This circuit uses four BJTs – 3 NPN and 1 PNP high current to drive the load. It has two touch pads, one for On and one for Off. I don’t see any information about the power supply voltage or load current. Some maximum voltage and current should be given for the circuit as shown.
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Uses a 12 key keyboard and texts like an old Nokia phone with multiple keypresses. http://www.technoblogy.com/show?2AON&fbclid=IwQ0xDSwL88ShjbGNrAvzr1WV4dG4DYWVtAjExAAEeX19OxuYe1QO8mrox71F6Zl_KCUppukTfJn3iSrHyEVT51xLwOmz2jhPHLKY_aem_is4HJCST113TNXDXWaTXGw
This short uses a CD4026, a 7 segment display, 9V battery, some resistors, an IR LED and a CdS photocell or phototransistor. Break the IR beam and the display advances to the next digit. https://www.facebook.com/reel/525596709839365?mibextid=9drbnH
This is an AM transmitter that this guy built. He says it’s rich in harmonics – it has no tuning nor low pass filtering and the stages are class C, no forward bias. It should have all the things used to minimize harmonics, like a low pass filter. Class C operation is used to maximize
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This messy bunch of parts is a 0 to 9V adjustable power supply. The original power supply board connected the two transistors in the Darlington Configuration. The unregulated 12V input goes through a 187 ohm resistor to a 10V zener diode to give a stable reference voltage. This voltage is fed to a 2.5k linear
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This 2.5 min video uses a SS8050 transistor which is not very good for a 100 MHz oscillator. https://www.facebook.com/reel/347155875050146?mibextid=9drbnH&s=yWDuG2&fs=e
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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A basic one transistor regen receiver uses an MPF102 JFET to give the regenerative gain. Also uses two transistors to amplify the audio to drive an earphone. https://www.circuitbasics.com/what-are-fm-receivers/
This is a long article but a very interesting project. It uses HSMS-2850 Schottky detector diodes in a discriminator. He uses WE 1200 ohm sound powered headphones. He’s Canadian. https://electronbunker.ca/eb/FMCrystalSet.html
This seems to be pretty much all of the kits. http://my.core.com/~sparktron/pbox.html
