My younger brother has been building a small AC/DC inverter to run off a car battery when the power goes out (which happens rather frequently in these parts). Or rather, he's been trying. He started with this circuit, which didn't work well at all. I posted some queries about it here, and we got several quite useful replies from helpful forum members. Since it's no longer using a 555 (and I didn't see a way to rename the thread) I'm starting a new thread on the subject.
He's rebuilt the circuit, and is now using a PIC microcontroller to generate signals to drive a full H-bridge (rather than the 555-driven half bridge in the original circuit). The problem we're having is that, while the output of the bridge looks quite good with no load (see the first scope picture), as soon as the transformer is attached the waveform turns into a flat line with occasional spikes going here and there in a very unpromising fashion (see picture 2). Needless to say the output from the transformer is quite weak -- 16v RMS roughly.
I've attached a schematic of the circuit. If anyone has ideas about why the bridge output would go to pot when we hook up the transformer, or any other suggestions, we would be grateful indeed!
Thanks for your help,
Adam
He's rebuilt the circuit, and is now using a PIC microcontroller to generate signals to drive a full H-bridge (rather than the 555-driven half bridge in the original circuit). The problem we're having is that, while the output of the bridge looks quite good with no load (see the first scope picture), as soon as the transformer is attached the waveform turns into a flat line with occasional spikes going here and there in a very unpromising fashion (see picture 2). Needless to say the output from the transformer is quite weak -- 16v RMS roughly.
I've attached a schematic of the circuit. If anyone has ideas about why the bridge output would go to pot when we hook up the transformer, or any other suggestions, we would be grateful indeed!
Thanks for your help,
Adam
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