Power Supply

[Zeus_85]

Hello I would like to make a power supply, I have chosen to make this power supply 0-30 VDC STABILIZED POWER SUPPLY WITH CURRENT CONTROL 0.002-3 A

The thing is I can make it and copy it but I would like to know exactly how it works. I know some various components what they do but I get stumped when I try to follow the circiutry.
For example there is a filter with a resistor (1) and a capacitor (1) but they are in paralell, I thought it can only be in series for that to function. I have not seen in any book or site that they can operate in paralell.

I would very much appreciate if some1 could tell me how it works, or guide me and tell me what I should study so I can not just know how it work but also make improvements on it or design my own. I have bought an oscilloscope, soldering iron and a multimeter for this project. Would I need any other tools?
Thank you ever so much...

 

[pmac10]

i reckon your R1 and C1 are a smoothing circuit as i'm sure youre aware a full bridge rectifier connected to ac does not produce true DC but rather a ripple effect DC which is not suitable for all applications. in this case the 'reservoir' capacitor fills the gaps, if you like, between the peaks of the ripple DC waveform producing a smoother more DC like line.
as for tools, if you can 'aquire' a copy of National Instruments MultiSim, you can build the circuit on your computer screen and test with virtual instruments before you even bother physically building it.

 

[1ManRiot]

Site just loads blank for me but as above, sounds like a smoothing capactior of some description for a rectifier.

Does is look like this?





Rectifier - Wikipedia, the free encyclopedia

 

[Zeus_85]

Thank you for your replies. This is the schematic for the power supply. I have just learnt now that a parallel circuit of a capacitor and resistor smooths out the DC signal thanks to you guys and youtube . Just to be sure I know now that C1 and R1 is the smoothing circuit and R2 and C2 which is in series is the low pass filter. Does that mean that everytime a series circuit of a capacitor and resistor is a filter circuit and for a parallel configuration it is a smoothing circuit?

How should I go about learning how the rest of the circiut works? Thank you

Ps: If your wondering why I'm doing this, it is because I'm doing a course in aircraft engineering in uni and I want to improve on my practical side during the summer holiday...

 

[pmac10]

Hi Zeus, what your asking is no simple question, i would struggle to explain how that circuit works, what you need to do is understand what descret digital or anologue components do in their own right then work out what part they play in an electronic circuit (i'm no expert). do you know the difference between an NPN and PNP transistor? you've got 4 in there, do you know the characteristics of operational amplifiers, inverting and non, you've got three in there, when you know how these things behave you will be better equipped. i think i'm trying to say start at the basics and dont take this as condescending,as i'm crap at elecronics,
get 'Analogue Electronics' by John C Morris from Amazon for about a fiver, it brilliant with plenty of projects to build before you attempt the one in this thread.
by the way, what uni course is it? (i'm an ex RAF Aero Eng Tech)

 

[Zeus_85]

Hello Pman, I know how transistors work and I know the difference. Transistors in this ciruit are there for protection I think. I dont know exactly what an op amp is but hopefully I will learn that soon. I do need to do alot of work before I figure out exactly how this works.


I study Aircraft Maintenance Engineering at the University Of Glamorgan. I am doing the B1 license, and I'm doing all this so i can better improve myself in the electronics field, so I can do the B2 license. Which aircraft did you work on?

 

[pmac10]

your're a bit off the mark there Zeus with regards to transistors, transistors are the building blocks of all modern day electronics, in your circuit, PNP transistor Q3 for example will act as a dead end to current flow until a voltage is applied to the gate between R19 and R20, this will turn the transistor 'on' and current will flow to R22 and LED D12. when you talk of protection, i think you may be referring to diodes and more specifically zenner diodes, these will prevent incorrect current paths in electronic circuits.
as for your course, the B1 is an awesome tick in the box, that means you can sign off base maintenance right? i looked into it when i was leaving the RAF but was too expensive and i had no civvie 'type'.
i worked on Tornado GR1/4 for 9 years punctuated with a short spell on Chinook HC2, good times.