SSE Power Supply Choke Resistance

[BillEpstein]

Building another Simple SE and want to use an enclosed choke. The original Triad is 150 Ohms. How crucial is the resistance? An 82 Ohm 5H be alright?

 

[ranhaber]

Building another Simple SE and want to use an enclosed choke. The original Triad is 150 Ohms. How crucial is the resistance? An 82 Ohm 5H be alright?

If I'm not mistaken it will effect you stables time and ripple for the B+.

 

[Triodethom]

go to Duncanamps and download pp2 it a free simulation works well just input the 82 vs 150 ohm on the choke . Off the top of my head 82 will give a bit higher voltage based on current across it .

 

[bobrown14]

You should be fine with a 5H 82Ohm choke... don't skimp on your capacitance in the PSU and you should be good to go. Keep your C1 in line with what type of rectifier you are using if it's a tube (5AR4 recommended) but you should beef up C2 and add the aux cap. I like to use a 470uF C2. I think I used 40uF C1 5H choke like you have and a 470uF C2 and my ripple was almost negligible using the PSUDII software mentioned.

In practice absolutely dead quiet noise floor. It's really a treat to (not) hear, it's crazy quiet.

Don't forget to twist up you heater wires nice and neat, you should be good.

Good luck with your build.

Cheers,
Bob

 

[hazard500]

Building another Simple SE and want to use an enclosed choke. The original Triad is 150 Ohms. How crucial is the resistance? An 82 Ohm 5H be alright?

If this is a true choke input (LC) then inductance is the first thing to look at.

eg as a rule of thumb, I work on the formula L (mH) > V/I (you can get exact formula from Allen Wright's cook book). this is the minimum inductance to maintain proper choke functioing ie constant current into the capcitor.

My amp is actually solid state Class A, but the methodology is identical. Secondary on the power tranny is 25 volts, so rail voltage (assuming no losses) is 22.5 V (secondary voltage * 0.9), quiescent current is 9 amps. So L (minimum) = 22.5/9 = 2.5 mH. To be conservative I use 6mH inductor. This has more resistance of course, and measured rail voltage is 19V.

So - first thing to do - what is your B+, what is current draw? Then work out your minimum L, hopefully it is less than 5H. Then work out voltage drop across the inductor to see if actual B+ is OK.

 

[BillEpstein]

You should be fine with a 5H 82Ohm choke... don't skimp on your capacitance in the PSU and you should be good to go. Keep your C1 in line with what type of rectifier you are using if it's a tube (5AR4 recommended) but you should beef up C2 and add the aux cap. I like to use a 470uF C2. I think I used 40uF C1 5H choke like you have and a 470uF C2 and my ripple was almost negligible using the PSUDII software mentioned.

In practice absolutely dead quiet noise floor. It's really a treat to (not) hear, it's crazy quiet.

Don't forget to twist up you heater wires nice and neat, you should be good.

Good luck with your build.

Cheers,
Bob

My 8th Grade Algebra One teacher gave me a passing grade for promising not to take Algebra 2, so PSUD is out.

If perchance the 82 Ohm part doesn't play nicely I could simply add a resistor in series?

It may not matter, I've discovered that a Cento Crushed Tomatoes can fits over the Triad just right.