Found a PCB mount transformer at home: 10VA 2x15VAC
Put on a veroboard, not soldered anything yet.
If I put a rectifier bridge after and make it a small unregulated PSU, could I then connect SAA7220 regulator (and maybe more regulators) to it? Is the VA enough to support this?
Put on a veroboard, not soldered anything yet.
If I put a rectifier bridge after and make it a small unregulated PSU, could I then connect SAA7220 regulator (and maybe more regulators) to it? Is the VA enough to support this?
An externally hosted image should be here but it was not working when we last tested it.
Ok, a bit small then.
I also have one 12-0-12V 1500mA EI.
Tested the old regulated psu I found, but it wasn't accurate enough.
It has a 1-turn pot and was impossible to get closer then +- 0,5V when I aimed for 5V.
I have some 5K multiturn pots, but have forgotten how I built the psu in the first place.
Bottomside of the pcb looks like a birds nest, so trasing my steps I impossible.
I also have one 12-0-12V 1500mA EI.
Tested the old regulated psu I found, but it wasn't accurate enough.
It has a 1-turn pot and was impossible to get closer then +- 0,5V when I aimed for 5V.
I have some 5K multiturn pots, but have forgotten how I built the psu in the first place.
Bottomside of the pcb looks like a birds nest, so trasing my steps I impossible.
Ok
Is it small and relatively easy and cheap to build?
I have several lm350t, lm337 and some lm317 w heatsinks(on the way should arrive in 10 days or so).
Sounds great, my problem too...can't find schematics(maybe because I'm not sure what to look for).
Plz let me know if you find the schematic
I'll probably build an LM317 or LM350 regulator based on the schematics I posted earlier, atleast to begin with. The diodes in the circuit...can I use BYV95A as I have lots of those(I'll go through my boxes again to see what other diodes I might have).
Got the advice to put a Wima(?value) on pin24 of the SAA7220 +5Vdc ->wima(soldered directly on pin24).
When I adjust the voltage, how much can the voltage differ from 5,000Vdc? Of course I'l try to get as close as possible to precisely 5Vdc.
Ordered 6pcs Sanyo Low ESR 1000uF/25V to put under the pcb(2 each in parallell with 2703, 2713 and 2707).
Tomorrow I think the 22.000uF TSUP's arrive and I hope the DIP8 sockets arrive so that I can test my OPA2134 in the cd-60.
Then I'm just waiting for Rubycon 470uF (2704, 2714, 2715 and 2712), Axial 4,7uF/400V MKP's (2673, 2700) and some other bits.
Can I replace the 100uF electrolytes around the opamps to Rubycon 470uF too?
Got the advice to put a Wima(?value) on pin24 of the SAA7220 +5Vdc ->wima(soldered directly on pin24).
When I adjust the voltage, how much can the voltage differ from 5,000Vdc? Of course I'l try to get as close as possible to precisely 5Vdc.
Ordered 6pcs Sanyo Low ESR 1000uF/25V to put under the pcb(2 each in parallell with 2703, 2713 and 2707).
Tomorrow I think the 22.000uF TSUP's arrive and I hope the DIP8 sockets arrive so that I can test my OPA2134 in the cd-60.
Then I'm just waiting for Rubycon 470uF (2704, 2714, 2715 and 2712), Axial 4,7uF/400V MKP's (2673, 2700) and some other bits.
Can I replace the 100uF electrolytes around the opamps to Rubycon 470uF too?
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Sounds great, my problem too...can't find schematics(maybe because I'm not sure what to look for).
Plz let me know if you find the schematic
Found one!!!! Look in the previous post by Tubee!!! Its a link to a schematic for a reasonable reg using LM317. The LED's are used to set the ADJ voltage and the result is much lower noise than the usual std 317 reg config.
There is always the TPR I suggested. The diagram will be in the LM317 datasheet.
