OK, if it's a dance, we won't want to stop you!
But we advise - it is much easier to build a voltage regulator, like the Audio Note one in your drawing.
But if the Dance must not stop - yes, you need 0.3A for each 6922. Adjust the R1 for each heater, until you get 6.1 to 6.25V at pin 4 to 5, on each 6922.
If you make 4x CCS, you have 1.2A dc. Please check that your transformer is able to deliver MINIMUM 2.5A rms. OR it is rated 50VA or more. Also, capacitors after rectifier should be 2x 4700uF 25V/35V
I't not clear, I need four CCS for 2 tubes, or only two CCS one for each tube?
The Tx is 12V 5A = 60VA I mind is enough for 4 CCS, about PSU 2 x 4700 25/35V for each CCS?
The Tx is 12V 5A = 60VA I mind is enough for 4 CCS, about PSU 2 x 4700 25/35V for each CCS?
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For 2 tubes, need 2x CCS - each 0.3A (I thought you had 4 tubes).
You can run 2x CCS from 1x transformer, and 1x 4700uF will be enough for 2x CCS.
You can run 2x CCS from 1x transformer, and 1x 4700uF will be enough for 2x CCS.
will the voltage isolation limit of the heaters allow heater filaments to be series connected?
Two tubes/valves at low voltage could be run from a low voltage referenced CCS supplying 300mA to two series connected heaters.
Two tubes/valves at high voltage could be run from a high voltage referenced CCS supplying 300mA to two series connected heaters.
The two CCS would need separate secondary windings.
Since the CCS output voltage is ~12V then the input voltage should be ~22V. This can be achieved with 0-15 + 0-15Vac transformer 36VA (1.2Aac)
Again we are led up the Garden Path by a quarter of the brief being released.
Two tubes/valves at low voltage could be run from a low voltage referenced CCS supplying 300mA to two series connected heaters.
Two tubes/valves at high voltage could be run from a high voltage referenced CCS supplying 300mA to two series connected heaters.
The two CCS would need separate secondary windings.
Since the CCS output voltage is ~12V then the input voltage should be ~22V. This can be achieved with 0-15 + 0-15Vac transformer 36VA (1.2Aac)
Again we are led up the Garden Path by a quarter of the brief being released.
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Before start the new CCS I changed R1 for 16R5 & with one tube I get 6.20V & with the other tube I get 6.42V with the same CCS so my question is whats happen when both tubes are working shunt regulated? surely something goes bad not?
the heater that shows 6.2V is dissipating 6.2*0.295 = 1.83W
the other heater is dissipating 1.89W that's an extra 3.5%. Does it matter if one heater is 3.5% more heat output?
Now series connect these two heaters and the same 0.295A flows through both heaters and total voltage drop should be 12.62V (~6.3V/heater).
Both CCS: connected 1 Tx, R1 16R5 & dummy load 16R 25W
2nd CCS measurements:
DCin 14.89V
Across dummy load 4.65V
Across R1 4.70V (0.284A)
Across R2 5.90V
Across LEDs 9.07V
1st CCS measurements:
DCin 14.89V
Across dummy load 4.75V
Across R1 4.81V (0.291A)
Across R2 5.85V
Across LEDs 9V
2nd CCS measurements:
DCin 14.89V
Across dummy load 4.65V
Across R1 4.70V (0.284A)
Across R2 5.90V
Across LEDs 9.07V
1st CCS measurements:
DCin 14.89V
Across dummy load 4.75V
Across R1 4.81V (0.291A)
Across R2 5.85V
Across LEDs 9V
Thanks, now I will connect to the tubes & check if voltages are good & after the listening session🙂
Thanks Salas, first to change the current fortunately I have other tube so I has changed & now measurements are:
One tube 6.26V
The other tube 6.29V
🙂
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