Subject:
|
Re: lego cap, polarity, etc
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Tue, 27 Mar 2001 23:28:30 GMT
|
Original-From:
|
Bruce Boyes <[bboyes@systronix.com]AntiSpam[]>
|
Viewed:
|
740 times
|
| |
|
|
At 15:01 3/27/2001 -0800, David Powell wrote:
>
>
> > A bridge only works with an AC input - it can't correct the polarity of a
> > DC input. So the Lego cap either has an AC input possibly through a
> > bridge or a DC input which is the correct polarity by means of its
> connectors.
>
> Uh, a bridge wouldn't be very good if it didn't handle inputs that
> switched polarities. A bridge should work just fine with a DC input of
> any polarity (of course for any DC input, only half of the bridge is
> actually being used).
Right, what I was trying to say is that a bridge can't 'invert' a DC input
of one polarity to make an output of another polarity - it can't "correct"
anything, a diode can only conduct or not conduct. All a bridge can do is
route the given DC input through one leg or the other of the bridge.
Bruce
------- WWW.SYSTRONIX.COM ----------
Real embedded Java and much more
High speed 8051 systems
+1-801-534-1017 Salt Lake City, USA
|
|
Message has 4 Replies:
 | | Re: lego cap, polarity, etc
|
| If I read correctly, it sounds as if there are + and - signs on the capacitor, which would imply that there is something that would block an incorrect polarity on the terminal. Maybe the diode and the 2 transistors on the board do this, I do not (...) (24 years ago, 27-Mar-01, to lugnet.robotics)
| | | Re: lego cap, polarity, etc
|
| (...) A couple of comments on this... An 'inverter' with respect to DC creates AC, it doesn't swap polarity. If you're going to use the term correctly always use 'invert polarity' and never 'invert' by itself. If you go into a store and ask for a (...) (24 years ago, 28-Mar-01, to lugnet.robotics)
| | | RE: lego cap, polarity, etc
|
| (...) Agreed - a bridge is not an inverter. Pardon this poor representation of the circuit: +---|<----+----|<---+ | | | | B (batt) | | | | +---|<----+----|<---+ | | +--------| |--------+ + (cap) The bridge is able to correctly 'route' the current to (...) (24 years ago, 28-Mar-01, to lugnet.robotics)
| | | RE: lego cap, polarity, etc
|
| (...) Yes, thanks for the sketch. Bruce ------- WWW.SYSTRONIX.COM ---...--- Real embedded Java and much more High speed 8051 systems +1-801-534-1017 Salt Lake City, USA (24 years ago, 28-Mar-01, to lugnet.robotics)
|
Message is in Reply To:
| | lego cap, polarity, etc
|
| (...) I don't have one, but can make some guesses. A bridge only works with an AC input - it can't correct the polarity of a DC input. So the Lego cap either has an AC input possibly through a bridge or a DC input which is the correct polarity by (...) (24 years ago, 27-Mar-01, to lugnet.robotics)
|
15 Messages in This Thread:
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
