The modules use both the RCWL-9616 and the BISS-0001 but it seems the schematics are all labeled BISS-0001. The parts values are different. He gives some good information about them. They operate at 3.5 and 3.98 GHz – the ones I have were advertised at 5 GHz. Also he shows his own version that uses a
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I built this “tungsten roadwork beacon” as Clive calls it, using the parts given in my schematic (photo below). I didn’t have a 6V, 90 mA lamp, so I simulated it by using three 20 ohm, 1/4 Watt resistors in series, which gives 60 ohms and 100 mA load with 6VDC. For an indicator I
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Chuck commented about the audio oscillator being a BFO, and it reminded me that I’ve got an old RCA BFO audio oscillator stuck away in the garage. It was a cheap way of getting an audio sine wave that covered the full audio band without any switching. Nowadays it’s all done in sine and other
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He uses my SJT circuit in his web page. https://devopedia.org/joule-thief-circuit
From Talking Electronics. I’m not sure if this circuit can be frequency modulated the full amount for the FM broadcast band. It’s difficult to push a crystal off its resonant frequency. I’ll be trying it someday if I can find the right xtal. I would be more inclined to instead use a ceramic resonator. I
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Me and my high school friend made a DC to DC converter that would give us 30 or so volts at a couple amps from a 12 volt battery. We used germanium power transistors which could not go much above 10 kHz. The Delco’s and the 2N458A’s were our favorites – we managed to push
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MP3 Player To FM Radio Link (Mono) This circuit allows you to play your MP3 or any stereo audio source into a mono signal for reception on an FM radio. It has no antenna and has a range of a dozen or so meters. It operates off a 6 volt rechargeable Ni-MH battery pack but
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From FB post Apr 29 Joshua E. Hrouda I trained on Radar repair in the Army, and since then I’ve known that circuits with ‘lumped constants’ have problems with parasitic capacitance and inductance above a few hundred MHz. But I experimented with this circuit anyway. I think Colin should say, instead of ‘tight’, that the
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This is a low power oscillator using an air core coil and silver mica capacitors for stability. Parts values are subject to the frequency needed. There is no modulation. For FM the 10 pF capacitor would be lower and include a reverse biased diode as a varicap in parallel. The audio should be across this
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This is from Electronics Illustrated Projects 1968. It shows crystal sockets, but instead a RF coil may be used and its value will be about 220 microhenrys. And C1 and C2 will have to be changed to bring the frequency down to the AM band. The germanium transistors are no longer available so silicon transistors
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