Search results
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Power source for smoke detector
Hee, hee. I am going to keep away from you because you exhale deadly(??) CO2 carbon dioxide. I use CO detectors because carbon monoxide is deadly.- Audioguru
- Post #10
- Forum: LEDs and Optoelectronics
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Replace variable capacitor with varicap
What is difficult about a varicap? You simply apply a reverse bias voltage and the amount of voltage determines its capacitance. What is difficult about a simple LC tuned circuit? They resonate at their calculated frequency. You probably hear the noise made by the transistors that have nothing...- Audioguru
- Post #16
- Forum: Radio and Wireless
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Design bass amplifier
On the internet there are many tutorials for designing filters but I simply copied the subwoofer filter from an audio site like Elliot Sound Products. There is a Japanese site that calculates parts values for your filter but the schematic of the filter looks like mine and not like yours. -
Acceptable Zener regulator tolerances
The amplifier circuit has lots and lots of negative feedback so that a change of the zener diode voltage will barely change the output voltage.- Audioguru
- Post #13
- Forum: Power Electronics
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Replace variable capacitor with varicap
The circuit is missing an AM detector diode and is also missing an audio power amplifier. The transistors simply amplify and are probably overloaded by the radio frequency of an AM station.- Audioguru
- Post #12
- Forum: Radio and Wireless
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Design bass amplifier
It looks like you are picking parts randomly instead of designing a 3rd order lowpass filter. Here is yours and here is mine: -
Design bass amplifier
A TL08x is a general purpose opamp with a Jfet input for very high input resistance. It produces frequencies up to 100kHz very well. But a TL07x is for audio because it is a TL08x selected for low noise (a TL08x is probably noisy because all the low noise ones are sold as a TL07x. They have a... -
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Design bass amplifier
Didn't you know that a lousy old LM358 is terrible for audio? 1) It produces horrible crossover distortion. 2) It is noisy (lots of hissss). 3) It has trouble producing high levels above only 2kHz. Use a modern opamp designed for audio instead. An OPA134 single, OPA2134 dual and OPA4134 quad... -
Photo sensor
Why does the opamp U1 have no part number? The text on your schematic is very fuzzy and hard to read.- Audioguru
- Post #2
- Forum: Electronics Homework Help
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How do I make my own musical instrument?
You should also look in Google for "e-drum circuit" and maybe you can make a percussion instrument to be played world-wide.- Audioguru
- Post #12
- Forum: General Electronics Discussion
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Design bass amplifier
Bose calls their dinky little 4" woofer a sub-woofer. It does not produce sounds below 100Hz so it ain't a sub-woofer. I have a pretty good sounding Sylvania 2.1 sound system in my TV/computer room that cost $25.00 CAN on sale. It has two satellite mid/high speakers each with two 1.5" long... -
Design bass amplifier
Jose says "the bass seems to influence the offset" so I think the bass is one polarity pulses that offsets the output until the input and output capacitors charge or discharge to the average voltages of the one-sided pulses. It doesn't matter unless the levels are so high that the output clips... -
Design bass amplifier
Only people who play acid rock have the amplifiers clipping like crazy, but it happens often so the speakers should be sturdy enough to handle lots of power. He has "a room" (a bedroom?) and he decided that a TDA2003 amplifier for each tweeter and a TDA2030 for the woofer will be loud enough... -
Design bass amplifier
Speakers always have a higher power rating than the amplifier so the speakers do not blow up when the music plays loudly. Your tweeters need a highpass filter because low frequencies will damage them. Your woofer needs a stereo to mono converter (2 resistors) and a lowpass filter because a... -
Design bass amplifier
I can't remember their name but I looked on a map and they are gone. -
Design bass amplifier
I bought some inductors from a local high-end speaker manufacturer. My finished speakers did not sound good so I measured their very poor response and discovered the wrong inductance marked on the inductor. I went back to the speaker manufacturer and complained that their marked inductance was... -
Airplane transmitters/receiver
Airplane communications use AM that is full of static and interference so that a pilot in trouble can break in. If FM was used then a pilot in trouble will be blocked by FM's "capture ratio". Communications use VHF from 118MHz to 137MHz, not microwaves. I do not think a technician repairs a...- Audioguru
- Post #2
- Forum: General Electronics Discussion
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Design bass amplifier
If you use one amplifier to drive a woofer and a tweeter then you need a "passive crossover network circuit", look in Google for a website that has them. A first order filter has gradual slopes and the low frequencies might blow up the tweeter and let the woofer shriek high frequencies. A... -
Clarification of terms S:N
A pot that makes crackly sounds when you turn it has DC on it (caused by a leaky coupling capacitor) or it is dirty. Hum or buzzing is not "noise", it is interference caused by improper wiring. Noise is "hiss" caused by electronic parts with poor spec's.