, and provide a bunch of paralleled outputs that can then be run to individual pedals, or daisy-chain cables.  But these are passive, and don't provide the variety of output configrations that modern players need.  No great sin in aiming for a step up from that.

[kodiakklub]

yes a po mans power brick is exactly what im looking to do. only 9vdc+ outputs. outboard AC transformer in a wall wart is genius. i want as many DC outputs as will fit. no starve function. an LED for AC and maybe DC indication. a DC fuse if i do an external AC tranny? switching type regulator or power supply?

If you want to provide a couple of amps, and have individual outputs providing up to an amp, you'd need space for a bigger transformer, and space for the larger heat-sink-equipped regulators, unless you opted for a switching type.

[Mark Hammer]

I include the LED on the post-regulation DC path, just to let me know if the wallwart is still plugged in or not.

And while it is not a requirement, personally, I like to use the plastic boxes, just to have a chassis that is absolutely neutral when I touch it.  It also reduces pedalboard weight.

Finally, it is no crime to include a "power-thru" jack for extending to another box.  So, imagine you have a 12VAC wallwart.  You plug it into power brick A on one corner of the pedalboard.  That unit provides a handful of smooth, isolated, well-regulated 9VDC outputs.  Even though unit A can function on its own, one of the jacks (perhaps on the end opposite to where you plug in the wallwart) provides power-thru for the 12VAC, which lets you run a cable to a second box, power brick B, where perhaps you turn that 12VAC into 15VDC, 12VDC, or +/-9VDC, or +/-12VDC, or whatever, for "special" pedals.  And there is no reason why that can't have a power-thru jack as well, just to let you swap where you situate A and B on your pedalboard, with perhaps the unit your wallwart goes into always in the upper left-hand or upper right-hand corner, depending on yur pedalboard setup or wherever the most convenient connection to an AC outlet for the wallwart is situated.