Something like this https://www.amazon.com/Alesis-SR-16-SR16-Power-Supply/dp/B08BJLRN9X?ref_=ast_sto_dp&th=1 On 19/06/2022 12:40 pm, Clockmeister wrote: > DC power packs are switch mode supplies but those with unregulated AC > output which are commonly available have a transformer. > > > On 19/06/2022 9:58 am, ocleide_at_earthlink.net wrote: >> That surprises me.....it seems like the most "commonly available" >> wall-warts these days use switching power supply >> circuitry..........maybe it differs by country? >> >> -----Original Message----- >> From: Clockmeister <clockmeister_at_internode.on.net> >> Sent: Saturday, June 18, 2022 8:51 PM >> To: cbm-hackers_at_musoftware.de; tokafondo@tokafondo.name >> Subject: Re: LM31T as AC voltage regulator for Commodore computers PSU >> >> 9VAC transformers are commonly available brand new in plug-packs >> (wall-warts) or as individual components from most electronics >> suppliers. >> >> >> >> On 19/06/2022 5:17 am, tokafondo_at_tokafondo.name wrote: >>> I will only say that this is an actual Commodore (and retro computers) >>> desert. And most 9V adapters I've ever seen are from xDSL routers, AP >>> and modems, long ago discarded. >>> >>> >>> >>> 18 de junio de 2022 22:12, "Mike Stein" <mhs.stein_at_gmail.com >>> <mailto:mhs.stein_at_gmail.com?to=%22Mike%20Stein%22%20<mhs.stein@gmail.com>>> >>> >>> escribió: >>> >>> Well, he's in Spain and you're in Italy; maybe you treasure the >>> old traditional ways more than he ;-) >>> I don't know offhand how constant the 9V load of a C64 is but I >>> would think that a carefully selected resistor with maybe a couple >>> of Zeners to clamp any overvoltage might do the trick. >>> m >>> On Sat, Jun 18, 2022 at 2:27 PM Francesco Messineo >>> <francesco.messineo_at_gmail.com >>> <mailto:francesco.messineo_at_gmail.com>> wrote: >>> >>> On Sat, Jun 18, 2022 at 5:42 PM <tokafondo_at_tokafondo.name >>> <mailto:tokafondo_at_tokafondo.name>> wrote: >>> > >>> > TI's version of the LM317T's datasheet has something >>> interesting to see in its page 15. >>> > >>> > It can be seen only in TI's datasheet, and not others AFAIK. >>> > >>> > They show how to use two LM317T IC in a way that from a >>> 12VAC source, take it down to 6VAC. I'm sure that with >>> changing the values of the resistors needed, 9VAC can be got, >>> instead of the 6VAC of the example. >>> >>> it is actually AC in the sense that there will be alternating >>> polarity >>> voltages, however that circuit will clamp the waveform voltage >>> to 9V >>> (or whatever you chose) as long as the input voltage is >>> greater than >>> the set voltage. So you'll get a kind of "flat-top" waveform. >>> I'd say it's not ideal (it adds high frequency harmonics, both >>> LM317 >>> need to be heatsinked...) >>> I have never had any difficulty in finding 9VAC transformers. >>> >>> Frank IZ8DWF >>> >>> >>> >> >> >> > >Received on 2022-06-19 07:00:49
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