1N5819s? Or just a couple of 1N4001s?

Started by Dave in sci.electronics.basics8 years ago 4 replies

I have been wanting to make use of a pair of 1N5819s to protect an RF amplifier I am building from static discharge, should someone touch the...

I have been wanting to make use of a pair of 1N5819s to protect an RF amplifier I am building from static discharge, should someone touch the antenna, but haven't been able to obtain any of these just yet. I DO have some 1N4001s however, and am honestly wondering what advantages the 1N5819s would have over the the more readily available 1N4001s (which are already sitting on my workbench....


distortion with Class B (with NFB) vs Class AB

Started by Anonymous in sci.electronics.basics8 years ago 45 replies

I was shocked to see such low distortion figures on this Class B audio amplifier: http://www.redcircuits.com/Page164.htm Is negative...

I was shocked to see such low distortion figures on this Class B audio amplifier: http://www.redcircuits.com/Page164.htm Is negative feedback sufficient to eliminate crossover distortion in Class B?


transistor

Started by gajendra singh in sci.electronics.basics10 years ago 5 replies

is transistor used as amplifier?

is transistor used as amplifier?


Critic of circuit before I build it.

Started by amdx in sci.electronics.basics7 years ago 21 replies

I'm about to build this circuit to compare output from different ferrite receive antennas. I will be using it with the the FET...

I'm about to build this circuit to compare output from different ferrite receive antennas. I will be using it with the the FET amplifier referenced at the bottom of the page, so the input impedance is not a concern. I'm mostly interested in the DC output to monitor signal levels. AM band frequencies. http://www.crystal-radio.eu/diodedetector/endiodedetector.htm Any fix for the si...


one transistor amplifier help

Started by amdx in sci.electronics.basics5 years ago 32 replies

I have the following amp. It originally had a 12V supply voltage, In an effort to get a larger swing on the output, I raised that to 24V. ...

I have the following amp. It originally had a 12V supply voltage, In an effort to get a larger swing on the output, I raised that to 24V. I now get 12.5Vpp on the output, I want to maximize the output signal. A gain of 3 will work for my circuit. What changes can I make to maximize the output swing. The input is at maximum before distortion is seen. > https://www.dropbox.com/s/07j


Designing The Perfect Coil?

Started by Ron Hubbard in sci.electronics.basics10 years ago 113 replies

I want to do an experiment in brainwave entrainment by making a 7 Hz sine wave oscillator out of an XR2206 frequency generator IC and a LM386...

I want to do an experiment in brainwave entrainment by making a 7 Hz sine wave oscillator out of an XR2206 frequency generator IC and a LM386 amplifier feeding a six inch diameter coil-- which should probably fit around my fat head. ;-) The LM386 has an 8 ohm output, so it shouldn't be hard to find a speaker, if I wanted to use one; but I don't know how to make a good 8 ohm coil to radia...


New Spice Model Posted

Started by Jim Thompson in sci.electronics.basics7 years ago

Just posted to the Device Models & Subcircuits page of my website... ApexMP118FD.zip Apex Microtechnology's...

Just posted to the Device Models & Subcircuits page of my website... ApexMP118FD.zip Apex Microtechnology's (www.apexanalog.com/) low quiescent, high power dissipation operational amplifier that integrates several new layers of onboard circuit protection including over current shut down. Onboard temperature monitoring circuitry, also new, enables the MP118FD to shut down...


For amdx: - Kleijer amplifier reworked.

Started by Fred Abse in sci.electronics.basics8 years ago 18 replies

Examination of a full model of the whole circuit revealed that the parallel input resistance would actually go negative somewhere around 1MHz,...

Examination of a full model of the whole circuit revealed that the parallel input resistance would actually go negative somewhere around 1MHz, exactly where dependent on source resistance. I got interested, and finished up doing a rework, addressing: Negative input resistance. Gain not unity, as claimed. Actually 4dB. Output operating point nowhere near Vcc/2, hence reduced output sw...


What's the point of a gain of 1 amp?

Started by Anonymous in sci.electronics.basics6 years ago 7 replies

I ordered the headphone amp from Oatley Electronics and it arrived yesterday. Reading the instructions and the explanation of how it works has...

