Transformerless inverter using SG 35xx

ATIKU

Newbie level 4
Joined
Feb 28, 2024
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Visit site
Activity points
43
Pls I need your help

1.Pls help me check the transformerless inverter circuit using SG 35xx will it really works in real practical

2. One of my mentors said it will work but by changing the bootstrap input to 12v and when I change it to 12v my AC output is around 82v instead of 230v AC

Pls help am confused
 
Last edited by a moderator:

Sort by date Sort by votes
Located in the schematic is an H-bridge, made from bjt's or mosfets or both. Its power source is 300 V via batter ies. It's unclear what bias voltage turns those components On & Off. To accomplish that purpose bias needs to be at the correct level during one-half of the cycle, and correct level during the other half. All but one appear to be N-devices. N-devices require a different biasing schedule than P-devices. At certain positions in your schematic, a P-device may be a suitable choice rather than an N-device. I could be wrong.
 
Upvote 0 Downvote
There are several issues with the circuit. Obvious point is that Q1 and Q2 are shorting UC1525 outputs and respectively low side gate voltage. Using 300 V DC bus as bootstrap supply will immediately destroy transistors in a real circuit. High side gate drivers must have high voltage rating, presently used MPSH10 are low voltage RF transistors. Why not using bootstrap driver IC?

I would also suggest to draw the circuit in a regular H-bridge form, I guess many readers don't even recognize high- and low-side transistors.
 

Upvote 0 Downvote
Hmmmm ,I don't understand

Pls Is it a AI comment or recommend because the information looks like a computer language
--- Updated ---

Pl
Thanks

But I don't get the short circuit points
 

Upvote 0 Downvote
ATIKU said:
But I don't get the short circuit points
Click to expand...
Bipolar transistor Vbe is,on is about 0.7 V. UC3525A output is clamped to this voltage, low side transistors are never turned on.
--- Updated ---

As 3525 outputs can source upto 500 mA without safe current limiting, 3525 and driver transistors will be most likely destroyed.
 

Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…