How can this be done?
30v sinusoidal or square?
unipolar or bipolar?
If sinusoidal is that rms or peak voltage?
Frequency resolution?
Come to that why not say what you are trying to do so we can avoid xyproblem.
I need square wave.I know that when I plug my multimeter it needs to say 30V AC.I think 30v should be peak voltage.Not sure should it be unipolar or bipolar.I need to make bee venom collector and it's made by putting 30v AC 0.22A and about 400Hz trough metal mesh and bees are being shocked and it makes them angry so they sting at glass plate,but it shouldn't kill them.
http://www.buykorea.org/images/files_new/mp/gd/2013/05/05/20130505060705792_018_RE.jpg
Multimeters usually measure fake rms, so reading 30V for a square wave means 84V peak-to-peak.
(The meter assumes sine wave but only measures peak and converts).
Some multimeters are true-rms (and they usually boast about it if so), so 30V would then mean
a 60V peak-to-peak square wave.
0.22A will stop a human heart, its certainly going to kill a bee (in fact boil it). From my googling
I think you only need a few mA - battery operated bee veno collectors run for months from one
set of AA batteries, for instance.
So a small H-bridge running at several 10's of kHz driving a small step-up transformer with a 1:10
ratio or so might be the simplest way - assuming you're happy designing small ferrite core transformers.
would a 555 timer be better solution? my plan is to make one control box and 50 collectors running of that one box.Well I might actually include bluetooth.Also I can't seem to find transformers on ebay that would be good for my needs.I saw several people mentioning that unit has 0.22A and it doesn't sound too much @30V DC but not sure how it goes with AC.Check their current ratings: http://www.beevenom.com/collectordevices.htm
30v at 0.22A is aout 6 watts - I'm not surprised a bee gets angry if not dead.....
My copious array of databooks doesn't seem to detail the conductivity or themal mass of bees.
Why not buy a cheapo audio amplifier, and drive it with a 555 - or the tone() function of an arduino? A few ohms in series with the output would make it safe against shorts ( fried bees) .
Sadly my databooks don't cover fried bees either.
Allan
I agree with you but it would be 6,6W on dead short.
But as far as I know dry skin has resistance of max 100000 Ohms, let's say it is 50k for bees,and 50k doesnt sound like it could get bee fried.I think I can even put my tongue on it.Sorry if I'm wrong,this is my first time with AC.Also nice idea with audio amplifiers,I have 20 of pam8403 (ordered by mistake) so I can give them a try.How do I wire that thing to arduino? It has left,right and gnd for input,so I connect gnd to gnd of arduino and L and R to a digital pin? but if it's not complicated I might even use 555 timer
Nikola19992:
would a 555 timer be better solution? my plan is to make one control box and 50 collectors running of that one box.Well I might actually include bluetooth.Also I can't seem to find transformers on ebay that would be good for my needs.I saw several people mentioning that unit has 0.22A and it doesn't sound too much @30V DC but not sure how it goes with AC.Check their current ratings: http://www.beevenom.com/collectordevices.htm
Yes I nearly suggested that then assumed you meant "under Arduino control", but 555's can output several
100mA which is good. And you can control the 555 with one of the pins to turn on and off (forget which).
allanhurst:
My copious array of databooks doesn't seem to detail the conductivity or themal mass of bees.
Filling that gap in human knowledge would probably earn an igNobel award! You could figure
an electrostatic discharge model for bees too, should they ever handle MOS devices!
I presume they've ruled out bee-venom harvesting as a cause of colony collapse disorder? Just
a thought.
A typical tennis racket fly 'zapper' generates a bit more than a kV - probably over the top.
Unfortunately a PAM8403 only generates about 10v p-p, so probably not enough.
But there must be a recycling store somewhere near you where you could pick up a secondhand 25W audio amp
for very little ... HIFI is probably not necessary for this application. If not there are many modules on eBay.
Or buy eg a 100uH toroidal inductor from ebay etc, and overwind with as many more turns of thin wire as a secondary necessary to generate the voltage you need, then drive with a 555. I think I bought 10 from china for about £2
Allan
25W audio amp sounds nice but it needs to be powered from 12v battery (or 6v) as far as I know audio amps are powered by 220V AC so it's not a great option.
Nikola19992:
25W audio amp sounds nice but it needs to be powered from 12v battery (or 6v) as far as I know audio amps are powered by 220V AC so it's not a great option.
They make waaaayy bigger than 25W audio amps that work off 12V. Look to the car stereo industry. Or maybe I'm missing something and we're talking about a different type of audio amp. If so, disregard.
allanhurst:
Or buy eg a 100uH toroidal inductor from ebay etc, and overwind with as many more turns of thin wire as a secondary necessary to generate the voltage you need, then drive with a 555. I think I bought 10 from china for about £2Allan
Winding more than a dozen turns on a toroid is very tedius - I'd recommend E-cores with bobbin, bobbins
are much easier to wind, unwind, rewind and experiment with. Something like EFD20/25/30 for instance,
seem to be available on eBay, just remember you need 2 clips, 2 cores (ungapped) and 1 bobbin to make
a transformer. And some EC wire of course (aka magnet wire).
What if I use boost converter to step up voltage to 30V DC and then make it AC?
Boost then H-bridge you mean? Yes, would work.
okay,it would work,but is it good idea?
Not very. Cumbersome. A small step-up transformer ( see posts above) and a little oscillator such as 555 is much more elegant.
Allan
yes but where am I going to get a transformer,and also,how should I change voltage on it? impossible as far as I know
Make one.
See posts above.
Allan
but I need to make like 10 of theese and they need to be same.