Not nearly as much!
Not nearly as much!
It is the same.
With the same voltage and current (across the diode or resistor) the diode will dissipate exactly the same power as a resistor = voltage x current.
The point of using a diode instead or a resistor is to control the voltage drop which with a diode is roughly constant. It has nothing to do with their power dissipation characteristics.
Andrew
"Gregory Procter" wrote
Exactly as much except in special cases such as LEDs where a small part of the energy is transformed into light. If you can demonstrate otherwise, the world of science would most interested in an exception to the law of conservation of energy.
The term "back to back" in relation to diodes to everyone I know means in parallel in opposite directions. If you had read the posting you would have noted I stated "0.6v for each pair of diodes" so blind Fred knows that I am talking about TWO diodes that must have at least one conducting and also NOT two diodes in series. Serves me right for not keeping it totally SIMPLE !
"Brendan"
Thank you :-)
Jim.
yay, some1 agrees with me. hehe
Perhaps you need a telecoms background - it used to be a common term there.
In the 1st diagram above, it does work if the diodes are zener diodes. It lets you drop more volts without a huge number of diodes.
i was never having a go at u, so y the ...SIMPLE... coment? mayb u could've explained where it comes from. I was just trying to understand what u meant.
sorry for the rundeness, i was just pissed off at the time.
That is correct ..... Put in another pair in series and you get 1.2v and so on. The 0.6v or 1.2v etc is "consumed" by the diodes and reduces the voltage applied from the track to the motor by 0.6v for every diode you have (in the conducting direction) in series with the motor. WARNING === Do NOT connect in parallel to the motor. So the connection is .... track1 >> diodes >> motor >> track2 If you only have 1 diode ... the motor will only go 1 direction so the 2nd diode (reversed) is needed when you want the motor to run in the opposite direction. The 0.6v is just the properties of a silicon diode in the conducting direction. In the non conducting direction the diode is a very high resistance that blocks nearly all current flow. Most common (cheap) diodes are rated at 400v and 1 amp which is the max they can withstand to block (400v) and max current flow (1 Amp) without damage --- Usually called 1N4001 or similar in the catalogues. Germanium type diodes only drop 0.2v and are NOT suitable for this application as they cannot handle the current involved.
In message , Brendan writes
Next time you feel that way, why not consider sending you post to news:alt.test? Then we can be spared having to put up with an overwrought ocker trying to flaunt his ignorance.
You know, I can't think of the correct term for this circuit. In audio circles it is called a 'clipper' or 'limiter' when used in parallel with the signal.
How about 'bi-directional constant voltage dropper'?
Perhaps not!
David.
"David F." wrote in message news:3f228cb7 snipped-for-privacy@mk-nntp-2.news.uk.tiscali.com... : > yay, some1 agrees with me. hehe : : : You know, I can't think of the correct term for this : circuit. In audio circles it is called a 'clipper' or : 'limiter' when used in parallel with the signal. : : How about 'bi-directional constant voltage dropper'? : : Perhaps not! : : David. : : I recall a term "reverse parallel" for that diode configuration. "Anti parallel" as suggested by someone else works as well.
I avoid terms that are misleading, even if they are in "common usage".
The diodes were drawn with straight lines, meaning, in common usage that they are standard diodes.
And how do you know it is misleading if you use it all the time?
to
Thank you for providing a waste of electrons - your "drawing" was not required. Nowhere was it said that the orininal represented zeners.
Sheep won't come home tonite eh?
I understand what "back to back" means - diodes placed "back to back" block all current within their working voltage range.
Quote: "> > > > In the 1st diagram above, it does work if the diodes are zener diodes."
Sorry to hear that you're lonely.
Your understanding, many others understand different.
Now be a good kiwi and go and cry tend your sheep.
Do you have a particular reason for being personally offensive?
Perhaps he's Epperson's love child?
And who the f*ck is that?
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