modulator Posted September 19, 2011 Report Share Posted September 19, 2011 Hello, I build two MB-6582, working perfectly. I have used psu option B and build my own psu with 5VDC und 9V AC (Tranformer 2x9V und 7805 with 3A max. ) Under full charge the 5V DC drops down to under 3V. I have tested this with 3 different power supply units (regulated power supplys) For both MB-6582 I need a no-load voltage of 8V. I am pretty sure there are no short-cuts etc. I did some current measurement and there are no uncommon currents. Any suggestions? Maybe because of the 2200uF Elko directly after the power-switch. Is this Elko really required? best regards Quote Link to comment Share on other sites More sharing options...
modulator Posted September 22, 2011 Author Report Share Posted September 22, 2011 (edited) - Edited September 22, 2011 by modulator Quote Link to comment Share on other sites More sharing options...
modulator Posted September 22, 2011 Author Report Share Posted September 22, 2011 (edited) I have one MB-6582 with 4x8580 and 4x6582 so I need only 9V. Second one has 4x6581 and 4x8580. Today I changed the psu option B of the "9V" MB to A because the 7812 generated some heat for nothing. But I got no change in voltage drop. Currents are (5V rail): 1. No CS (no lcd), without 9V-Jumpers for SIDs, Fan pluged on 9V AC Line: 0,8A 2. 9V-Jumpers pluged in, no CS: 1A 3. with CS : 1,1A Voltage drop increases with rising current. I need 7VDC so get a working MB with 5VDC in it. For this measurements I use no DIY psus etc. I did this with 3 no diy psus. The same behaviour at both MB. Edited September 22, 2011 by modulator Quote Link to comment Share on other sites More sharing options...
modulator Posted September 23, 2011 Author Report Share Posted September 23, 2011 Problem solved! Some miserable cable from pollin.de (20cm long => 0,8 Ohm x 2 = 1,6 Ohm) copper-diameter = 0,000001mm² :rolleyes: http://www.pollin.de/shop/dt/Nzg5OTYxOTk-/Messtechnik_Uhren/Messtechnik/Leitungen_Spitzen_Klemmen/Messleitungen_Set.html Buy nothing at pollin.de! Quote Link to comment Share on other sites More sharing options...
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