B+ Voltage

[s2kov]

I was building the power supply using the 5AR4 rectifier tube. Using Duncan's PSU2 software, i was expecting a B+ of 300V using below configuration:

232V - 0 - 232V => 22uF => 5H => 47uF

Actual reading on DMM was measured at 329V.

Is the B+ voltage right? It supposed to be lower than that since there is a voltage drop on each plate of rectifier tube.

Appreciate your help....

 

[Frank Berry]

Did you put a load on the power supply?

 

[s2kov]

Not yet.

Did you put a load on the power supply?

 

[Frank Berry]

When you put a load on the supply, the voltage will fall.

 

[fdegrove]

Hi,

i was expecting a B+ of 300V using below configuration:

Having a 329VDC result under no load conditions is only 10% off, not bad in my book.

As our other Frank suggests the voltage will drop with a load attached.

Testing PSUs with no load attached isn't good practice and can be dangerous.

If later on you find to voltage to be off target you can always fiddle a little with the value of the first cap behind the rectifier or try a choke input filter.

Cheers,😉

 

[s2kov]

Hi,



As our other Frank suggests the voltage will drop with a load attached.





Cheers,😉

Will the voltage drop in the rectifier tube will happen during with load condition?

QUOTE]Originally posted by fdegrove


Testing PSUs with no load attached isn't good practice and can be dangerous.

[/QUOTE]

Oopppsss😱 😱 😱 Thanks for letting me know of this....

 

[JojoD818]

I see we have 2 Franks here. Pleasant day to both of you.

Kabayan!

Good thing your caps voltage rating wasn't exceeded when you tested your psu without load.

As always, safety first!

Goodluck,
JojoD

 

[s2kov]

JojoD,

Thanks for the reminder. Actually, caps voltage rating was based on VAC * 0.707 calculation but still there are rules that needs to be considered.

Regards.

Andy

I see we have 2 Franks here. Pleasant day to both of you.

Kabayan!

Good thing your caps voltage rating wasn't exceeded when you tested your psu without load.

As always, safety first!

Goodluck,
JojoD

 

[arnoldc]

wow! good thing you were not building a PSU with 420 B+ and 450V caps! without a load, it will....

 

[JojoD818]

wow! good thing you were not building a PSU with 420 B+ and 450V caps! without a load, it will....

That's why I always say to myself. SAFETY FIRST!

 

[ray_moth]

FWIW, I suspect that the parameters supplied for the 5AR4/GZ34 in PSUD2 are incorrect. For example, with a 6D22S as the rectifier I get a lower output voltage than with 5AR4. I would expect it to be the other way around, the 6D22S being known for its low voltage drop. Anyone else notice this?