See upper side of the figure! It is called the pure-complementally-push-pull-amplifier. I made it and the maximum power of it was 110mW. See lower side of figure.
New type of complimentary power amplifier (It is my idea!)
I will show you my new idea about a complimentary power amplifier. See the circuit of upside “ef0k”! This circuit has a weak point. The current of the bias diodes changes, because the voltage on the output of the driver IC changes. Then the bias voltage has to changes. That makes a distortion. See the circuit of lower side “ef3”! IC2 and TR1 construct an emitter follower circuit like that of “ef1”. IC3 and TR2 also construct an emitter follower. On each circuit, the minus input of the operational amplifier is connected to the emitter of the transistor; therefore the emitter’s voltage becomes the same voltage from a plus input of the operational amplifier. Therefore this circuit constructs a linear current amplifier. The voltage amplification of it is 1 times. IC1 works as a voltage amplifier. The minus input of it is connected to the output of the whole circuit. Therefore the whole minus feedback is made by IC1. The distortion of this circuit is very small. This amplifier has 0.9W power output. Frequency characteristic is very flat from 333Hz to 24 kHz. It is my idea. But I am only amateur of electronics. I did not make any survey about patent of this circuit.
I would like for you to put my mail on your home page. I am attaching the amplifier schematic in gif format this time in hopes that you can read it. Again, thanks for putting up such a great page. Best Regards, Ray Given AB0Hz —–Original Message—– From: firstname.lastname@example.org [SMTP:email@example.com] Sent: Saturday, December 11, 1999 6:39 AM To: ‘Ray Given’ Subject: RE: Dear Ray. Thanks your letter. I want to up your mail on my home page. Please agree it. Please send me what you send me with gif or bmp! I can not deal tiff. Kaz ———- From: Ray Given[SMTP:firstname.lastname@example.org] Sent: Saturday, December 11, 1999 5:39 To: ‘email@example.com’<< (J L'2Y : Aud_AMP.tiff>>Dear Kazuhiro, (J I want to thank you for putting up such a wonderful web site. I am a radio amateur and enjoy building equipment myself. I have spent many wonderful hours looking at your designs and contemplating my own. I particularly want to thank you for the idea on building an audio amplifier using a Quad Op Amp and two power transistors. I am attaching a schematic of my finished amplifier. It will drive a 4 ohm/15watt computer speaker at 2.5 watts and sounds great. It works extremely well and will be a standard building block for my future projects needing an audio amplifier. It also provides one extra Op Amp to do additional filtering if necessary. The minor circuit changes insured stable operation with out oscillation. I have attached a copy of the schematic in tif format. 73 Ray Given AB0Hz.
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