AC+DC adder to drive Piezo

Why would you or anyone need a d.c. piezo driver? I'm obviously missing something here.

Harry C.

snipped-for-privacy@gmail.com wrote:

these figures represent what?

connect the devices in series?

use a resistor network?

tell us what else you need first.

no idea what your problem is.

seems like a push-pull outyput stage is all that's needed...

Bye. Jasen

Thanks, that makes sense. I've seen similar things done in Mossbauer effect type work.

Harry C.

snipped-for-privacy@gmail.com wrote:

--- Please bottom post.

you say you bought an AC piezo driver, but you claim that it goes from zero to 20 volts, which makes it a DC piezo driver which can swing between zero and 20 volts.

Then you say that you have a DC piezo driver which can swing from zero to 150 volts, and that you want to add the outputs of both drivers.

From that I gather that you'd like to be able to, say, crank the

150V driver up to 150V and let the 20V driver ride on that, so the piezo would be seeing a signal varying from 150V to 170V at a 100kHz rate.

Is that what you want?

-- John Fields Professional Circuit Designer

Yes, correct.

John Fields wrote:

--- Then why, after I politely asked you to bottom post, as is the custom in these groups, did you so rudely top post?

You want free help but you want it on your own terms?

Maybe someone else will help you, but I won't.

-- John Fields Professional Circuit Designer

A simple capacitor/diode clamp circuit would seem to do

if both sources are ground referenced hook the DC source to one terminal and the AC source to the other end

Bye. Jasen

So whats up with the request to bottom post ..

what is convenient for some is a pain for others

when you have people that insist on posting the whole post of the previous poster, its a pain to have to scroll thru the history to get to a one line answer.

bottom posting never did make sense

snipped-for-privacy@aol.com wrote in :

--- When you're inconsiderate of others who may come to the thread some time after it started, then it may not seem to make much sense, even though it does. You don't read a book backwards, and it's inconsiderate to force others to read a series of articles chronologically backwards.

Even Google thinks so.

From:

"Summarize what you're following up.

When you click "Reply" under "show options" to follow up an existing article, Google Groups includes the full article in quotes, with the cursor at the top of the article. Tempting though it is to just start typing your message, please STOP and do two things first. Look at the quoted text and remove parts that are irrelevant. Then, go to the BOTTOM of the article and start typing there. Doing this makes it much easier for your readers to get through your post. They'll have a reminder of the relevant text before your comment, but won't have to re-read the entire article. And if your reply appears on a site before the original article does, they'll get the gist of what you're talking about."

--- BTW, speaking of being considerate, you need to clean up your punctuation as well as learn to top-post as the Romans do.

-- John Fields Professional Circuit Designer

It called "When in Rome...".

Stop being selfish--or find a Web-based forum.

They are (generally speaking) totally wrong and stupid.

That would be DIRECT evidence that the idiot who posted that doesn't know what he is doing. If someone does in fact need that much context (see below), he should probably be middle-posting (as I have done here).

When you see it done wrong, it's easy to ASSuME that. Do you constantly use the WORST examples you come across in your daily life as templates or consider them to be excuses for making up your own rules.

Here's the proper technique on Usenet:

1) TRIM OUT anything that does not DIRECTLY correspond to your response. 2) Make your addition BELOW that so that what results will read like a *dialog*

--not an event and a flashback.

it puts stuff in chronological (or conversation) order.

That's what the page-down key is for.

having to scroll to the bottom of the post to see what your talikng about and then back up to the message is worse.

Bye. Jasen