Re: Simple 555 PWM - disappointing performance

On Sun, 29 May 2005 14:43:11 GMT, "Ban" <bansuri@xxxxxx> wrote:

>Yeah, your last measurements confirm what almost everyone has noticed, the
>555 together with the 3055 are not up to the job. It was not only the power
>supply as you thought, but the whole concept.
>When making a motor controller, you first collect data on the motor, so 0.08
>ohms DC-resistance is the most important, because only with at least 25A you
>will reach the desired starting torque, no need to measure this
>mechanically. The number comes from your desciption of 2.4V supply with
>2NiCads in series.
>Just this single number will already give the amount of inadaequacy of your
>concept. No need to solder and measure much.
>It is a pity when so much thinking soldering and measuring is wasted to get
>an unusable circuit.
>When I make a little circuit like this, I want to have a better result than
>what can be commercially bought or at least equal, otherwise it would be
>smarter to buy a RC-racing car motor controller or some industrial circuit.
>How can a hobby be fun, if you arrive at the situation that you better had
>left this alone?

---
It's called experimentation, and the fun is often in the journey, not
necessarily in just getting to the destination with a cut-and-dried
solution.
---

>Your other responses also show that despite all the help here, you have not
>understood the function of a motor let alone the idea of PWM.
>It is not an insult if somebody expresses this, or do you want to become a
>Burridge? Better to read up a bit, with the Net giving so much useful
>information. When you feel insulted than just because I expressed what
>everyone else thought too, and I happened to press the button. :-))

---
Are you so thick that you can't understand that using derisive
language can't be construed as anything but an insult? Or gross
insensitivity? Go back and read what you wrote and try to think how
it would make you feel if you were in Terry's place and he was
pontificating about the inadequacy of your concept, your ignorance,
and about how you should be conducting _your_ hobby.
---

>What I consider insulting is when someone writes: His stupidity is so gross,
>that also here he chose a completly wrong concept, a waste of bandwidth
>etc.etc. compare that with my words above.

---
OK.

"Just this single number will already give the amount of inadaequacy
of your concept."

sounds to me to be very close to

"His stupidity is so gross, that also here he chose a completly wrong
concept."

Don't you agree?
---

>I apologize for suspecting that you found the circuit "on the Net", when you
>made it up yourself. Maybe a smaller motor will even do with it, despite the
>fact that there is no regulation, which requires some sort of feedback.
>Terry, take it easy. I just felt to express a bit of critics and you feel
>insulted? Have a good laugh and accept that, next time "JT" might press the
>button... I have heard the English humour is famous, look how Mr Atkinson
>can express it by making fun with himself.

---
Yes, but that's Mr. Atkinson poking fun at _himself_, not someone else
poking fun at or trying to ridicule him.

Something like if I wrote, "What's the thinnest book in the world?"
and _you_ replied, "Italian War Heroes" before _I_ did.
---

>Nevertheless I can appreciate
>your contribution to this group.
>I'm going swimming now, so I will have a nice sunday. You will see me
>passing on the left webcam in a couple of minutes.
>http://www.bordighera.it/Telecamere/tlc.html


--
John Fields
Professional Circuit Designer
.

Quantcast