Okay,I go back to where it worked,the original CCS 300v/15mA,worked fine.My idea besides CCS for the Led´s(Do you have a suggested dessign-NPN-?)was direct coupling,that´s why the higher voltage 495v.
Will an RC filter be enough to bring the votage down to safe level(300v)or shall I use a SS regulator?
4.
😉
Will an RC filter be enough to bring the votage down to safe level(300v)or shall I use a SS regulator?
4.
😉Do you have a circuit simulator? I have created so much smoke on my computer that by rights I shouldn't be able to read the screen anymore. 
Ryssen said:
The NPN design is with the others in the earlier thread about CCS PCBs. A correctly-designed RC filter will be adequate to bring the voltage down to <300V (I would suggest 250V).
I repeat that you need to learn more about theory before attempting to modify designs. You can learn about "boring" theory or you can live with "exciting" explosions/smoke and destruction of expensive components. The choice is entirely yours...
Yes I know about the NPN CCS, I will try to implant it into this project of mine.
Yes you are right,I will read more
😉 more on the subjects,maybe I´m just in a hurry to get it done.😎 ....Suggest one.🙂
CircuitMaker.
Version 6 student edition is free (limited to 50 components at once) if it's still available. I use cm2000.
Version 6 student edition is free (limited to 50 components at once) if it's still available. I use cm2000.
Ehmm...little OT,trying LT spice,I can´t edit the Led Diode properties-gray field,how.And how do I get the symbol of a triod?I´ll bet it is an easy answer..😎
hi ryssen,
please visit duncan amps website for the models of the different devices. the site also has instructions for using a tube model.
When you click on Component from the toolbar, you selected a diode and it was labelled D1 D.
Now, insert the model entry for the diode, example 1N4004:
.MODEL D1N4004 D(IS=2.55E-9 RS=0.042 N=1.75 TT=5.76E-6 CJO=1.85E-11
+ VJ=0.75 M=0.333 BV=400 IBV=3.95E-5 )
Copy this text, press S on LT Spice to insert a Spice direcftive. Paste the text.
Then Right Click on the D label of your diode and type D1N4004 into the text box.
That's my OT answer 🙂
please visit duncan amps website for the models of the different devices. the site also has instructions for using a tube model.
When you click on Component from the toolbar, you selected a diode and it was labelled D1 D.
Now, insert the model entry for the diode, example 1N4004:
.MODEL D1N4004 D(IS=2.55E-9 RS=0.042 N=1.75 TT=5.76E-6 CJO=1.85E-11
+ VJ=0.75 M=0.333 BV=400 IBV=3.95E-5 )
Copy this text, press S on LT Spice to insert a Spice direcftive. Paste the text.
Then Right Click on the D label of your diode and type D1N4004 into the text box.
That's my OT answer 🙂
Back to topic... 😀
Sy, you think I can make a "red light district" PP EL34? I plan to change the cathode resistor of my EL34 PP amp with a bunch of red LEDs 🙂 35V / 1.5V = 24 red LEDs?
Sy, you think I can make a "red light district" PP EL34? I plan to change the cathode resistor of my EL34 PP amp with a bunch of red LEDs 🙂 35V / 1.5V = 24 red LEDs?
I thought of doing this. I baulked when I figured that if I wanted 10mA per LED, for 100mA I would need 10 strings of diodes (I don't have SY's experience here though).
Hi Indm, I'm running EL34 PP in AB1 so I must be in the same predicament.
Sigh... maybe I'll be lazy and just use a LM317 shared by both cathodes
Sigh... maybe I'll be lazy and just use a LM317 shared by both cathodes
EL34 might be pushing things because of the high bias voltage requirements, but it could be done. If you've got 34V requirement, that's 20 red LEDs per string. You'll need 10 strings to handle the current. Let's see, for a 6 ohm per-LED impedance (you can do better, but it takes some searching), that's 120 ohms per string. 10 in parallel gets you to 12 ohms impedance, a bit higher than you might want, but not unreasonable (Dynaco used a 15.6 ohm resistor in that spot). So, it's possible, but with 200 LEDs per channel, perhaps slightly over the top.
Or maybe not so over-the-top. At surplus, I've been getting my LEDs-of-choice for a little under 5 cents. So that's $10 per channel for a stable and reliable bias supply. Hmmmm......
Or maybe not so over-the-top. At surplus, I've been getting my LEDs-of-choice for a little under 5 cents. So that's $10 per channel for a stable and reliable bias supply. Hmmmm......
Maybe when I get the time to do the individual testing and compiled 400 😱 red LEDs, I'll do this.
Right now, there's no looking back for me. I changed my WE396A preamp to use LED on the cathode, and while it sounded good already with RC on the cathode, the LED puts it in a different league. I substituted the 2C51 and it sounded so good.
When I get back my 12B4, maybe I'll attempt the first step. I'll change its LM317 cathode current source with LEDs and check the difference. If I hear it then, I know what's the next step 😀
Right now, there's no looking back for me. I changed my WE396A preamp to use LED on the cathode, and while it sounded good already with RC on the cathode, the LED puts it in a different league. I substituted the 2C51 and it sounded so good.
When I get back my 12B4, maybe I'll attempt the first step. I'll change its LM317 cathode current source with LEDs and check the difference. If I hear it then, I know what's the next step 😀
SY, I think what you're describing is a modern stop light or the turn signal in an Escalade SUV. With gas approaching $3.00 maybe you could get an Escalade cheap and part it out for audio projects.
This from the guy who built a kilowatt transmitter to run a pair of Quads.
edit: Approacing? I'd kill to get gas for $3. Around here, $3.50 is about as cheap as it gets.
edit: Approacing? I'd kill to get gas for $3. Around here, $3.50 is about as cheap as it gets.
I paid PhP500 for 12.5 liters of 95 octane gasoline this morning. I'm glad I have a small CR-V 😀
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