Olle,
Yeah, Very happy to hear that you have found your hum source!
Shows professionalism on your part to keep at it until the problem was solved. Very, Very good for you!
Ron
Yeah, Very happy to hear that you have found your hum source!
Shows professionalism on your part to keep at it until the problem was solved. Very, Very good for you!
Ron
I've just been given a new power supply unit from a computer. Apparently something broke so the friend had it replaced and gave me the old.
I think it was just a fuse or resistor as he plugged it into 240 V when it was switched to 110V.
It's a good quality part with fan and many parts inside. Will have a further loook when I get home.
It has a 12 V DC outlet at 18 Amps (that seems too much)!! And 5 volts also. I will check them out.
Looking through the grill now, I see some regulators. Maybe many good parts I could use. I can't see or smell anything burnt.
Fan, led, switches also.😀 😀 😀 😀
and many wires. I will open it up and check it out.
I think it was just a fuse or resistor as he plugged it into 240 V when it was switched to 110V.
It's a good quality part with fan and many parts inside. Will have a further loook when I get home.
It has a 12 V DC outlet at 18 Amps (that seems too much)!! And 5 volts also. I will check them out.
Looking through the grill now, I see some regulators. Maybe many good parts I could use. I can't see or smell anything burnt.
Fan, led, switches also.😀 😀 😀 😀
and many wires. I will open it up and check it out.
Brit,
I have been saving my old power supplies for years.........I must have 5 or 6 of 'em laying on a shelf in the garage. Please start a new thread when you build this one up. (into whatever)
Here is a link to a "How to" for building a "Lab" powersupply.
Linkky
Ron
Someday I'll build one too. 🙄
I have been saving my old power supplies for years.........I must have 5 or 6 of 'em laying on a shelf in the garage. Please start a new thread when you build this one up. (into whatever)
Here is a link to a "How to" for building a "Lab" powersupply.
Linkky
Ron
Someday I'll build one too. 🙄
That´s great info thks Ron. Is it worth using a variac to test the heaters?
Could be useful if I want to get 6.3V out of the 12 or out of the 5V.
I thought it was much more important with the B+ voltage.
Any ideas for a home made Variac for a 275V supply?
I can´t afford to buy a variac here. They seem expensive.
?Olle: Did you test your B+ with the entire voltage on start up
Could be useful if I want to get 6.3V out of the 12 or out of the 5V.
I thought it was much more important with the B+ voltage.
Any ideas for a home made Variac for a 275V supply?
I can´t afford to buy a variac here. They seem expensive.
?Olle: Did you test your B+ with the entire voltage on start up
Yes I did! It's the way I usually do...Brit01 said:
About the computer PSU: If you want to test the heaters, why don't you do it with your filament transformer?
By the way, it's a good idea to wire up and test the heaters before all other components!
Twin the heater wires, and put them away from the signal circuit. Corners are good!
I use to twin them with my drill machine 😀
But why? Weren't you going to build Bas Hornemans aikido psu? It's a perfect psu for a Aikido! 😉
ollebolle said:
Agreed! The 6x5 rectifier tube comes on slow so if the voltage spikes way out of line.....say more than 350V you can turn off the power before any damage occurs. Just wire up the DVM and have a finger on the power switch.
Having said that a Variac is a great safety device.
Sorry they are so expensive there Brit. FleaBay?
Ron
Brit01 said:That´s great info thks Ron. Is it worth using a variac to test the heaters?
Could be useful if I want to get 6.3V out of the 12 or out of the 5V.
I thought it was much more important with the B+ voltage.
Any ideas for a home made Variac for a 275V supply?
I can´t afford to buy a variac here. They seem expensive.
?Olle: Did you test your B+ with the entire voltage on start up
Brit,
Here is one on UKEbay, I don't know the brand but the price is right!
UK
Ebay variac
Ron
Good to know. I will do that.
Sorry what do you mean by Twin the heater wires?😕 Twist you mean?
Yes i will use my new transformers and with Bas's psu. Just thought that I could use the pc power supply board if I need to test the heaters with DC and not AC.
Also it may have a good regulator on it that I could use in case I decide to use DC.
Sorry Ron I'm in Uruguay. We have a ripoffbay called mercadolibre.com.uy.
No cheap deals. It's not really the same. I buy loads of stuff from the UK, but all light stuff that my parents can send. A variac is not really an option.
The solder on these pc power boards are very tough.
I'm not managing to melt the solder!!! Did one joint but most are not melting.
What kind of solder do they use???
I'm not managing to melt the solder!!! Did one joint but most are not melting.
What kind of solder do they use???
Brit,
Try cleaning them off with some steel wool or a scouring pad. Then use some flux prior to (de)soldering. I dunno, it may be you have a dirty iron too. Wipe the tip on a wet sponge.
If you use steel wool make sure there are no leftovers prior to powering it up!
Ron
Try cleaning them off with some steel wool or a scouring pad. Then use some flux prior to (de)soldering. I dunno, it may be you have a dirty iron too. Wipe the tip on a wet sponge.
If you use steel wool make sure there are no leftovers prior to powering it up!
Ron
Yes! A clean tip on your soldering iron is important!
I think I meant twist 😉 Twist all ac wires like this:
I think I meant twist 😉 Twist all ac wires like this:
An externally hosted image should be here but it was not working when we last tested it.
Olle,
Fine examples of twists. I especially like the orange and blue together!
Doesn't hurt to twist the DC either.
Very nice job.
Ron
Fine examples of twists. I especially like the orange and blue together!
Doesn't hurt to twist the DC either.
Very nice job.
Ron
Did you use solid core for the heater cables? Easier to twist.
What diameter?
I managed to find the blown components on the pc power supply.
2 varisters.
241KD07
Totally burnt. These protected the other parts I guess.
Not sure if they are easy to get hold of here in Uruguay.
After some effort I managed to desolder them. Cleaned the joints very well with a fine wire brush, cleaned my iron tip (it's fairly new) and had to apply a lot of heat to get them lose.
Both wires on the picture are solid core. But my heater wires are not solid core... I didn't have enough for all wires...Brit01 said:
About the diameter: You don't need very thick cables. The cables on your atx power supply are just fine! 🙂
Hi Lars!
It will be hum-free soon! When I come home 🙂 I have been staying with my girlfriend for a couple of days, so nothing have been done with the amp 😉
I will make a good CRCRCRCRC supply, and then I'm sure it will be quiet 🙂
In fact it is almost quiet as it is now with my test-supply...
It will be hum-free soon! When I come home 🙂 I have been staying with my girlfriend for a couple of days, so nothing have been done with the amp 😉
I will make a good CRCRCRCRC supply, and then I'm sure it will be quiet 🙂
In fact it is almost quiet as it is now with my test-supply...