H-Bridge as Quasi Class AB Audio Amp ???

Question

Has anyone come across a good discussion or schematic relative to using an h-bridge as a sort of class AB audio amplifier ?

Think of a motor as kind of a really bad sub-sub-woofer and ...

Splitting the input through an inverting and non-inverting op amp ... and biasing the transistor pairs to borderline conductance .... seems like it ought to go.

Not quite true AB quality, but good enough for a PA system or to drive sub-woofs perhaps. Low parts count and ability to use cheapo NPNs sans big transformers or caps would be plusses.

You see, I've got a ton of 3055s just sitting ... :-)

I've tried Googling ... but the necessary keywords bring up just too much junk, even after selecting-out "class d".

Jim Thompson · Accepted Answer

I have made "bridged" linear amplifiers for various of my vehicles toget reasonable power... I can really light up a 280ZX ;-)		                                        ...Jim Thompson-- | James E.Thompson, CTO                            |    mens     || Analog Innovations, Inc.                         |     et      || Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    || Phoenix, Arizona  85048    Skype: Contacts Only  |             || Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  || E-mail Icon at  |    1962     |                                 Help save the environment!             Please dispose of socialism responsibly!

whit3rd · Answer

TDA7294 is a pretty typical H-bridge amplifier for audio use. Unless you really want HIGH power, ICs are good enough (and accurate biasing of bipolar output stages is a dark art anyhow).

All-2n3055 amplifier final stages are more work than complementary pair amplifiers.

H-Bridge as Quasi Class AB Audio Amp ???

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