SounDuke Posted May 13, 2005 Report Share Posted May 13, 2005 Hi, I purchased a 7805CV, looks like this is stopping me from powering MB64 with only a display and a few buttons and pots (ca. 200 mA) with 4 AAs. It is obvious since datasheet says that 7,5 V are required to mantain line regulation. Is there a 7805 which requires at least 6 V? I can't add 2 more AAs due to lacking space on case, I suppose a regulator with low power consumption exist since people who powers their MB with 4 AAs are a lot on this forum, can you give me an hint? Thanks! Quote Link to comment Share on other sites More sharing options...
atomsize Posted May 13, 2005 Report Share Posted May 13, 2005 A good way to get around that is to change the 4 AA batteries with a single 9V battery, that way you have enough power to get the machine working. By the way, use a Rechargable battery with more power, so you can always take care of the ambient :) Quote Link to comment Share on other sites More sharing options...
jamram Posted May 14, 2005 Report Share Posted May 14, 2005 Hi,normally voltage regulators are known that they need an input voltage thats about 1.5V for lm317 (up to 3V for 78xx types ) higher than the output voltage. Maybe the low drop voltage regulator LM2940 is a solution, but there is some extra circuit necessary (there are a lot of examples around in the www) but notice also: 1V difference between input and output is needed, too. Maybe it's enough to put a dull diode that can handle 200mA directly behind the battery or some z diodes... ... it would cause a drop of 0.6V (and then youre in the working limits for pic...)?greetinx, jamram Quote Link to comment Share on other sites More sharing options...
SounDuke Posted May 14, 2005 Author Report Share Posted May 14, 2005 I thought about using an lm family regulator, but finally I found space in my case and I added 2 more AAs :D Thanks anyway! Quote Link to comment Share on other sites More sharing options...
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