- 1. [Amps] AL1500 PSU design (score: 1)
- Author: f6irf@free.fr
- Date: Mon, 11 Jun 2007 14:54:38 +0200
- I recently bought a second-hand AL1500, and the PSU blew up when I turned it on the first time... (the amp was not used since 2002) On top of the burned 10ohms /10W resistor "starting resistor" in th
- /archives//html/Amps/2007-06/msg00075.html (7,788 bytes)
- 2. Re: [Amps] AL1500 PSU design (score: 1)
- Author: Karl-Arne Markström <sm0aom@telia.com>
- Date: Tue, 12 Jun 2007 10:01:57 +0200
- Since at every instant, the reverse voltage in the Graetz bridge circuit is divided over two series connected rectifier elements (2 x 5 1N5408's in this case), there is a small safety margin. Substit
- /archives//html/Amps/2007-06/msg00076.html (11,139 bytes)
- 3. Re: [Amps] AL1500 PSU design (score: 1)
- Author: f6irf@free.fr
- Date: Tue, 12 Jun 2007 10:36:52 +0200
- Karl-Arne Yes you are right: twice the peak AC voltage applies to full wave rectifiers with transformer middle-tap... so even the original 5x1N5408 should do the job... my mistake ! Guess that my hyp
- /archives//html/Amps/2007-06/msg00077.html (11,699 bytes)
- 4. Re: [Amps] AL1500 PSU design (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Tue, 12 Jun 2007 09:16:53 -0400
- I don't understand how you could charge the capacitors through 1M ohm 6 watts when the bleeder resistance is 400k ohms 56 watts. This would only charge the caps to 1/3 voltage. Also what was the vol
- /archives//html/Amps/2007-06/msg00078.html (9,939 bytes)
- 5. Re: [Amps] AL1500 PSU design (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Tue, 12 Jun 2007 17:49:26 -0400
- The new cap. assembly bleeder is 1.2 Mohms (12x 100k) so I was expecting the condensers to charge roughly at half the voltage - just for a first try... But I did not get the opportunity for a second
- /archives//html/Amps/2007-06/msg00080.html (8,247 bytes)
- 6. Re: [Amps] AL1500 PSU design (score: 1)
- Author: pat_f6irf <f6irf@free.fr>
- Date: Tue, 12 Jun 2007 20:39:37 +0000
- Tom W8JI a écrit : Hi Tom The new cap. assembly bleeder is 1.2 Mohms (12x 100k) so I was expecting the condensers to charge roughly at half the voltage - just for a first try... But I did not
- /archives//html/Amps/2007-06/msg00081.html (12,685 bytes)
- 7. Re: [Amps] AL1500 PSU design (score: 1)
- Author: pat_f6irf <f6irf@free.fr>
- Date: Wed, 13 Jun 2007 18:11:55 +0000
- Tom W8JI a écrit : Just what I had in the drawers - not a good reason ??? Tom, I won't blame you because you are defending your baby... it is a normal "mother" reaction... I am just trying to
- /archives//html/Amps/2007-06/msg00082.html (8,192 bytes)
- 8. Re: [Amps] AL1500 PSU design (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Wed, 13 Jun 2007 15:15:17 -0400
- Just what I had in the drawers - not a good reason ???>> Well I worry about two things. First the time to discharge the caps, but that isn't a concern if you don't care. The idea is to have the caps
- /archives//html/Amps/2007-06/msg00083.html (9,947 bytes)
- 9. Re: [Amps] AL1500 PSU design (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Wed, 13 Jun 2007 15:17:35 -0400
- Patrick Someone asked if you could be putting 240V on a 120 winding through a wiring error, and indeed you could be doing that. That was a good suggestion! Be sure you do not have a wiring error that
- /archives//html/Amps/2007-06/msg00084.html (7,986 bytes)
- 10. Re: [Amps] AL1500 PSU design (score: 1)
- Author: f6irf@free.fr
- Date: Thu, 14 Jun 2007 09:35:33 +0200
- Tom, The first thing I did after the first bang was to check the transformer. I found that it was wired for 220V, I rewired it for 240V according to the manual indications (I have around 235V +/-5V
- /archives//html/Amps/2007-06/msg00087.html (9,263 bytes)
- 11. Re: [Amps] AL1500 PSU design (score: 1)
- Author: f6irf@free.fr
- Date: Mon, 23 Jul 2007 12:15:37 +0200
- Just as a conclusion of my previous posts: - Replaced all diodes and capacitors on the rectifier board (used BY255, and new 2kV ceramic disk capacitors) - Installed a new capacitor board made of 12x
- /archives//html/Amps/2007-07/msg00366.html (9,103 bytes)
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