| dswiston |
Hey all. I'm working on a project of Rod Elliots, the new mosfet amp to be exact. Anyhow, I ordered a Basler transformer from apexjr and forgot to look and see if it was center tapped. Well its not but it has dual 50v outputs. So I put 'em in series to get a 50-0-50 output. However this results in about 70v across the filter caps. Now for the high power version of the project a +-70v is ok. However, I am making the "lower" power version and it looks like I'll have some problems with power dissipation. According to the specs, +-56v is the safe max for the low power version. So I would like to know if anyone has some simple ideas for how to cut the voltage down. The transformer has dual 50V taps, and from what else i can tell and for what its worth it has 10V, 20V, and 6.3V taps which look like they handle significantly less power than the 50v taps.
Thanks guys.
BTW, first post, yaya me! |
|
|
| officeboy |
dual 50v outputs is quite a bit the same as dual center tap, think of it as a 50-0-0-50.
The problem is that you are going to get 70V pretty much all the time. After rectification, your voltage goes up by about 40% (aka multiply original voltage by 1.414) That means your 50V is going to be 70V using full bridge rectification.
You might be able to unwind some of the secondary coils to lower the voltage a bit. Shoot for around 35V AC at the transformer to get 50V DC after
The below copy/paste is an excerpt from http://sound.westhost.com/project101.htm| code: |
AC Volts DC Volts VA Power (8 ohms)
20-0-20 +/-28V 100 40
25-0-25 +/-35V 100 50
30-0-20 +/-42 160 80
40-0-40 +/-56V 200 150
50-0-50 +/-70V 300 240
|
|
|
|
|