Check the advance reclocking document I linked to. Andrew also suggested the info was available here.
Mayday, You seem to be asking lots of questions but not really listening to the answers being given here which is a little frustrating. Most of the questions you have asked in the last 3 pages of posts have been answered in the first 7! Please slow down and read back through the thread.
Get rid of those ceramic caps on the TDA bit decoupling and refit those wima's again on their own and you'll hear what they are doing!!!
You wont get a high enough value film cap as a usable size. I think I suggested 470uF Rubycon ZLG (40p) here but you could try a solid polymer electrolytic (40p). I've previously used 2 x BG std 220uF on 7220 with excellent results but the costs are high. Otherwise you choose, Nichicon MUSE, Elna Silmic or Cerefine.....Caps often are a personal choice which is why I have here and previously suggested caps that are very low cost but extremely effective.
Found one!!!! Look in the previous post by Tubee!!! Its a link to a schematic for a reasonable reg using LM317. The LED's are used to set the ADJ voltage and the result is much lower noise than the usual std 317 reg config.
There is always the TPR I suggested. The diagram will be in the LM317 datasheet.
Check the advance reclocking document I linked to. Andrew also suggested the info was available here.
Mayday, You seem to be asking lots of questions but not really listening to the answers being given here which is a little frustrating. Most of the questions you have asked in the last 3 pages of posts have been answered in the first 7! Please slow down and read back through the thread.
Get rid of those ceramic caps on the TDA bit decoupling and refit those wima's again on their own and you'll hear what they are doing!!!
You're right. Will do
My worry is the 5000vdc
Where on earth is that coming from ?
Anton is right - and is saying again what I said when no one was responding at the start of the thread.
Slow down - your not taking it in and seem in an incredible hurry to do everything at once - you just can't - you'll eventually make a mistake and ruin it
Do it in logical steps and you'll do it better
There really are threads everywhere on this site relating to it all - ' SEARCH ' really works
Are you sleeping ?
You need to do this too !
My worry is the 5000vdc
Where on earth is that coming from ?
Anton is right - and is saying again what I said when no one was responding at the start of the thread.
Slow down - your not taking it in and seem in an incredible hurry to do everything at once - you just can't - you'll eventually make a mistake and ruin it
Do it in logical steps and you'll do it better
There really are threads everywhere on this site relating to it all - ' SEARCH ' really works
Are you sleeping ?
You need to do this too !
Not 5000, I ment 5Vdc with 3 decimals, how accurate I need to be.
You're right, sorry if I push to hard.
I'm perhaps overly eager to know what I need to know when I get the parts.
I do search, but I doubt myself and my ability to turn theoretical texts into actually applying them in real life. Don't want to go wrong.
I have (don't know the correct word) early retirement due to being to sick to work. So this is what I do when I'm not with the fiance or we are out with the dogs. I DO tend to get a bit manic about stuff, so I appreciate you letting me know when I become to much.
Anyhow, removed SMD's and fitted only wima's.
Took out 2707, and soldered leads in place so I can fit the TSUP tomorrow.
Cool, I suspect it was easier fitting those wima's the second time too
The 5v reg doesn't need to be exact. It's the noise on the psu thats important rather than the actiual voltage. Some of my regs run as low as 4.85v. This happens when you use fixed value components due to tolerances. That reg that Tubee linked to on PFM would be worth building as a starter. Only thing I would do is leave out the 10r on the supply.
Make sure you get the polarity right on that big cap! I normally use different coloured wires like red and black in order to avoid confusion.
The 5v reg doesn't need to be exact. It's the noise on the psu thats important rather than the actiual voltage. Some of my regs run as low as 4.85v. This happens when you use fixed value components due to tolerances. That reg that Tubee linked to on PFM would be worth building as a starter. Only thing I would do is leave out the 10r on the supply.
Make sure you get the polarity right on that big cap! I normally use different coloured wires like red and black in order to avoid confusion.
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