Hello I am looking for some assistance/suggestions how to improve this circuit.
It is a LM2576 simple switcher (3.3V), wired to external p-ch MOSFET + diode/coil configured for buck converter.
Gate drive is done with a small transformer, which on the input side has 47 Ohms dampin resistor. Turns are about 3:1
It works so far, having seperate supplies for LM2576/buck input voltage.
This voltage I can drive higher than 50V, using a dc/dc module, wired to 12V electronic transformer. Another transformer same model is also used for the LM2576 supply.
There is no input capacitor, only a large ferrite coil.
Which will emit noises, if I increase the input voltage, and also output voltage.
At lower output voltages, it remains quiet.
One improvement was already made, adding a reset loop to the gate drive transformer.
Any advice how to improve the gate drive/the circuit?
The transformer likely will emit spikes upto 100V, I tested that in LTSpice.
Adding the reset loop, noise in the filter coil (not seen in the photo) is greatly reduced.
Are there additional circuits that I can add to the transformer drive?
Any good websites?
The proto circuit is built that way in order to make changes as required, without too much effort. Isn't the way I build circuits in general.
It is a LM2576 simple switcher (3.3V), wired to external p-ch MOSFET + diode/coil configured for buck converter.
Gate drive is done with a small transformer, which on the input side has 47 Ohms dampin resistor. Turns are about 3:1
It works so far, having seperate supplies for LM2576/buck input voltage.
This voltage I can drive higher than 50V, using a dc/dc module, wired to 12V electronic transformer. Another transformer same model is also used for the LM2576 supply.
There is no input capacitor, only a large ferrite coil.
Which will emit noises, if I increase the input voltage, and also output voltage.
At lower output voltages, it remains quiet.
One improvement was already made, adding a reset loop to the gate drive transformer.
Any advice how to improve the gate drive/the circuit?
The transformer likely will emit spikes upto 100V, I tested that in LTSpice.
Adding the reset loop, noise in the filter coil (not seen in the photo) is greatly reduced.
Are there additional circuits that I can add to the transformer drive?
Any good websites?
The proto circuit is built that way in order to make changes as required, without too much effort. Isn't the way I build circuits in general.
Attachments
-
150.8 KB Views: 226