Salas, could you advise me please. I have a Blue Edition board I am using for single rail +27-30Vdc phono stage. The phono stage pulls class A 20-30mA theoretically.
I have 2x MUR860 rectifier, 2x 2200uF 50v caps, 10Ω 5W resistor, heat sinks on IRFP9240s.
I am unsure what to do because the guide at the start of this thread is all in reference to the black boards which have different values, positions etc. and it's most confusing.
If you could take it slowly for me, I'd certainly appreciate it.
Many thanks
Lucas
I have 2x MUR860 rectifier, 2x 2200uF 50v caps, 10Ω 5W resistor, heat sinks on IRFP9240s.
I am unsure what to do because the guide at the start of this thread is all in reference to the black boards which have different values, positions etc. and it's most confusing.
If you could take it slowly for me, I'd certainly appreciate it.
Many thanks
Lucas
There are still the same 5 pads configuration to put the 2 leds and test/final resistor. 10R 5W places are clear and spacious in the Blue also. You need not to tweak that Jfet's legs, the blue is orthodox there, it goes straight in. There is mention for that in first post too. 1R resistor under Jfet translates directly mV to mA in the blue so to make your resistor decisions (1W for over 20V is better). What to write better again?
P.S. Stuff the positive side reg only, put those two leds and 3k3 1W instead of the test resistor, 10R 5W etc. Then if there is some Vout, I will ask you a couple of questions about some voltages to measure, so to get it spot on, if its too complicate for you at the moment.
P.S. Stuff the positive side reg only, put those two leds and 3k3 1W instead of the test resistor, 10R 5W etc. Then if there is some Vout, I will ask you a couple of questions about some voltages to measure, so to get it spot on, if its too complicate for you at the moment.
OK, my leds had a flat side different to the pcb drawing, so that confused me a bit, until I consulted the schematic to confirm I was leading with the +anode for the + side of the reg.
Some values are different. I have no 1Ω resistors. Can I use 10Ω as in the black version?
I also have no 220Ω resistors, so I will try with the 3K3 as you just mentioned and we will see what happens I guess.
Do I need an led bypass cap for test procedure, and if so, what value please?
Some values are different. I have no 1Ω resistors. Can I use 10Ω as in the black version?
I also have no 220Ω resistors, so I will try with the 3K3 as you just mentioned and we will see what happens I guess.
Do I need an led bypass cap for test procedure, and if so, what value please?
100uF. There are +/- marks. Don't use 10R instead of 1, just jumper it. We will judge by Vdrop3k3.
Ok. Powered up.
Smoking 10R 5W. Switched off after 5 seconds. Remained very hot. Nothing else hot that I could feel.
Doh!
Smoking 10R 5W. Switched off after 5 seconds. Remained very hot. Nothing else hot that I could feel.
Doh!
I might get some prizes for "most dicked around with Blue Edition DCB1 board". It is soldered neatly though
I have physically cut it in half and cut the B1 part off, unpicked must of the rectifier traces to make my 2x diode rectifier, and I preferred not to leave unused traces "hanging in space".
I tested it without a load at DC out. Is that a problem?
My mosfets are sinked with silicon grease only and aren't isolated with mica pads or anything. Is that the problem?
Many thanks
I have physically cut it in half and cut the B1 part off, unpicked must of the rectifier traces to make my 2x diode rectifier, and I preferred not to leave unused traces "hanging in space".
I tested it without a load at DC out. Is that a problem?
My mosfets are sinked with silicon grease only and aren't isolated with mica pads or anything. Is that the problem?
Many thanks
No leds lit up. Perhaps they are fried or reversed. It's possible. Drawing on the PCB has flat side at 90 degrees to flat sides on my leds (which are parts directly from the main BOM) so I have to work it out on schematic. I will check now and try to upload photo too.
OK I ran a 9v battery through the first string and it seems they are reversed.
Did nobody else find that the drawing depicted the flat side in an impossible position?
Did nobody else find that the drawing depicted the flat side in an impossible position?
Load is not a problem if drawing less enough than CCS setting. No load just more heat on the sink.
If the Mosfets have common metal between their backs and no isolation its a big problem.
Perhaps this will help.
How did you cut the board in half?
Don't feel bad Lucas, I can't figure out how to wire the Volume control.
maybe someone here will post a drawing.
How did you cut the board in half?
Don't feel bad Lucas, I can't figure out how to wire the Volume control.
maybe someone here will post a drawing.
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Salas, I've been so stumped over this and it is properly doing my head in. I am pulling my hair out. Last night I concluded that one of the following must be true:
1. I have literally LOST my mind
2. Wikipedia's LED page is nonsense
3. My LEDs not only have the flat side in a non-informative (neither anode nor cathode) position, but they're also impossibly reversed somehow.
4. The DCB1 Schematic I've been referring to is plain wrong regarding LED orientation.
Both schematic and D drawing suggest that the leds are oriented leading with the anode(+).
Fine, but my leds don't light up that way and the resistor overheats. I need to reverse them to get them to light. My wife says, fine, just do it that way then, if it works. Well, I didn't switch it on for long enough to confirm, because it's wrong, wrong wrong, and if nobody else has mentioned that the schematic and pcb are wrong, then I must have missed something pretty substantial. Perhaps my led is reversed. Jesus this is wrecking my brain! The more I check, the more sure I am!
http://en.wikipedia.org/wiki/Led
1. I have literally LOST my mind
2. Wikipedia's LED page is nonsense
3. My LEDs not only have the flat side in a non-informative (neither anode nor cathode) position, but they're also impossibly reversed somehow.
4. The DCB1 Schematic I've been referring to is plain wrong regarding LED orientation.
Both schematic and D drawing suggest that the leds are oriented leading with the anode(+).
Fine, but my leds don't light up that way and the resistor overheats. I need to reverse them to get them to light. My wife says, fine, just do it that way then, if it works. Well, I didn't switch it on for long enough to confirm, because it's wrong, wrong wrong, and if nobody else has mentioned that the schematic and pcb are wrong, then I must have missed something pretty substantial. Perhaps my led is reversed. Jesus this is wrecking my brain! The more I check, the more sure I am!
http://en.wikipedia.org/wiki/Led
Hi Lucas, it looks like you have been bizzy all night ?
-the short lead is the min of the led, the D symbol says that the flat side of the D is the short lead of the led.
-the short lead is the min of the led, the D symbol says that the flat side of the D is the short lead of the led.
all my >=5mm LEDs have all three ways of identifying + from -
the flat
the long/short leads
The small/big electrodes in the LED
My 3mm LEDs are missing the Flat.
So I tested them first using the long/short method across a 9V supply and a 2k resistor.
the flat
the long/short leads
The small/big electrodes in the LED
My 3mm LEDs are missing the Flat.
So I tested them first using the long/short method across a 9V supply and a 2k resistor.
Well you can identify the polarity by just showing it up to the light. The negative (cathode) side is larger, and has the actual diode attached, no?
Looking at the led insides is not a reliable method, the shape of anode/kathode is not always the same. Just stay at the fact that the short lead is the min.
It can always be that the leds are positioned in the right way, but that there is somewhere else a fault that prevents the leds from glowing.
It can always be that the leds are positioned in the right way, but that there is somewhere else a fault that prevents the leds from glowing.
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