I'm trying to build a small inexpensive converter 12VDC to 24 VDC @ 1.5 to 2.0 Amps.
The MC33063A looks like a good option, but I'll appreciate any ideas and comments.
NSM

 

I'm trying to build a small inexpensive converter 12VDC to 24 VDC @ 1.5 to 2.0 Amps.
The MC33063A looks like a good option, but I'll appreciate any ideas and comments.
NSM

There are various online and downloadable calculators that work out the component & inductor values, but 1.5A is about the limit for a 34063 unless you use an external transistor to boost it.

 

Thanks' Ian,
I'm looking for these calculators, but I didn't had much luck so far.
Anyway, I retested my 24Volt users, and they peak at 850mA, so I don't need to add any components to the 33063.
Wish me luck.
Regards,
NSM

 

Thanks' Ian,
I'm looking for these calculators, but I didn't had much luck so far.
Anyway, I retested my 24Volt users, and they peak at 850mA, so I don't need to add any components to the 33063.
Wish me luck.
Regards,
NSM

First hit:

http://dics.voicecontrol.ro/tutorials/mc34063/

http://www.nomad.ee/micros/mc34063a/

http://ehc.ac/projects/mc34063uc/files/1.1.0/

 

Thanks' Ian,
I'm looking for these calculators, but I didn't had much luck so far.
Anyway, I retested my 24Volt users, and they peak at 850mA, so I don't need to add any components to the 33063.
...

You probably still do.

A 34063 in boost 12v->24v will run about 75% efficiency at best. So to get 24v 0.85A output requires 12v 2.26A input.

You need a switching device good for 2.26A average at least. Probably a device with a low ON resistance at 5A would be best.

 

You probably still do.

A 34063 in boost 12v->24v will run about 75% efficiency at best. So to get 24v 0.85A output requires 12v 2.26A input.

You need a switching device good for 2.26A average at least. Probably a device with a low ON resistance at 5A would be best.

IIRC, there's some more info in the 78S40 appnote from Motorola/On-Semi. Its basically the same regulator with a few extra bits in the package.