Here is a quick test of a russian СГ2С (SG2S) 75V voltage valve regulator:
The CCS is a classic cascoded DN2540 MOSFET. A russian PIO capacitor is bypassing the regulator and the input impedance is the Pete Millet’s interface impedance. HT is a well regulated variable power supply.
When near maximum bias current is achieved (circa 30mA), the noise floor is surprisingly low: -85.5dB / 53uV.
Need to capture input of power supply at the CCS input 🙂
Edit: after measuring the power supply noise level and finding that is near -90dB, came up to the conclusion that the above noise level is the VR noise. Quite good for a simple (but effective) voltage regulator. Gary Pimms used this configuration many times on his designs…
Update
Upon request from Vyacheslav, here is the noise analysis for different current points:
As you can see it’s very linear. There is a 4dB difference between 5mA and 40mA.
Also tested ripple attenuation using a poor-regulated HT power supply. Here are the interesting results:
- 62dB @50Hz
- 80dB @100Hz
Hi Alejandro,
very interesting analysis СГ2С!
ripple -85.5dB / 53uV – if the current is 30 mA,
but what level ripple – if 5mA, 10mA, 20mA, and 40mA (when the maximum current)? you have the measurements?
I want to know when (level current) minimum ripple noise?
P.S. they also have nice illuminated 🙂
Vyacheslav.
Ukraine, Dnepropetrovsk
Hi Vyacheslav,
No, I don’t have. Did a quick test, so will try to measure noise level at different currents.
Cheers,
Ale
Hi Vyacheslav,
Had to rerun the tests, see updated post 🙂
Cheers,
Ale
Ooo, the linear response!
Alejandro. Many thanks!
Photo – looks very good 🙂 balloons glow (neon-argon mixture) 🙂
Yes, a good stabilitron (VR) – and the price is low … for example, in Ukraine (in Dnepropetrovsk, the radio market), only 0.5$ 🙂
Vyacheslav, Ukraine, Dnepropetrovsk
Hope this helps! Will drop you an email, is the email you registered a valid one?
Thanks
Ale
I already answered you
thank you
Vyacheslav