Fast zener diode substitute
in [Design]
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From: Phil Allison on 7 Feb 2010 00:20 "Banshee" > The article goes back to the seventies BTW ** The issue date is November 2004. There were no power MOSFETS in the '70s. > and was extensivly discussed and the circuit was considered pretty much > useless. ** Yep. Most battery charger / rejuvenator projects are useless scams. ..... Phil
From: Ban on 7 Feb 2010 01:04 "Phil Allison" <phil_a(a)tpg.com.au> schrieb im Newsbeitrag news:7t70t6F1kmU1(a)mid.individual.net... > > "Banshee" > > >> The article goes back to the seventies BTW > > > ** The issue date is November 2004. > It was then done with some power Darlington AFAIR, and that's where that zener came from. BTW IR launched its first power Mosfet in '79 > There were no power MOSFETS in the '70s. > > >> and was extensivly discussed and the circuit was considered pretty much >> useless. > > ** Yep. > > Most battery charger / rejuvenator projects are useless scams. > > > .... Phil > ciao Ban
From: Yvan on 7 Feb 2010 01:59 Nedavno Jamie napisa: > If D2 is the diode you are referring too, it's not a zener.. > it's fast recovery diode of 6 amps. > > I am going by the image of the GIF you posted earlier as you stated > it was the connected to the FET. You are looking at the wrong link. Look at my first post, and there is a link to PDF file, and there in the parts list: D5 = fast zener diode, e.g., BZT03 24V, 27V or 33V) -- ___ ____ /__/ / \ ** Registrovani korisnik Linuksa #291606 ** / / \/ /\ \ ** Registered Linux user #291606 ** /__/\____/--\__\ ** http://counter.li.org/ **
From: Yvan on 7 Feb 2010 02:32 Nedavno Ban napisa: >> I can not find this diode where I am, so can you suggest a >> substitute? I guess I can not just put regular 27V zener diode here? >> > > Yes put a 3-5W 27V zener. Local parts store only has ZY 27 (27V 1,3W), and ZX 27V (27V 10W) which is to expensive to buy for making something that may not work, just as a pastime. > If diodes use the zener effect, they are always very fast, because no > charge needs to be removed. This is valid for z-diodes above 8V > rating. The circuit discharges the battery, in one year with more than > 30Ah, together with the self discharge rate there will be 0 capacity > left after a year for a normal 45Ah, this is certainly not a good idea > and won't prolong battery life at all. I wouldn't let it connected for a year. Perhaps a month or two, and then recharge it. I used to do that, but as soon as the battery is out of the car, unused, it dies quickly. I tried to connect my charger to a timer that switched it on for a 20 min three times a week. Unfortunately timer died while I was away for a three weeks, car battery got charged all that time, and it died. > Better to get a trickle charger > and keep the battery fully charged during the storage time. What sort of voltage / current do I need? Do you have any links to a good proven trickle charger design? I've found different ones from small ones (like the ones for mobile phone), to 1A. But isn't 1A (when battery is fully charged) cause electrolyte to boil? -- ___ ____ /__/ / \ ** Registrovani korisnik Linuksa #291606 ** / / \/ /\ \ ** Registered Linux user #291606 ** /__/\____/--\__\ ** http://counter.li.org/ **
From: Ban on 7 Feb 2010 03:10
"Yvan" <killefitz(a)invalid.invalid> schrieb im Newsbeitrag news:hkloda$n61$1(a)news.eternal-september.org... > Nedavno Jamie napisa: > >> If D2 is the diode you are referring too, it's not a zener.. >> it's fast recovery diode of 6 amps. >> >> I am going by the image of the GIF you posted earlier as you stated >> it was the connected to the FET. > > You are looking at the wrong link. Look at my first post, and there is a > link to PDF file, and there in the parts list: > > D5 = fast zener diode, e.g., BZT03 24V, 27V or 33V)> > I also think this circuit can be dangerous. If there goes something wrong and that FET keeps conducting... ciao Ban |