The circuit diagram reveals several critical protection layers: Overload Protection:
: Offers several detailed documents including the Homage UPS Schematic Overview and a general 1000VA UPS Circuit Diagram Guide .
The 12V DC input is switched at high frequencies through an array of power MOSFETs (commonly IRF3205, IRFB7430, or similar high-current components) into a compact, high-frequency ferrite transformer. Homage Ups Circuit Diagram 1000va Pdf
When mains power fails, the microcontroller senses this and immediately switches the input relay to disconnect from the main supply. The circuit then pulls energy from the 12V battery, which is inverted by the MOSFETs and boosted by the transformer to provide output. C. Overload Protection
Faulty charging SCRs or open-circuit sensing resistors. The circuit then pulls energy from the 12V
High-quality electromagnetic relays (usually rated at 12V coil, 16A/30A contacts).
: The inverter stage MOSFETs often short-circuit under heavy load. Relay Chattering Homage Ups Circuit Diagram 1000va Pdf
+---------------+ | AC Input | +---------------+ | | v +---------------+ | Rectifier | | (Diode Bridge) | +---------------+ | | v +---------------+ | Capacitor | | (220uF/250V) | +---------------+ | | v +---------------+ | Inverter | | (TL494 or | | SG3525) | +---------------+ | | v +---------------+ | Power MOSFETs | | (2 x IRF3205) | +---------------+ | | v +---------------+ | Transformer | | (1000VA, 220V/230V) | +---------------+ | | v +---------------+ | AC Output | +---------------+
Consists of four high-voltage MOSFETs or IGBTs configured in an "H" shape (H-Bridge).