Please read the description/textbox first. Part 3 of the project to make a simple stereo amplifier (say 2 x 1-1.5 Watt) with the ECL 80 triode-pentode.
Stereo tube amplifier with ECL 80 tubes part 1 (20 June 2022)
https://youtu.be/Kw8hp9mJBVE
Stereo tube amplifier with ECL 80 tubes part 2 (25 June 2022)
https://youtu.be/E99N0SY2tbo
Stereo tube amplifier with ECL 80 tubes part 3 (28 June 2022)
https://youtu.be/xHFsXzmEB9Q
In this video I show a circuit to make the anode (= plate) voltage via 4 diodes. Out of (say) 50 V AC (3-5 Watt). That anode voltage (DC) in general has to be in the order of 100 Volt DC to 180 Volts DC.
Diodes: 1N4007 rated for 1000 Volts at (say, only saying) 500 mA max. Every Si diode can be used, as long as its voltage is (say) 500-1000 V and its current is (say) max. 500 mA. These diodes (500 V or 1000 V types) are often rated for (max) 1 Amp, but that only works in the low voltage range, say max. 24 V. The internal resistance of a (say) classical/normal pentode (between anode-cathode, when working) is approx 4000 to 5000 Ohm. That means that the primary transformer coil in the anode lead must also be approx. 4000 Ohm. Transformer DC Ohms values in the anode lead to (+) are not very critical, at least for simple audio applications (say here the 1 Watt amp): DC resistances on such a transformer primary in the anode lead measure 2K-10K.
An anode voltage must be smooth, with the lowest hum (ripple out of the mains supply) as possible.
That can be realized with an RC or LC-filter, because the plate supply current is low, in the order of 5 mA-50 mA (in general).
I talk about tube amplifiers in the order of 1-5 Watt audio max, not higher, though the principles (showed in this textbox) are usable for other purposes, with higher audio outputs.
In 1920’s radio circuits the plate (anode) voltage was in the order of (between) 50 V DC and 120 V DC. They (in the early stages of the radio) supplied that anode voltage via (wet) batteries, that had to be charged every time.
There are (even now 2022) radio tube circuits that work properly with a plate voltage in a low or very low range, say in the 20-40 V DC (with a headphone, often). Read e.g. 1919’s -1930’s books on the website of worldradiohistory dot com.
Do you want more and practical info about radio tubes and how to use them? Go to the YT Channel of AllAmericanFiveRadio to learn more about how tubes and radio tube circuits work (Richard).
Link is here https://www.youtube.com/user/AllAmericanFiveRadio
And there are/were battery tubes in Europe, during the 1950’s/early 1960’s in the so called “D-series”, say the DAF XX etc. They worked on a filament voltage of 1,2 Volt and a plate (anode) voltage in the order of 40-60-100 Volts. They could be supplied by (dry or wet) batteries.
Receiver-transmitters with battery tubes were used in World war II by the the US Radio (Signal) corps, in (a kind of) portable radio’s/transmitters in the Shortwave range (3-8 MC). Portable, but quite heavy.
Anyway: this video only talks about how to make a plate voltage in the order of 150 V-200 V by using a 4 diode quadrupler circuit that can generate (example) out of 50 V AC (at 50 Hz or 60 Hz) an anode Voltage in the order of DC 180 V-200 V.
Please note: the output power (Wattage) stays the same (!), so when you use a 5 Watt transformer of 50 V AC, the output can be 4 x 50 V = 200 V DC, but only gives out 5 Watt or even lower, due to transformer loss.
So a high voltage with a current in the milli-Ampère range, but good enough (the wattage) to be used as a plate voltage for a tube amp. in the 1-3 Watt output audio range.
Hum can always be a problem, more info in the video. The easiest solution (not showed here) is a so called Pi filter for low frequencies: 2 capacitors in the order of 50 uF-470 uF (400 Volt DC) at the DC output (out of the quadrupler) with a resistor in the order of 50 Ohm-100 Ohm or even 470 Ohm in-between.
My You Tube channel trailer is here: https://youtu.be/xbgQ8T3oqh4 When you search, search always “NEWEST FIRST” to get the right overview. You can also search via the “looking glass” on my Channel trailer via keywords like ”audio”, “radio”, “amplifier”, “filter”, “Shortwave”, “transistor”, “FET”, “oscillator”, “generator”, “switch”, “schmitt trigger” etc; so the electronic subject you are interested in.
My books about electronics & analog radio technology are available via the website of "LULU”, search for author “Ko Tilman” there.
https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=Ko+Tilman
I keep all my YT videos constant actual, so the original video’s with the most recent information are always on YouTube. Search there, and avoid my circuits that are republished, re-arranged, re-edited on other websites, giving not probable re-wiring, etc. Some persons try to find gold via my circuits. I take distance from all these fake claims. I cannot help that these things happen. Upload 28 June 2022.