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Tape Head Demagnetizer Cassette :
(electronic schematic / circuit added 2/05) |
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Telephone Headgear: A
compact, inexpensive and low component count telecom headset can be constructed using two readily available transistors and a few other electronic components. Since the circuit draws very little current, it is ideal for parallel operation with electronic Telephone set.
FAIR WARNING -THIS SITE HAS ANNOYING POP UP ADS. (added 4/02) |
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Telephone Headset Amplifier: This circuit goes between a telephone and a headset. The
project has a headset cord and plug (cut from a cheap cell phone headset) on the input and a suitable jack on the output. The speaker signal passes through this circuit, but the microphone signal is passed straight from the plug to the jack. This circuit is
specifically designed for ultra-low battery consumption. It uses a special control circuit (Q3, Q4 and Q5) to regulate the power amplifier’s quiescent current. Also, effort was spent to design an auto-on circuit (Q10 through Q14) that draws only 1.5 uA, yet has 15mV
sensitivity. Designed by Andrew R. Morris (added 09/05) |
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Telephone Record Control (randy): (circuit added 7/02) |
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Telephone Recorder (aaroncake): This circuit
lets you record your ph1-conversations automatically, notice that this circuit does not provide isolation between Telephone line and the recorder (added 4/02) |
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Telephone Recorder (tjacodesign):
This circuit automatically records all incoming and outgoing phone-conversations with an ordinary cassette or tape recorder. The circuit below distills the audio signal from the phone-line and automatically starts/stops the cassette recorder. (added 4/02) |
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Telephone Recording Circuit (epanorama):
How they work and some example (added 4/02) |
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Telephone Tap #1: Amplify or
record a telephone call with the simple circuit shown. The 8-W secondary winding of a miniature transistor output transformer is connected in series with either of the telephone lines. The1000-W primary winding can feed either a cassette recorder or an audio amplifier.
(added 2/03) |
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Terrestrial Set-Top Box (NTSC/PAL):
Intersil Application Block Diagram (app note added 6/06) |
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Theremin Controller: (electronic circuit added 4/05) |
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Theremin Model #145: (electronic
circuit added 7/03) |
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Three Level Audio Power Indicator: Battery-operated
Three LED display that connect it to loudspeaker output (added 9/04) |
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Tone Detector: (electronic circuit added
7/03) |
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Tone Generator: (electronic circuit added
7/03) |
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