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SK207 Heterodyne Detector |
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Schematic Diagram
*Eagle is a layout editor from CADSoft, a freeware version is available (Win & Lin)
Parts List
component description/value ------------------------------- SG1 Ultrasound transducer (receiver), 40 khz SPK1 Audio speaker IC1 CD4069 Hex inverter IC2 LM386 Audio amplifier D1, D2 1N4148 High speed small signal diodes R1 1 k-ohm Resistor 1/4 Watt, 5% R2, R3, R5 1 M-ohm Resistor 1/4 Watt, 5% R4 100 k-ohm Resistor 1/4 Watt, 5% R6 470 ohm Resistor 1/4 Watt, 5% R7, R8 470 k-ohm Resistor 1/4 Watt, 5% R9 10 k-ohm Resistor 1/4 Watt, 5% R10 10 ohm Resistor 1/4 Watt, 5% VR1 0-10 k-ohm Variable resistor VR2 0-200 k-ohm Variable resistor C1, C2, C3, C7 0.01 uF Ceramic capacitor, 25V C4 20 pF Ceramic capacitor, 25V C5 220 uF Electrolytic capacitor, 16V C6, C13 0.04 uF Ceramic capacitor, 25V C8, C9 0.022 uF Mylar capacitor, 50V, +/- 10% C10, C11 100 pF Ceramic capacitor, 25V C12 100 uF Electrolytic capacitor, 16V C14 10 uF Electrolytic capacitor, 16V C15 47 uF Electrolytic capacitor, 16V
Ultrasound Receiver
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RadioShack ($4.95) no more?
Gibson Tech Ed ($3.19) A small 40 Khz ultrasound receiver (Velleman / MA40A5R). The bandwith of these piezo-transducers has a narrow peak around 40 khz. A group of students at UNN has measured it. |
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CD4069 hex inverter
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"The CD4069UB consists of six inverter circuits and is manufactured using
complementary MOS (CMOS) to achieve wide power supply operating range,
low power consumption, high noise immunity, and symmetric controlled rise
and fall times."
Fairchild CD4069UBC.
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LM386 audio amplifier
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"The LM386 is a power amplifier designed for use in low voltage consumer
applications. The gain is internally set to 20 to keep external part count low,
but the addition of an external resistor and capacitor between pins 1 and 8
will increase the gain to any value up to 200."
National LM386
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