On 09/20/2012 09:43 PM, Marko Mäkelä wrote: > On Thu, Sep 20, 2012 at 05:31:42PM +0200, Gerrit Heitsch wrote: >> When I replaced the 7805 in my C16 with a switching regulator (*) and >> removed R10, the current before the regulator went down to 380mA when >> supplied with regulated 9V, with the original supply, it was 280mA >> since that is about 11V. This meant a LOT less heat in the box. >> Combined with CMOS-EPROMs instead of NMOS-ROMs and heatsinks on CPU, >> TED and PLA, I hope to have extended the livespan a fair bit. >> >> >> (*) RECOM R-78B5.0-1.5 drop in for a 7805. > > RECOM recently introduced the cost-reduced E series that might work here > too. Depends... The C16 needs close to 1A on 5V with the NMOS-ROMs, so to be on the safe side, I decided to use the 1.5A version. > The R-785.0-0.5 works like a charm, with a > tolerable ripple voltage (120mV at 4.4V when charging my phone). When > connected to a more stable power supply, the ripple should be a few mV > at most, and I guess the output would stay closer to 5V. That one is only good for 0.5A. Would be perfect for use in a C64 to replace the onboard 7805 though. But only if the ripple is really low enough so it doesn't show on the output signals since this regulator supplies VIC. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2012-09-20 20:00:54
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