I can't seem to find this one elsewhere for some reason.
I know it's pretty basic stuff, but hey..
Basically, I want to learn the relationship between the AC from the transformer, the associated rectifier and the voltage that is produced.
Any good links? BTW - I have left my "Valve Amplifiers" book somewhere between Connecticut and Pittsburg, so I won't have that as a reference until I order a new one.
Thanks!
I know it's pretty basic stuff, but hey..
Basically, I want to learn the relationship between the AC from the transformer, the associated rectifier and the voltage that is produced.
Any good links? BTW - I have left my "Valve Amplifiers" book somewhere between Connecticut and Pittsburg, so I won't have that as a reference until I order a new one.
Thanks!
here's a rough model of what you do.
1. work out the HT voltage and current draw that you want.
2. work out the ripple that you can comfortably live with on the HT line, regulators may be of use here.
3. once you have the ripple you want, you can calculate the filtering you require.
4. I can get the eqations for you if you want.
5. once you have the L of the chokes etc, you can calculate the v drop across it using the R of the coil. make sure that the current limit of the choke is not overdun.
6. so what you now have is the voltage required at the output of the rectifier
7. find a suitable rectifier. that meets your current demands, PIV etc.
8. if using silicon, you can basically forget about voltage drop, all you have to worry is about dissipation, PIV and current draw.
9. if using tubes, find the voltage drop for your current, then add all the drops up, and you will come up with the total dc required at the op of a 'nominal no loss rectifier'.
10. divide that number by approx root 2, then you have the ac output of the transformer.
FWIW, get a copy of any old electronics book and it will go through this for you.
hope it helps.
bill
1. work out the HT voltage and current draw that you want.
2. work out the ripple that you can comfortably live with on the HT line, regulators may be of use here.
3. once you have the ripple you want, you can calculate the filtering you require.
4. I can get the eqations for you if you want.
5. once you have the L of the chokes etc, you can calculate the v drop across it using the R of the coil. make sure that the current limit of the choke is not overdun.
6. so what you now have is the voltage required at the output of the rectifier
7. find a suitable rectifier. that meets your current demands, PIV etc.
8. if using silicon, you can basically forget about voltage drop, all you have to worry is about dissipation, PIV and current draw.
9. if using tubes, find the voltage drop for your current, then add all the drops up, and you will come up with the total dc required at the op of a 'nominal no loss rectifier'.
10. divide that number by approx root 2, then you have the ac output of the transformer.
FWIW, get a copy of any old electronics book and it will go through this for you.
hope it helps.
bill
Thanks for the links, everyone. Thank you, Bill, for the reply as well. Maths would be helpful if you find the time.
I just want to add a few things.
I do feel pretty comfortable with valve audio circuits. I can read the schematics and, at a fundamental level, understand what's going on. Now, as I am (finally) getting ready to build my first totally-from-scratch rig, I am reminded that I haven't spent much time reading up on power supply circuitry. And, after having lost the first Morgan Jones book while running around New England this summer, I'm left to scour the 'net looking for bits and pieces of info that will help my project go smoothly. I'd like to order my trannies, but don't yet know exactly what I need. I know they'll be Hammonds, but that's about it. I'm going to build a dual mono version of Ian's PP EL84 (Baby Huey) amp - because it's an inexpensive circuit that seems to have pleased many, and either the 12B4 or Akido linestage (haven't yet decided).
And yes, I know about the lethal current involved with this hobby.
Thanks again for your replies.
Adam
I just want to add a few things.
I do feel pretty comfortable with valve audio circuits. I can read the schematics and, at a fundamental level, understand what's going on. Now, as I am (finally) getting ready to build my first totally-from-scratch rig, I am reminded that I haven't spent much time reading up on power supply circuitry. And, after having lost the first Morgan Jones book while running around New England this summer, I'm left to scour the 'net looking for bits and pieces of info that will help my project go smoothly. I'd like to order my trannies, but don't yet know exactly what I need. I know they'll be Hammonds, but that's about it. I'm going to build a dual mono version of Ian's PP EL84 (Baby Huey) amp - because it's an inexpensive circuit that seems to have pleased many, and either the 12B4 or Akido linestage (haven't yet decided).
And yes, I know about the lethal current involved with this hobby.
Thanks again for your replies.
Adam
leadbelly said:
Without load also a tube rectifier reach the Vac*sqrt(2) on the cap.
vice-versa with load on the rectifier he can also lose 40V @ 100 mA.
If there is also a choke of 8H it it is necessary to know the inside resistance.
I think that in this case it is better to create a model and to calculate
with SPICE
bye
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.