TS5813 VTX - internal voltage regulator

[dmr123]

Hello All,
I was looking recently for a cheap VTX for my drone and came across TX5813 (25mW 40ch) from ebay.
I googled quite a lot on this VTX and on it's bigger brother TS5823 reading on issues and mods. Both seems to share exactly the same core module.

Both VTXs state that Operating Voltage is 7V-24V. On the other side there are people who claim both modules need just 3.3V (5v in some cases).
if you take standard 3S LiPo as a power source, you will have 12.6V-3.3V=9.3V to dissipate as heat! A lot!

So, I wonder, is there anyone tried to bypass/disable internal voltage regulator of TS5813/TS5823 and source this with just 3.3V (or at least 1S LiPo).

I would appreciate any tips on this.

Thanks.

[iwan_canobi]

These units use switching regulators to drop the supply voltage down, these are typically very efficient and don't really generate too much heat since they just vary the duty cycle to reduce the voltage.

What you have described is how a linear regulator works, which is why they need big heatsinks as they just lose the extra energy via heat mostly.

So if it's just to save waste heat then I wouldn't bother, unless you have another reason to want to try and bypass it? Switching regulators are typically noisier but there are bigger sources of noise to worry about before this.