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Old 4th August 2010, 02:50 PM   #281
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Quote:
Originally Posted by tangmonster View Post
R1 = 22r = 16V drop
R1 = 1k = 67V drop

R1 = 500R 20W= 35V drop = 65C
irf840 = 50C
irf9610 = 60C

I suppose i am going to

Is 60C ok for irf9610? or is it too high?
60 C , it is ok for 9610, 840
how many voltage drop Irf 9610??
And you AC = ???
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Last edited by quanghao; 4th August 2010 at 03:02 PM.
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Old 4th August 2010, 02:59 PM   #282
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yes , but my transformer is sitting at 57C due to all the wasted heat.
lm317 sitting at 75C

I am going to have to lower primary voltage or get different transformer

sigh

230V ac and 9v AC is WAY to high for this circuit.....
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Old 4th August 2010, 03:12 PM   #283
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Quote:
Originally Posted by tangmonster View Post
yes , but my transformer is sitting at 57C due to all the wasted heat.
lm317 sitting at 75C

I am going to have to lower primary voltage or get different transformer

sigh

230V ac and 9v AC is WAY to high for this circuit.....
yes! 230vAC~290VDC, so R1= 50V, and 9610 = 40V drop, i calculate max for it!
and now i use that! You can down VAC min = 200V, so down R1, it is low
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Old 4th August 2010, 03:17 PM   #284
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Quote:
Originally Posted by quanghao View Post
yes, it is ok. 230 x 1.28 = 294v, +b need 200 v , i= 40ma, ok,
you said it was ok!!!!!!!!!!

Don"t look for excuses now!!!???
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Old 4th August 2010, 03:21 PM   #285
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ALL YOUR DRAWINGS SHOW 220 to 250V AC???????

Heater circuit 7 to 9V AC???
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File Type: jpg Cricuit-SSHV-for-PhonoASH.jpg (210.6 KB, 348 views)
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Old 4th August 2010, 03:40 PM   #286
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Hello Andrea,
I'm building the circuit, but I'm thinking about the change of the anode resistors (//22K) with a ccs like cascode DN2540.
What do you think about? The Riaa circuit needs any adjustement?
Thanks a lot for you help.
Ciao
Guglielmo
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Old 4th August 2010, 09:10 PM   #287
pred is offline pred  Switzerland
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In my days it was 230VAC is 320VDC (factor of 1.41) but maybe this changed over time I think it is too high

For heater you need min 7V since it is 9.87VDC-1.5V drop for diodes so you get 8.3. So then you will have minimum required drop for LM317 that is 2V.

Pred

Last edited by pred; 4th August 2010 at 09:14 PM.
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Old 5th August 2010, 01:41 AM   #288
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Hi tangmonster, and all!
Well I have calculated wrong for you, I apologize, thank you just for me!
Hope you always help me find my mistakes, to my product for you to be more perfect.
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Old 5th August 2010, 01:46 AM   #289
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Default Use center transformer for SSHV

Use center transformer for SSHV
if you have transformer: 200-0-200 V you can use PCB
you se in the image
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Old 5th August 2010, 06:22 AM   #290
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200V Ac will give 282V dc That is still a 82V drop.

I think you can safely drop the 200Vac to 180Vac(254Vdc)


With 9Vac my lm317 is sitting at 75C which is too high. Using a 6.7c/w heatsink.


Long story short I will need to get a different transformer......

170Vac and 7Vac should do nicely

For now I am going to experiment with a 10ohm 50W resistor on the primary of the transformer to drop input and output voltages

170Vac and 7Vac should do nicely
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