On 2005-12-15, jimbo <jimREMOVE@xxxxxxxxxxxxx> wrote:
> Big voltages but relatively small current?
yes, if operating at 5W
> The suggestion of the horn tweeter appeals to me. Looks like 50W
> tweeters can be had for about $5 a piece from surplus sources. A
> cheap op-amp delivering less than 50W over a good frequency range
> might do the trick for initial testing--since I don't know what
> drilling rates commercial setups are achieving, I won't know how
> much better it could be. ;)
> Apologies for this naive question: Big voltages ... can they be
> done using voltage multipliers after the amplification stage? Um,
> a cursory glance at simple voltage multipliers gives a few
a transformer would be ideal. for working at 5W a 40KHz transformer
could probab;y be wound on a toroid from a dead computer PSU.
> 1) At what point (frequency and/or voltage) does the cost of
> suitable caps leave practical reality.
> 2) Are there diode issues, i.e. noise or voltage, that will impact
> the system at higher voltages?
> 3) Am I looking at voltage multiplier circuits that are too
yes, you need AC to drive the piezo, those capacitor-diode devices
produce DC. use a transformer.
> 4) For boosting the voltage (also at the expense of the current)
> what about a good old transformer operating in the low ultrasonic
> range? The smaller form-factor, the better, I'd assume.