Ping Sy: LED for Cathode Bias - Page 11

Ryssen · 9th May 2006, 05:03 PM

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.

lndm · 9th May 2006, 11:49 PM

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.

EC8010 · 10th May 2006, 01:14 AM

Quote:

Originally posted by Ryssen
My idea besides CCS for the LEDs, (do you have a suggested design - 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?

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...

Ryssen · 10th May 2006, 08:14 AM

Quote:

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).

Yes I know about the NPN CCS, I will try to implant it into this project of mine.

Quote:

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 you are right,I will read more

more on the subjects,maybe I´m just in a hurry to get it done.

....

Quote:

Do you have a circuit simulator?

Suggest one.

arnoldc · 10th May 2006, 08:25 AM

Simulators -

LT SPice from Switchcad

Simetrix from Cadena

and a couple more...

lndm · 10th May 2006, 08:36 AM

CircuitMaker.

Version 6 student edition is free (limited to 50 components at once) if it's still available. I use cm2000.

Ryssen · 10th May 2006, 05:03 PM

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..

arnoldc · 11th May 2006, 12:42 AM

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

arnoldc · 11th May 2006, 08:03 AM

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?

lndm · 11th May 2006, 08:47 AM

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).

9th May 2006, 05:03 PM	#101
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	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. __________________ Regards Åke

10th May 2006, 05:03 PM	#107
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	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.. __________________ Regards Åke

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9th May 2006, 11:49 PM	#102
lndm diyAudio Member Join Date: Mar 2006 Location: nsw	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.

10th May 2006, 08:25 AM	#105
arnoldc diyAudio Member Join Date: Apr 2003 Location: Makati	Simulators - LT SPice from Switchcad Simetrix from Cadena and a couple more...

10th May 2006, 08:36 AM	#106
lndm diyAudio Member Join Date: Mar 2006 Location: nsw	CircuitMaker. Version 6 student edition is free (limited to 50 components at once) if it's still available. I use cm2000.

11th May 2006, 12:42 AM	#108
arnoldc diyAudio Member Join Date: Apr 2003 Location: Makati	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

11th May 2006, 08:03 AM	#109
arnoldc diyAudio Member Join Date: Apr 2003 Location: Makati	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?

11th May 2006, 08:47 AM	#110
lndm diyAudio Member Join Date: Mar 2006 Location: nsw	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).

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