I ordered the headphone amp from Oatley Electronics and it arrived yesterday. Reading the instructions and the explanation of how it works has me a little confused. Refer to this link: http://secure.oatleyelectronics.com/files/K272X.pdf The explanation says that there is a 7x gain output coming from the tubes. This output is next sent to the amplifier IC. The gain of this amp is set by two r...


Using mobile phone as an internet radio

Started by jim stone in sci.electronics.basics9 years ago 136 replies

Not being able to find a small internet radio to buy we liked, we got mobile phone with which we link with wi-fi to a modem router, and use it...

Not being able to find a small internet radio to buy we liked, we got mobile phone with which we link with wi-fi to a modem router, and use it as an internet radio. Keeping the phoned plugged into its charger all the time, we are using it to play *all-day* background classical music through an amplifier and speakers. Since the phone has no 'moving parts' unlike a computer, we are wonde...


Small signal RF amplifier ideas?

Started by Bill Bowden in sci.electronics.basics9 years ago 2 replies

Some ideas I hear about RF amps are to decouple each stage with a series resistor and a cap across the stage. The resistor is chosen to drop a...

Some ideas I hear about RF amps are to decouple each stage with a series resistor and a cap across the stage. The resistor is chosen to drop a small voltage and the cap to have a low reactance. Next, use a low noise device in the first stage and also separate the stages across the board to avoid positive feedback. Another trick is to align any tuned inductors at 90 degree angles to minimize f...


Op-amp voltage offset cancellation

Started by Patrick Chung in sci.electronics.basics7 years ago

Combination of one fast op-amp with large slew rate and large voltage offse= t with one op-amp with small slew rate and small voltage offset and...

Combination of one fast op-amp with large slew rate and large voltage offse= t with one op-amp with small slew rate and small voltage offset and low pas= s filter can be used for amplification input AC signal on high frequencies = without problem that amplifier can be saturated due to voltage offset prese= nce. Read more: http://www.cirvirlab.com/index.php/electronic/166-op-amp-current-o...


low-power audio amp basics

Started by Anonymous in sci.electronics.basics8 years ago 14 replies

For some low-power audio amps, usually less than 2 Watts, I see the amplifier powered by +V...

For some low-power audio amps, usually less than 2 Watts, I see the amplifier powered by +V and ground: http://www.redcircuits.com/Page33.htm For other, usually higher-powered amplifiers, I see a +/- power supply required. http://www.redcircuits.com/Page164.htm Do the amplifiers without a +/- supply continuously provide a voltage at 1/2 V during the silent parts, to allow the speaker room ...


JFET Hartley oscillator as a kind of L-C resonant circuit oscillator is practical L-C oscillator with JFET as active amplifier

Started by Patrick Chung in sci.electronics.basics8 years ago 1 reply

New tutorial is ready http://www.cirvirlab.com/index.php/tutorials/127-jfet-hartley-l-c-resonant-circuit-oscillator-si mulation.html ...

New tutorial is ready http://www.cirvirlab.com/index.php/tutorials/127-jfet-hartley-l-c-resonant-circuit-oscillator-si mulation.html It now can be simulated on: http://www.cirvirlab.com/simulation/jfet_hartley_oscillator_online.php


push-pull output simulation is ready

Started by Patrick Chung in sci.electronics.basics8 years ago 3 replies

Push-pull output is most popular output stage for op-amps and audio power amplifiers. New...

Push-pull output is most popular output stage for op-amps and audio power amplifiers. New tutorial: http://www.cirvirlab.com/index.php/tutorials/106-push-pull-output-push-pull-amplifier.html and simulation http://www.cirvirlab.com/simulation/push-pull_output_push_pull_amplifier_online.php are ready :-)


audio amplifier output transistors

Started by Anonymous in sci.electronics.basics13 years ago 8 replies

I noticed that TR7 is PNP and TR9 is NPN here: http://www.dself.dsl.pipex.com/ampins/dipa/dpafig1.gif Then over here, TR7 is NPN and TR9 is...

I noticed that TR7 is PNP and TR9 is NPN here: http://www.dself.dsl.pipex.com/ampins/dipa/dpafig1.gif Then over here, TR7 is NPN and TR9 is PNP: http://www.dself.dsl.pipex.com/ampins/dipa/dpafig33.gif Are these correct, or in error? Also - for building audio amps "on the cheap", would TIP41C/TIP42C do for output transistors in these schematics? Thanks, Michael