Charge Pump

[modsquad]

I was doing some research into Charge Pumps and ICs used.  One thing I noticed is that most of the circuits provide low current values.  I know you could probably replace a resistor here and there but they still wouldn't put out much.  Is that an issue for effects you want to run at 18v+, or does it depend on the type of effect as far as current draw?

[R.G.]

It depends on the effect. If the effect pulls less than the current the pump puts out, all is well. If the effect needs more than the pump can do, you need to supply more current. You can supply more current by using parallel charge pumps or some other power supply technique.

[petemoore]

  Exceed the current rating of components at your own risk, likely it'll fry if exceeded by 10%...
 Every circuit has a different current requirement. I use MAX1044's to get ~17v from 9v, this works fine for my booster and octave, the only two things I really want to run on a '~2x' voltage.
 Charge pumps are somewhat limited in current capability, I would build a power supply if I needed bigger current flow @ voltage.
 

[modsquad]

That's what I was kind of wondering.  I was thinking for boosters, ruby type amps, etc.  to get more headroom whether a charge pump would put out enough current to make it feasible using 9v DC as power source.

[Sir H C]

If you need more current you can look at inductor based boosters.  These can handle a lot more current because they often have to have only one switching device versus 4 for the charge pumps.

[grapefruit]

For a booster amp using one or two Mosfets or transistors, or a not so power hungry op amp the MAX1044 would generally be fine. Not for powering an LM386 or a bunch of op amps though.

I've not had a lot of joy with some of the switchmode inductor based devices. Apart from having ripple on the output, which can be gotten rid of, they also put a lot of noise and ripple on the input, which is not good if you are powering 9V devices daisy chained from the same 9V source.

Stew.