In Reply to: GZ34: getting too much voltage drop posted by banpuku on February 11, 2017 at 06:13:55:
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UPDATE: Resolved by vetmedrobert@gmail.com.You have 670 volts into a choke. the formula is VAC*0.45, or 670*0.45= 302.5 volts. This for a full wave rectifier as you have in your schematic. Then you must allow for the rectifier voltage drop which depends upon your circuit's current draw.
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I disagree.At the output of the filter: VDC=0.9*Vrms(trans. sec.) for choke input
At the output of the filter: VDC=1.41*Vrms(trans. sec.) for capacitor input
At the INPUT of the filter: Vrms(rectified) = Vrms(trans. sec.) - Vdrop of the rectifier.
In this case the potential at the rectifier's cathode should be 335V-15V or about 320V (GZ34 Vdrop = 16V at a draw of 200mA) and not 290V. Perhaps it's just a bad tube as in a low emission/transconductance specimen or the transformer has an issue. Did you verify that the no-load-voltage across both half's of the trans secondary is as specified?
Edits: 02/11/17
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Follow Ups
- RE: GZ34: getting too much voltage drop - sideliner 12:20:38 02/11/17 (6)
- RE: GZ34: getting too much voltage drop - Tre' 13:42:27 02/11/17 (5)
- RE: GZ34: getting too much voltage drop - sideliner 14:05:48 02/11/17 (2)
- RE: GZ34: getting too much voltage drop - Tre' 16:07:00 02/11/17 (1)
- RE: GZ34: getting too much voltage drop - sideliner 18:35:35 02/11/17 (0)
- here you go - Tre' 13:57:33 02/11/17 (1)
- RE: here you go - BenM 17:45:26 02/11/17 (0)