My module psu design

[davelectronic]

Hi to all.
I have posted my first offering of my modular psu project, looking forward to any comments, to this modest offering, and likewise really wanting to see other members on going projects.

 

[jackorocko]

You said that the rectifier was in the second module, but yet you also say that there is a 7805 in the first module to run the DC fan. So I am to expect that you back feed DC from the second module to the first module to run the DC fan?

 

[davelectronic]

My modular psu design

Hi Jackorocko.
Not sure whats going on why you cant post.
I know the projects section ie the building and updating is not suppose to be able for any one to reply to, rather there is a separate section for comments and discussion, and regarding the 7805 in the first unit, yes there is a center tap rectifier of the two diode configuration, and also a full wave four diode bridge rectifier in the second unit, mainly so i can power the second unit from another AC source if i wanted to, the first unit rectification allows a slightly under powered 40mm axial fan hence the 7805 for cooling, as i draw the maximum safe current from the first units transformer, so in a nut shell two rectifiers, the transformers voltage allowed the extra drop, so no reverse or back DC component there.

PS, I see whats happened now, ive posted in your other thread Jackorocko.

 

[davelectronic]

Where are all the projects ?

Hi to every one.
Its been a few days now, i was hoping to see some activity on some up and coming ongoing projects, where are they all, come on people, there must be some members that want to share there latest and greatest creation.

I live in hope of seeing some new gadgets projects.

 

[Raven Luni]

Possibly silly question: how did you get 6.2V from a 7805?



P.S. Your thread is nolonger alone

 

[davelectronic]

Add two rectifier diodes to the ground pin, each one adds approx 0.7 volts.

 

[davelectronic]

Thats an interesting one, robotics or similar.

 

[Raven Luni]

Ah - cool. Diode voltage drops are an interesting and useful property that I haven't had a proper look at

 

[niftynev]

nice project dave!

tha fact that you've separated the transformer from the regulator means there's gonna be a lot less heat in your regulator box to worry about. you're right about electrolytic capacitors & heat. & yet i still see commercial boards where electrolytic capacitors are mounted close to, or even touching a heatsink! if i was a sceptical type i might even think they did things like that deliberately! - planned obsolescence!

looks like your psu is gonna last forever though!

i like the cpu heatsink on the top of the case! a good spot to warm up a stubborn pen that won't write properly! lol!

the all-aluminium case is gonna be a great heatsink; i can't see it ever really getting much above ambient tremperature, especially if you're only expecting 2 amps from it.

what is the secondary voltage from the transformer that feeds your regulator dave? - that will have quite an effect on the temp at max currents.