Planning my Harbinger One build

[bcalla]

I have been reading about the power options, and have a question.

My board power supply has an 18v output which I don't use, so I can power it with 18v on my board.  But when I go over my friend's house to jam I don't always bring my board - sometimes I will throw a couple pedals & 9v power supplies in a backpack.

Has anyone considered setting it up to handle both 9v & 18v?  Maybe use a center-off toggle switch to kill power altogether and save the wear & tear on the bulb?

Thanks,
Bob

[jubal81]

Pretty cool idea. Might want to add some protection in case it's flipped to 9V when plugged in to 18v. Reverse biased Zener might do the trick.

[Rockhorst]

I'm at the same point hehe. The easiest solution is to build an external voltage doubler in a small enclosure I guess. When you jam without thebigboard, just hook it up to that external box for 18V. I do like. The idea of a dedicated on/off switch, though switching bulbs on/off also causes wear.

[bcalla]

I like the idea of power protection, that makes a lot of sense.

I didn't see myself toggling the power off & on very much.  Depending on how I use it I could see picking the source voltage and leaving it on for the night, or if I only wind up using it for 1 or 2 songs just power it on when I need it.

I haven't purchased the components yet, so I haven't seen the bulb.  I was also considering whether I should socket it to make it easy to replace if needed.

[bcalla]

I don't have much any experience designing circuits, so I spent some time googling Zener diodes.  I understand the basic concept, and threw a 1k resistor + a 9.1v Zener on a breadboard to see how it works.  I was able to keep the voltage down to 9.5v with an 18v source, but I'm not sure about the current.  From the build doc it appears that you need at least 100mA for the Harbinger One.  Since the Zener circuit needs a current limiting resistor, is this even possible?  If so, what resistor value  would work?

Thanks,
Bob