kevin gilmore Posted March 28, 2017 Author Report Share Posted March 28, 2017 i don't remember ever picking elna caps, definitely did pick the wima caps will look when i get home Quote Link to comment Share on other sites More sharing options...
Pars Posted March 28, 2017 Report Share Posted March 28, 2017 Can't remember who posted the original BOM, don't think it was you.The Wima are pretty much the only ones that large cap in that small of footprint.Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Tinkerer Posted April 1, 2017 Report Share Posted April 1, 2017 (edited) Thought I would build my spare GRLV board and transformer into a 12VDC PSU for the little STAX amp. What value do I need for the R8/R9? Edited April 1, 2017 by Tinkerer Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted April 1, 2017 Author Report Share Posted April 1, 2017 I have never tried to get it to work that low, highly likely you have to use the 7V reference chip. Then it should work Quote Link to comment Share on other sites More sharing options...
Kerry Posted April 1, 2017 Report Share Posted April 1, 2017 Just built my mini GRLV supplies. The Negative came up just fine and works perfectly The positive supply is giving me some issues and I'll need to debug it. Here's some pictures... This pic shows a board I made for the Blue Hawaii that has the +5V, Digital Controller (ATMega328P) and Digital attenuator board along with the GR7/9xx regulators. I'll mount them once the positive supply is working. 9 Quote Link to comment Share on other sites More sharing options...
JoaMat Posted April 1, 2017 Report Share Posted April 1, 2017 Wow, very nice! Quote Link to comment Share on other sites More sharing options...
gepardcv Posted April 1, 2017 Report Share Posted April 1, 2017 What is the heatsinking story with these mini-GRLVs? Quote Link to comment Share on other sites More sharing options...
congo5 Posted April 1, 2017 Report Share Posted April 1, 2017 1 hour ago, gepardcv said: What is the heatsinking story with these mini-GRLVs? For low amperage/wattage like in pic above, copper on the board is the heatsink for higher power you can mount it to whatever size heatsink it needs. Quote Link to comment Share on other sites More sharing options...
gepardcv Posted April 7, 2017 Report Share Posted April 7, 2017 Well, I finally got around to making a GRLV. Three of them, actually. The positive rail works fine on all three, outputs perfect voltages (one +20V, two +30V, exactly as expected). The negative rail on all three outputs 0V. What's a good place in the circuit to start digging? Quote Link to comment Share on other sites More sharing options...
mwl168 Posted April 8, 2017 Report Share Posted April 8, 2017 Can you post a close up photo of the negative side? Quote Link to comment Share on other sites More sharing options...
congo5 Posted April 8, 2017 Report Share Posted April 8, 2017 what is voltage of collector on MJW21193? and base? emitter? Quote Link to comment Share on other sites More sharing options...
gepardcv Posted April 8, 2017 Report Share Posted April 8, 2017 On MJW21193, emitter voltage is 0, collector 0.117V, base 0.012V. Picture attached. I'm using a center-tapped transformer winding, so just one bridge. Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 8, 2017 Report Share Posted April 8, 2017 I assume there is a trace to connect the second output from the rectifier so what is the raw DC on the input cap? Quote Link to comment Share on other sites More sharing options...
congo5 Posted April 8, 2017 Report Share Posted April 8, 2017 The main storage cap connects directly to bridge rectifier and collector so .1v bad bridge or no connection to transformer? That board is nice and clean! What is ACV at terminal block? the voltage is not making it through the first two inches............ Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 8, 2017 Report Share Posted April 8, 2017 Hehe didn't read what was above the pic... Yeah has to be a bad connection... Quote Link to comment Share on other sites More sharing options...
congo5 Posted April 8, 2017 Report Share Posted April 8, 2017 just stating fact, the best I know, not to infer anything there should be continuity between collector and pin of bridge closest to input connector and second pin of rectifier to transformer input a dead short like a bad cap would make the transformer unhappy, buzz and hot. I assume that isn't the case. usually its a very simple cause, but hard enough when its in front of you to find. I have one that is a bit noisy, like 5v of ripple at 80hz, I did the layout so you know where the problem stems from. Quote Link to comment Share on other sites More sharing options...
Tinkerer Posted April 8, 2017 Report Share Posted April 8, 2017 Probably the trace on the top of the board for the bridge, that last leg closest to the AC input. Quote Link to comment Share on other sites More sharing options...
gepardcv Posted April 8, 2017 Report Share Posted April 8, 2017 Interesting! I'm measuring no continuity between the collector of the MJW21193 and the bridge leg closest to the AC input. Would that explain it? In which case I guess I should just jumper those two points? Quote Link to comment Share on other sites More sharing options...
cspirou Posted April 8, 2017 Report Share Posted April 8, 2017 Since it's all three I would say it's a bad PCB? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted April 8, 2017 Author Report Share Posted April 8, 2017 highly unlikely the board is bad maybe you are connecting the transformer to the wrong place, center tap of transformer goes to the middle pin and for single bridge the other 2 wires go next to the center pin if there is no raw dc voltage on either of the main power caps, the bridge is toast or not the correct type for this board Quote Link to comment Share on other sites More sharing options...
congo5 Posted April 8, 2017 Report Share Posted April 8, 2017 (edited) transformer input vac? blue to pink, and each to green? (center three) brown trace connects though via on right bridge footprint? 7 hours ago, gepardcv said: In which case I guess I should just jumper those two points? Lets find out where the break is first. is it just the via? that is easy to fix. Edited April 8, 2017 by congo5 Quote Link to comment Share on other sites More sharing options...
congo5 Posted April 8, 2017 Report Share Posted April 8, 2017 when using single bridge it seems like a good idea to solder a wire in that one hole rather than rely on the through hole plating Quote Link to comment Share on other sites More sharing options...
Tinkerer Posted April 8, 2017 Report Share Posted April 8, 2017 The problem with the single bridge on my boards (blue ones from the last GB) was the holes were smaller than the side ones so you had to drill it out to fit. I left the bridge lifted up a bit from the board so I could solder that top board trace from the top side to be sure it was connected right. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted April 8, 2017 Author Report Share Posted April 8, 2017 why no one tell me I got the wrong hole size... updated goldenreference6d file. 1 Quote Link to comment Share on other sites More sharing options...
Pars Posted April 8, 2017 Report Share Posted April 8, 2017 It was mentioned in the group buy thread, but not here. Our bad Quote Link to comment Share on other sites More sharing options...
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