Electronics > Beginners

Best choice oscillator for low powerdraw, low component count, ca 1-5kHz

(1/4) > >>

ALonda:
Im a self-taught beginner level hobbyist trying to design some basic voltage doubler/booster circuits for other various projects.

My current choice of doubler is a boost circuit that requires an input from an oscillator to function. While I know how to make simple 555 and inverter oscillators, and have schematics for opamp oscillators, I dont know how to make RC oscillators or anything else.

As I am a bit of a perfectionist and minimalist, naturally im always looking to minimize component count and power consumption, as well as trying to make it as efficient as possible.

Ofcourse I could probably just order some cheap complete IC, but then I wouldnt learn anything so whats the point of that?

So I would like to put the question to all you knowledgable guys n gals, if you could maybe help me rank different kinds of oscillators in terms of component count (simplicity) and power consumption?

Also, is squarewave or sine better for a coil based booster? for a diode/transistor based doubler?

Ive heard something about a crystal based oscillator only drawing microamps, but the output would be in the 30kHz range, which I dont think would work with the 1mH coils I have for my voltage booster (my target voltage is 5V from about 3.5-4V, as well as 14V (only ~2uA) from 5V).

Kleinstein:
For best efficiency one wants to switch the main current hard, so more like a square wave. The voltage can actually be more sine like in a resonant circuit.

There a several types of low power oscillator:
Lowest part count would be a small µC running of internal RC clock - this could be a few µA.
There are charge pump chips (e.g. ICL7660 like) that provide there own clock - but again kind of overkill.
From the NE555 there are similar CMOS versions (e.g. LMC555) with lower power than the old NE555, but usually still not very low power.
There is RC type with a low power comparator (e.g. MCP6541 or similar with supply current below 1 µA).
However on has to be careful with supply current specs - the current can go up, it the comparator / Schmidt trigger is close to switching.
This is a catch when considering a HC1G14 schmidt-trigger as an oscillator.

bd139:
LTC6906. Much win that IC. 12uA. One resistor. Done!

Although you'd be better looking at the canned ICs that do this.

Benta:
Depends on how precise the frequency needs to be. If it's uncritical, a simple RC oscillator using a single-gate Schmitt trigger inverter is the simplest.
For better precision, an oscillator using a 32,768 kHz crystal plus divider is better.

Both can be built with consumption in the uA range.

You'll need to be a bit more specific.

ALonda:
bd139, its always disheartening to see replies like yours, especially since I specifically put


--- Quote ---Ofcourse I could probably just order some cheap complete IC, but then I wouldnt learn anything so whats the point of that?
--- End quote ---

in my original post. I mean, whats the point of learning, eh? And you even mention a 10kHz+ IC when the topic says 1-5kHz.

Great job.

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod