kevin gilmore Posted December 29, 2020 Report Posted December 29, 2020 (edited) you need AC 120v not 12v and that is for low bias only Edited December 29, 2020 by kevin gilmore 1 Quote
Vlaca Posted December 29, 2020 Report Posted December 29, 2020 Yes yes, i edited my post. Thank you! Yes i need low bias for my sr5-nb. Quote
Vlaca Posted December 29, 2020 Report Posted December 29, 2020 Here is the edited, right schematic(low bias): Thank you! Quote
ericj Posted January 28 Report Posted January 28 Necrobump! Was there ever an official published schematic for one of the SB transformer boxes? And if so can i have it? About the zener. There is some confusion to be sure. In the SRD-7 schematics, the part is listed as Z1100 and the symbol is very clearly a bidirectional zener, what would be commonly sold as a transient voltage suppressor today. There appear to have been parts called "Z1100" from a few companies and some of them were unidirectional. The component on the boards in my two SRD-7s has no stripe at all, just an "A" logo and Z1100. One end is slightly pointy but that is probably just sloppy epoxy work. Semitec made a Z1100 TVS diode until 2005. See attached datasheet. Littlefuse makes a P6KE100CA with similar specs. Given the nature of the SB energizers it may be that a unidirectional part works better in that circuit. Which is sort of why i would like to know if there was a published schematic. I don't have any SB energizers myself. SMTCD00017-27.pdf Quote
ericj Posted April 17 Report Posted April 17 (edited) OK, picked up a 7/SB on ebay for $50 + ship. Which was fair because this poor thing has had a hard life. There's rust, and wax melted out of the transformers. Yes, it's a unidirectional zener, marked 1Z100. My guess is that the current equivalent is ZY100 which will produce a voltage of about 83v at best, then 3x cockroft-walton and a 1uf reserve cap *before rather than after the ballast resistor, and the ballast resistor is 4.7M rather than the 2.2 or 3.3 specified in some of the wall-powered schematics. I'm pretty sure I've seen pictures of a 7/SB that had an additional transformer in the bias circuit but not this one, and the board looks identical to a gutshot of an SRD-6/SB i saw recently. I still think it's weird that i have yet to find a /SB official schematic. *shrug* maybe they never published one. Now i wonder what's in the fairly rare SRD-7/SBMK2. Edited April 18 by ericj corrected part number Quote
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