farnell didn't have those exact values so i've gone with 160mA slow + 125mA fast for the dual supply and 1A slow + 500mA fast for the 5v supply. Are these ok?

 

Draw up a diagram from what you have

 

You can pop the output fast blows repeatedly and the primary power slow blow will probably never blow at all. The input slow blow in the screw top is good in a current controlled supply.

Even better than output fusing is some type of current protection circuit for the outputs, even a circuit that allows you to to set your current limit.

Look up Hall Effect sensors for the best ways but there are many ways to sense and control current.

 

Is this what you wanted?

 

That should do it.
Nicely done.

Good Job.

 

Excellent, thanks guys

I may look into adding fancy stuff like current limiting, variable voltage, etc later on, right now i'm still learning all this stuff so the simpler the better.

 

I would say drawing 100ma from each side would require 200ma. I do not think rms has much to do with the current, charge is charge.

 

I would say drawing 100ma from each side would require 200ma. I do not think rms has much to do with the current, charge is charge.

so what do u really think?
Open ur mind. We are here to help.

 

The current a cap draws isn't off the DC front. It effectively shorts the AC component and smooths the DC component. Capacitors shouldn't draw any load once they are charged (there will be a surge on power up), since they don't discharge except through the load (this is how they smooth the DC). The load is what is drawing the current, not the capacitors.

Submission: Power Supply Circuits

 

LTspice should include quite a few three-terminal regulator models (probably all LT corp parts, of course). Or you can find many others on the web, easily. I have two links that lead to tens of thousands of compatible p-spice models for all kinds of components, at http://www.fullnet.com/~tomg/gooteesp.htm . There is also a nice method for creating a spice model of a given power transformer, there, using only simple voltage and resistance measurements of the actual transformer (assuming you also have a variac and some power resistors). Having such a power transformer model can enable you to get a better idea of the startup and inrush behavior, for example, and should give a more-realistic simulation of rectifier transients, snubber behavior (if used), et al.

Anyway, one major thing with a regulated power supply is to make sure that the smoothing capacitance is large-enough to prevent the troughs of the ripple voltage waveform from causing the regulator's input minus output voltage to become less than its dropout voltage. The output can be quite ugly when that happens. You can use the simple equations at http://www.zen22142.zen.co.uk/Design/dcpsu.htm to calculate what capacitance is needed, for that. Make sure that you use worst-case assumptions for load current and low-line conditions (AC mains voltage 10% lower than spec, for example).