Hello,
Try using a choke like the LL1694 or LL2733 from Lundahl. You probably need more mH and/or dcr otherwise there will still be charging peaks where with a true choke input the current running through the choke will be equal to the current taken by the load.
Greetings, Eduard
Try using a choke like the LL1694 or LL2733 from Lundahl. You probably need more mH and/or dcr otherwise there will still be charging peaks where with a true choke input the current running through the choke will be equal to the current taken by the load.
Greetings, Eduard
Hello Eduard,
But Lundahls haven't the required inductance:
20VAC x 1.41 = 28.2VDC
28.2VDC / 1.05A = 26.85
26.85 / 1000 (50Hz AC mains) = aprox. 27mH
But Lundahls haven't the required inductance:
20VAC x 1.41 = 28.2VDC
28.2VDC / 1.05A = 26.85
26.85 / 1000 (50Hz AC mains) = aprox. 27mH
Changed the choke resistance simulating LL2773, LL2751 & LL1694 and now PSUDII works OK, thank you.
Felipe
Felipe
Hello Catalonia,
You need some extra DCR and what you really need is more mH LL1694 is 160 mH and LL2733 can be made for about 500 mH. Lundahl allows you to order their chokes with different aircap. The standard LL2733 is 1,7A so if you tell them 1,2 A is enough you will get more mH which is a very good thing. greetings, eduard
You need some extra DCR and what you really need is more mH LL1694 is 160 mH and LL2733 can be made for about 500 mH. Lundahl allows you to order their chokes with different aircap. The standard LL2733 is 1,7A so if you tell them 1,2 A is enough you will get more mH which is a very good thing. greetings, eduard
Hello Eduard,
26 tube heater draws 1.05A. Yes, I know more mH are better because PSUDII show in the measurements.
LL1694 160mH 1.5A will be enough?
Cheers
Felip
26 tube heater draws 1.05A. Yes, I know more mH are better because PSUDII show in the measurements.
LL1694 160mH 1.5A will be enough?
Cheers
Felip
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Hello Felip,
Just a short answer. Yes, 1,2 A will be enough.
I am using LL2733 1,25A as choke input for my VT25A ( 7,5 volt 1,25A ) Rod Coleman supply. I am using LCRC ( R gives extra filtering and allows extra voltage adjustment)
Using Triad split bobbin transformer.
Greetings, Eduard
P.s always have some current running through a bleeder so it will always work as choke input even without any tube.
Just a short answer. Yes, 1,2 A will be enough.
I am using LL2733 1,25A as choke input for my VT25A ( 7,5 volt 1,25A ) Rod Coleman supply. I am using LCRC ( R gives extra filtering and allows extra voltage adjustment)
Using Triad split bobbin transformer.
Greetings, Eduard
P.s always have some current running through a bleeder so it will always work as choke input even without any tube.
Attachments
Hello,
Rod Coleman strongly recommends Triad split bobbin transformers for his designs.
They are not expensive and perfect for heater supplies.
Greetings, Eduard
Rod Coleman strongly recommends Triad split bobbin transformers for his designs.
They are not expensive and perfect for heater supplies.
Greetings, Eduard
![IMG_20200412_202441[1].jpg](/community/data/attachments/764/764644-1e724941b07515847e45d8278f571454.jpg?hash=HnJJQbB1FY)
![IMG_20200412_202442[1].jpg](/community/data/attachments/764/764655-5c620be0441c055fd74b9a5b8596d64a.jpg?hash=XGIL4EQcBV)
I also use Rod Coleman heater regulators, are very good & Rod is very kind supporting and sharing his knowledge.
Hello Felipe,
Yes, they are split bobbin too made in China.
The triads i have some made in China and some in Philippines.
I dont think there will be differences. Didnt know that Hammonds also made them. I bought the Triads because i also use them for 5 volt heater of 5r4gyb which is rectifying very high voltage so i want a 5 volt transformer that has high insulation.
If you use the right transformer, split bobbin, you only need to take care it can supply enough current 2A will be enough with choke input and then you get a Lundahl choke with 1,2 A current rating and lots of mH. Greetings, Eduard
Yes, they are split bobbin too made in China.
The triads i have some made in China and some in Philippines.
I dont think there will be differences. Didnt know that Hammonds also made them. I bought the Triads because i also use them for 5 volt heater of 5r4gyb which is rectifying very high voltage so i want a 5 volt transformer that has high insulation.
If you use the right transformer, split bobbin, you only need to take care it can supply enough current 2A will be enough with choke input and then you get a Lundahl choke with 1,2 A current rating and lots of mH. Greetings, Eduard
Thank you very much for all your suport, I will post the information in the 26 tube preamp so others can be know how to implement choke input PSU for Rod Coleman heaters regulators.
Happy Easter
Felipe
Happy Easter
Felipe
Hello Felipe,
Yes, Rod is always very helpful.SO he knows about my supply. I am using several high current chokes in my DDDAC too.
The best way to connect the lundahl chokes in what they common mode in their datasheets.
With the chokes you can use the SBYV28 diodes. They look small but because of the input choke they will have a very easy life!
Greetings, Eduard
Yes, Rod is always very helpful.SO he knows about my supply. I am using several high current chokes in my DDDAC too.
The best way to connect the lundahl chokes in what they common mode in their datasheets.
With the chokes you can use the SBYV28 diodes. They look small but because of the input choke they will have a very easy life!
Greetings, Eduard
Hello Felipe,
I read at the Rod Coleman document that the 26 tube is 1,5 volt 1,05A. The minimum voltage you must give to Coleman supply is 6 volt and the maximum is 8,2 volt ( this CAN be higher if you use a bigger heatsink)
And your simulation shows 14,5 volt output. I dont understand.
Greetings, Eduard.
( will reply your email very soon)
I read at the Rod Coleman document that the 26 tube is 1,5 volt 1,05A. The minimum voltage you must give to Coleman supply is 6 volt and the maximum is 8,2 volt ( this CAN be higher if you use a bigger heatsink)
And your simulation shows 14,5 volt output. I dont understand.
Greetings, Eduard.
( will reply your email very soon)