Different solution for voltage doubling

[Marcvv]

Hi,

There was a post a while back for a different solution for voltage doubling then the usual charge pumps based on lt1054, max1044 etc.
I have searched through the post but do not find it.

I am looking for a voltage doubling for a bbd delay that can give me over the usual 100ma.

Anyone recall the thread?

[DaanJM]

I know of a NE555 (timer chip) voltage doubler:
http://www.circuitstoday.com/voltage-doubler-circuit-using-ne555

I also found this "junkbox voltage doubler" using a few transistors a while ago:
http://www.diystompboxes.com/smfforum/index.php?topic=97141.0

I hope this can help you a bit.

[R.G.]

The charge pump chips can be paralleled for more current.

There are discrete solutions with some kind of oscillator, diodes and transistor switches to do the same thing as the charge pump chips but at higher currents.

However, be aware that even though these circuits don't have inductors, like any switching power supply they pull very short, sharp pulses of current and switch voltages very quickly. These conditions are tailor-made for inducting noise in signal circuits unless you're careful (or lucky!) about layout. The bigger the power switched, the more chance to get interference.

NE555's are notoriously noisy, btw. Use the cmos versions if you use this setup.

[Mark Hammer]

I wouldn't touch a "two clock" circuit (i.e., BBD clock and oscillator-based charge pump) with a 10ft pole.  My layout chops are just not THAT good.

[Scruffie]

I wouldn't touch a "two clock" circuit (i.e., BBD clock and oscillator-based charge pump) with a 10ft pole.  My layout chops are just not THAT good.

I can think of plenty of instances where they've worked without too much hassle, the moosapotamus A/DA has it on board, the Madbean MXR-117 has it on board, I put one on a daughter board under the PCB in my Small clone...clone, lots of people use them with there Madbean Memory Man/DM-2 clones, they actually seem fairly forgiving.

Although now i've said that, i'm sure everyone who did that is going to go home and find there pedal is now miraculously heterodyning 

Speaking of the LT1054 with the Memory Man clones, you say this is for a BBD Delay, sure it wont cover it?

[Marcvv]

Hi all,

Thanks for responding.

I have been working quite a bit with 15 volt bbd delays and each time when I use a charge pump based on the LT 1054 i have a drop in voltage to 14 volt when I use the delay.
The same with every build and with different charge pumps build.
Now I am working on another one and want to be sure my powersupply is reliable at 15 volt so I can experiment with some mods on that delay.
Basically I want a reliable 15 volt powersupply, from 9 volt.
(I know it would be easier to just get a powersupply straight from 18 volt regulated to 15 volt but that is not what my question is about)


RG/Daan: I am aware of your suggestions. Thanks but I am looking for something different.
Mark: untill now I never had any problems with the two clocks interfering in these builds. I know about that possibility.Thanks for reminding me.
Scruffie: I am modding an aquaboy, as you know from Madbeans forum. You suggested already some ideas, thnks for that. But first I want my powersupply to have more current available.

I remember that there was a thread a couple of weeks ago where somebody found a more or less prefab unit with a charge pump that could deliver more current easily.

[duck_arse]

I can never find anything with search.

I think greaser_au sometimes mentions he uses prebuilt step-up modules, but don't quote me on that. maybe you could pm him.

[Rob Strand]

You can of course use a switch mode power supply (smps) ie. a ckt using an an inductor.   Use a shielded inductor, low esr caps and a tight layout. In the old days people worried about noise but these days the switch frequencies are high.
Smps's are used in some portable pro gear these days.

[Morocotopo]

I opened a Fishman Loudbox amp the other day, guess what kind of power supply it has? A switching one. No heavy transformer, weights next to nothing (also because of very very flimsy construction. I almost destroyed it just by opening it).

[Marcvv]

Found it:
http://www.diystompboxes.com/smfforum/index.php?topic=101135.20
http://www.pololu.com/catalog/product/799

Maybe this will work for me.