Typical ESR values

Works fine for me, using wget and display.

cannot be displayed

he

I have had trouble and I have a very standard install. I'm on the wrong = =

computer to suggest the solution given to me.

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kHz.

llowed

Nice trick. I slapped in a 10uF 35 V tant.

~80mV or 80mV/10 *50 =3D0.4 ohms.

lotsa ringing at the step... What=92s that about? Bad technique on my part?

George H.

works for me?

Jamie

Put a 50 ohm R across your gen output..

Jamie

if

That ringing is about 40 MHz. The edge from my function generator probably isn't fast enough to excite something like that. Still, it's probably lead lengths or something causing all that ringing.

John

I find that some gen outputs have reactive circuits in them. Not properly terminated to bring the Q down to 1 or less.

Also, I've seen problems with lack of shoot through on complemary emitter followers as unity buffers on equipment exhibiting this effect.

A non reactive fixed load on the output normally fixes this. Ringing can be suppressed if the device that is delivering the signal has a high gain loop back and enough current handling to counter the reaction.

Many signal generators do not have feed back on their final stage to help the driving circuit maintain the output.

I've designed amplifiers to drive magnetic scan and focus coils and one of the items in the design is to have the amplifier attempt to counter act any reactive response, other wise, it'll show in the sweeps and focusing.

That's my take on it :)

Jamie

Does this work?

The web site needs work, and it's kind of a nuisance to throw files up onto. The FTP is really fast and easy, but some people can't see it.

John

The question mark indicates you don't know whether it does or not. Are you asking a question Dip S*it?

Do you have a lot of smokers in your work area? why is that scope so yellow? Or is that the natural color? my Rigol is near white.

btw, I have the 100mhz version, not the software hacked 50mhz, if that makes any difference?

Jamie

No. I'd never hire anybody who smokes.

why is that scope so

The Rigol is a little off-white, a faint cream color. Probably the camera is set for daylight mode or something. But you're supposed to be admiring the fabulous waveform, not the photography.

This one isn't hacked. Risetime measures 5.6 ns, which is a 63 MHz bandwidth. That's fine for most of what I do. If it's not, there's my

John

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Yeah, the sharp edge. I tried the x10 probe but there was too little signal and too much noise... pickup... My lab bench seems to live in a bath of 100MHz.

I was thinking after bad mouthing my x1 probes I now have to dig one out.

George H.

ESR

Now, the funny thing I've got right now: I have 8 channels in parallel, supplied from a single current-limited supply. But the thing is, if the current from 8 channels at full power, flows into one channel as fault current, that's four amperes more than it was designed to run... Ever had a case like this? What's the best way to handle it?

Tim

Yeah, forgot, the wave form looks nice ;) Jamie

I don't exactly understand the situation. Got a sketch?

Does this involve tantalum caps?

John

A description should suffice [rum disclaimer inserted here]:

Yes -- I have eight output transformers in parallel from the same current-limited PWM driver. Now, under normal conditions, all eight channels are working correctly, so the current shares evenly, and all the caps are happy (the maximum supply is 5A, so they each see a maximum of 5A / 8 =3D 0.6A peak, so the RMS ripple is under 0.42A, fine for a chip tantalum, though I have ceramic specified at the moment). But under fault, the whole 5A could flow into just one channel, which makes things "interesting". I may implement a "max-of-channels" current limit for this.

Tim

Have you tried this?

Once you sip this, cognac has no purpose any more.

I wouldn't use a tantalum cap here. Current is what detonates them. Stick with ceramics, or if you really need a lot of C, use a polymer aluminum.

John

Yes. These are much more user friendly to the outside world.

You should be able to throw files up onto your website by ftp if you want to and then publish their URL. Try creating a directory "temp" or even "ftp" on your website and treat it like you do with ftp:://

Then you can ftp stuff up and others can look at it how they like.

Regards, Martin Brown

Oooh, fancy. Looks like the Caribbean's answer to Makers Mark :)

Tim