AC Mains to DC? Then to buck converter for high amp dc output?

[SittingBear]

Hey EEVBlog community,
I've recently been reading through the Fundamentals of Power Electronics and was interested, due to work projects as well, in getting to understand buck-boost converters more easily. There are such a vast quantity of ranges and specifications available from DC-DC regulation ICs with feedback pins it's easy to get lost in the capabilities and in the assumptions datasheet author's make the reader will know. In the sea of all of these ICs I have only found a few which provide comprehensible equations and explanations.

I'm mainly looking to understand how pre-made buck/boost converters work in order to better understand choosing one that works for my needs, or designing my own (more expensive). If it helps any my goal would be to convert some input to a solid 24V capable of feeding a <1.5A load.

I've also not found out much about other safe methods with a transformer other than a full-wave rectifier with a large output capacitor. Are there any alternatives which also use a transformer which may be useful? I do not plan on going transformerless as I am not comfortable enough to design a circuit which is not isolated and live.

I do not wish to use a linear regulator as they can be horribly inefficient and get extremely hot in the amount of heat they need to dissipate along with not being able to drive >1A loads typically.


Any help or advice is greatly appreciated! Thanks!

[johansen]

forward, flyback, fullwave, half wave, pushpull, all utilize a transformer to deal with the voltage conversion.
in fact you can make isolated versions of the cuk and sepic converter as well.
--the difference is where, and how, the energy is stored in the circuit to deal with:
1)varying load (resistive losses everywhere)
2) varying input and/or output voltage

if you just want a 24vdc smps.. why not buy one? you are up against a lot of established technology and methodology here.

the more expensive converters use a power factor boost converter to first convert rectified ac mains to 400 volts dc, then send it through the system.

[SittingBear]

forward, flyback, fullwave, half wave, pushpull, all utilize a transformer to deal with the voltage conversion.
in fact you can make isolated versions of the cuk and sepic converter as well.
--the difference is where, and how, the energy is stored in the circuit to deal with:
1)varying load (resistive losses everywhere)
2) varying input and/or output voltage

if you just want a 24vdc smps.. why not buy one? you are up against a lot of established technology and methodology here.

the more expensive converters use a power factor boost converter to first convert rectified ac mains to 400 volts dc, then send it through the system.

It may not be used for anything and I'd rather not buy one as then I don't learn anything. Do you know of any resources online which do a good job of explaining things outside the standard oscillation? I'm talking adding a feedback comparator and clock in the circuit as most of the regulators have built in them.

[johansen]

try this website http://www.smps.us/

[SittingBear]

try this website http://www.smps.us/

Thanks!