So this circuit changes 12V DC power from a battery into 115V AC power at 60Hz, 230V 50Hz, depending on the transformer secondary specifications. It can drive small AC electrical items up to 100 watts total power. It uses two UJT transistors to make the 60Hz timing speed and two power SCRs or transistors to […]
Inverter Circuits
90V to 400V Low Voltage Cutoff Circuit for Solar Inverters
Today we are going to discuss a purely analog high voltage protection circuit which is specially designed for solar power systems working with PV voltages from around 90 volts up to 400 volts DC. The main purpose of this circuit is to disconnect the inverter whenever the solar panel voltage falls below a safe level, […]
How to Add Adjustable Current and Voltage feedback Control to SG3525 High Power Inverters
If you want to build a very heavy power inverter or when you want to make a high frequency induction heater, or when you want to make a lab grade variable SMPS, then getting precise control over both output voltage and current is a major engineering hurdle. Most standard designs using the classic SG3525 PWM […]
Parallel MOSFET Calculator Tool: How to Connect MOSFETs in Parallel Safely
The following calculator tool can be used to correctly calculate all the parameters essential for connecting many number of MOSFETs in parallel. This ensures the current handling by the MOSFETs is implemented optimally, without any issues or technical errors, and keeps the MOSFETs safe for long term operations. MOSFET Parallel Calculator Total Load Current (Amps) […]
How to Upgrade EGS002 Inverter to 5kVA Level
In this article I will explain how to upgrade an EGS002 inverter board to 5kVA power level using the HCPL-3120 or HCPL-J312 opto isolated drivers with isolated inputs and isolated power supply stages. However, the low side MOSFETs are driven through ordinary BJT totem pole configuration such as by using BD139 and BD140 transistor pairs. […]
Simple H-Bridge Circuits Using BJTs and MOSFETs | No Need of Driver ICs
An H-bridge is one very useful circuit arrangement which lets us reverse the polarity across a load, so now with one DC supply we can make current flow through the load in both directions alternately. Because of that, these H-bridge circuits get used in many places like DC to AC inverter circuits, transformer drivers, bidirectional […]