Saturday, March 10, 2012
This video shows a DC to AC power inverter that has a regulatet output voltage, and there is no intergrated circuit used. The 50Hz square wave signal gets generated by a 2 transistor oscillator. The 50hz square wave signal then gets amplified with driver transistors, which "drive" the fullbridge that consists 2 TIP122 and 2 TIP127 darlington transistors. So this fullbridge switches the transformer to the power supply and changes it´s polarity - that results AC and this AC is beeing amplified by the transformer. The voltage regulation system consists mainly a voltage divider and a transistor that is "pre biased" and then gets negative voltage from the voltage divider. The NPN transistor then amplifies the difference from these voltages and leads it to the TIP127 PNP transistor which is mainly reliable for the power that gets fed into the transformer. This power inverter does not have that good efficiency. The transistors get pretty hot after some minutes of running the CD radio that I showed. Also the input voltage must be at least 6V higher than the transformer voltage...With a 18V transformer, and 24V input to the power inverter I was able to power a 230V 40W bulb at it´s normal brightness, but the bulb was "flickering" so I don´t know if that came from the power supply or the inverter. This project is rather some kind of "proof of concept" project that I made, but I will share the circuit diagramm soon so you can re built the inverter if you want. The frequency is ...
http://www.youtube.com/watch?v=D2fBIPZomuc&hl=en
Labels: Inverter, Transistor