 | | 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)
|
| |
| | Re: lego cap, polarity, etc
|
|
(...) 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). (...) (24 years ago, 27-Mar-01, to lugnet.robotics)
|
| |
| | Re: lego cap, polarity, etc
|
|
(...) 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 (...) (24 years ago, 27-Mar-01, to lugnet.robotics)
|
| |
| | 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
|
|
That's right - it only needs to protect the capacitor from wrong polarity, but does not have to compensate. Maybe the instructions simply say "if it doesn't work, rotate the connector 90 degrees". Maybe the LED gives some indication if it is (...) (24 years ago, 28-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
|
|
No. DO NOT UNDER ANY CONDITION CONNECT AN ELECTROLYTIC (ie one with +/- on the terminals) IN REVERSE. The electrolyte is a high resistant in one direction only. The other direction is nearly a short. You may end up hurt as the capacitor blows up in (...) (24 years ago, 28-Mar-01, to lugnet.robotics)
|
| |
| | (canceled)
|
|
|
| |
| | Re: lego cap, polarity, etc
|
|
(...) The capacitor doesn't come with any instructions, at least not when purchased individually. The LED indicates when the capacitor is fully charged; when it reaches full charge, the LED begins flashing. I'm assuming at least one of the other (...) (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)
|
| |
| | Re: lego cap, polarity, etc
|
|
(...) <snip> The polarity markings Andy Gombos was referring to are printed on the LEGO-compatible package itself. The LEGO "capacitor" is in fact an electrolytic cap with plenty of support circuitry, and I assure you there is no danger of blowing (...) (24 years ago, 29-Mar-01, to lugnet.robotics)
|
| |
| | Re: lego cap, polarity, etc
|
|
(...) This is generally true, but not as dire as you make it sound. (...) Actually, electrolyte is a good conductor of electricity (in any direction). It comprises one of the terminals in an electrolytic capacitor. The other terminal is aluminum, (...) (24 years ago, 31-Mar-01, to lugnet.robotics)
|
