DHT Heater using VCCS - PCB or Kit (Possible Group buy)
- pre65
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#586
1 Gnats Whisker = 0.000" to 0.005" or less (i.e. a light gap).
2 Gnats Whiskers = 1 Gnats todger
3 Gnats todger = A Gnats.
4 Gnats =a Tad
3 Tads = a Smidgen
YMMV
OR
Gnats dick.
An extremely small unit to measure things by, subdivided into a `gnat's dick-end', (about 8 to the gnat's dick), and a `gnat's cock-hair', (about 12 to the gnat's dick-end) thus giving an imperial scale of 96 divisions. This sort of accuracy is essential if you're trying to engineer the worlds best amplifier.
2 Gnats Whiskers = 1 Gnats todger
3 Gnats todger = A Gnats.
4 Gnats =a Tad
3 Tads = a Smidgen
YMMV
OR
Gnats dick.
An extremely small unit to measure things by, subdivided into a `gnat's dick-end', (about 8 to the gnat's dick), and a `gnat's cock-hair', (about 12 to the gnat's dick-end) thus giving an imperial scale of 96 divisions. This sort of accuracy is essential if you're trying to engineer the worlds best amplifier.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- pre65
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#588
Depends if it's a black, or white midge.Ali Tait wrote:Is a midgie's dick the same as a gnat's todger?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- Dave the bass
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#590
Any updates or thoughts Andrew? I can sub-in LD1084V in 1085's place 'fairly easily' as the amp is only a breadboard project at the mo.Dave the bass wrote:LD1085 in the BB's though innit, thats what's on the PCB legend? 1.78V across ip/op pins Andrew, AC i/p to BB is 6.38V AC, so a smidge higher than I'd bargained for. I'll experiment with a small trim down as suggested by Phil and see what happens here mindful of the whole thing falling out of regulation.
DTB
DTB
"The fat bourgeois and his doppelganger"
#592
Steve, did I miss you off? So sorry!!!Andrew wrote:Remaining folk to be delivered...
IPLS 4 + 4BB
Greg 4BB
Lynn Olson 4BB
Little Eddy 2BB
Richard H 2BB
Michaelvv 2 (not answering PMs)
Did I miss anyone?
Andrew
SS 2 + 2BB
I can bring to Owston for you?
Andrew
Analogue, the lost world that lies between 0 and 1.
- IslandPink
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#593
If you're there on Sunday afternoon then Owston is fine for me Andrew.
I'll try & tweak Lynn Olson to contact you .
I'll try & tweak Lynn Olson to contact you .
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#595
Andrew :
Couple of questions :
(i) what values of Rx , Ry should I be using for 20V-out on the big boards ?
(ii) If I'm using an SMPS at 24V DC coming in, could you just confirm where the best place for the +V would be to 'tap in' to the board. The ground connection/plane is fairly easy to see on the underside.
( Edit : maybe just use the + and - on any of the big cap positions ? )
(iii) If you have time could you add (i) and (ii) info to the 'Stacks' section, please ?
Couple of questions :
(i) what values of Rx , Ry should I be using for 20V-out on the big boards ?
(ii) If I'm using an SMPS at 24V DC coming in, could you just confirm where the best place for the +V would be to 'tap in' to the board. The ground connection/plane is fairly easy to see on the underside.
( Edit : maybe just use the + and - on any of the big cap positions ? )
(iii) If you have time could you add (i) and (ii) info to the 'Stacks' section, please ?
"Once you find out ... the Circumstances ; then you can go out"
#596
Its basically Vout = 2.5v(1 + Rx/Ry), something like 6k8/1k might be a good place to start.IslandPink wrote: (i) what values of Rx , Ry should I be using for 20V-out on the big boards ?
It's all in here. http://www.ti.com/lit/an/slva445/slva445.pdf
(ii) If I'm using an SMPS at 24V DC coming in, could you just confirm where the best place for the +V would be to 'tap in' to the board. The ground connection/plane is fairly easy to see on the underside.
Hold the board longwise, so the horizontal axis is the longest axis, make sure its face up, screen print in front of you, now make sure the diodes are in the top left hand corner. OK?
Right, now flip it over along the horizontal axis, do you see a 'T' block of polygon where the plus of two of the big caps are connected? The block of signal feeds the top pin of the voltage reg, I would pick one of those holes, probably the nearest one.
Will do.
( Edit : maybe just use the + and - on any of the big cap positions ? )
(iii) If you have time could you add (i) and (ii) info to the 'Stacks' section, please ?
Andrew
Analogue, the lost world that lies between 0 and 1.
- IslandPink
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- IslandPink
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- Joined: Tue May 29, 2007 7:01 pm
- Location: Denbigh, N.Wales
#598
Now, I need info on this bit. Is Rs a sense resistor and therefore in series with the filament - for measuring the current ?thomas wrote:......once I was reliably informed what I took to be links were in fact the sense resistors!...
Can I bridge this with wire if i don't need it ?
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#600
I'm not sure I understand the answer ....
Do I put a resistor in there ( if so what value ? ) or do I put in a piece of wire ?
Do I put a resistor in there ( if so what value ? ) or do I put in a piece of wire ?
"Once you find out ... the Circumstances ; then you can go out"