Components

The parts catalog. Wire, switches, resistors, capacitors, coils, transformers, and the relays and meters the operator wires into a circuit before the chips arrive.

Catalog

Symbol	Photo	Component
		Wire and cable. Copper conductor in PVC or rubber dielectric. Carries every signal and rail on the bench; a few inches at the right point reads anything that runs through.
		Switches. Mechanical break in a circuit. Push, toggle, slide, rotary, tilt (mercury switches in vibration bugs), or reed (magnetically actuated for concealment).
		Relays. A switch driven by an electromagnet. Logic-level coil commands a power-level contact; the basis of any electrically isolated kill switch.
		Moving coil meters. Analogue current and voltage display. Needle deflects with current through a coil in a permanent magnet; the dial face on every classic TSCM detector.
		Microphones. Sound to electrical. Carbon, dynamic, condenser, contact, or MEMS. The carbon mic was the spec for half a century of phone taps.
		Speakers. Electrical to sound. Voice coil in a magnetic gap drives a cone or dome; the piezo earpiece is the covert sibling.
		Gyro. Angular rate sensor. Reports rotation about each axis; MEMS variants are tiny and cheap.
		Accelerometer. Linear acceleration sensor. Detects gravity and motion; pair with a gyro for an IMU.
		GPS. Satellite positioning module. NMEA out, antenna in, fix in tens of seconds.
		IR. Infrared LED or photodiode. Emits or detects 850–950 nm light for remote control and proximity.
		EM. Electromagnetic field sensor. Magnetometer, Hall, or fluxgate; reports field strength and direction.
		mmWave. 24–77 GHz radar. Detects motion, presence, and velocity through plastic and clothing.
		Pressure. Pressure sensor. Barometric, gauge, or differential; piezoresistive or capacitive.
		Proximity. Non-contact detection. Inductive, capacitive, or optical; reports presence within range.
		Position. Position transducer. Potentiometer, encoder, LVDT, or resolver; absolute or incremental.
		Resistors. Two-terminal passive that opposes current flow. Bias networks, voltage dividers, current limiters; the cheap part that survives the operator’s mistakes.
		Capacitors. Two parallel plates separated by a dielectric. Stores charge; passes AC and blocks DC. A coupling cap lifts audio off a line tap without shorting the DC bias.
		Coils. Inductor. Stores energy in a magnetic field and resists changes in current. Pair one with a capacitor and you have the tuned tank of every superhet receiver.
		Transformers. Two coupled coils on a shared core. Steps voltage up or down by the turns ratio; the 600:600 telephone line transformer is the galvanic isolator behind every quiet wiretap.
		Batteries. Primary power for any standalone implant. Button cell to lithium primary; capacity sets the device’s listening time.
		Fuses. Sacrificial wire link. Opens when current exceeds the rating; protects expensive parts from cheap mistakes.
		Connectors. Physical interface. USB, RJ11, RJ45, coax, GPIO. Every implant either replaces a connector or rides on one.
		Solenoids. Coil that pulls a ferromagnetic plunger when energised. Doorbells, lock strikers, the hammer in a pick gun.
		Antennas. Conductor cut to a fraction of the wavelength. Every wireless bug, beacon, and SDR has one; cavity, dipole, whip, helical, or patch.
		Crystals. Quartz slab cut to a resonant frequency. Sets the carrier in transmitters and the clock in any micro.
		Piezo elements. Ceramic disc that flexes with voltage and generates voltage when flexed. Buzzers, contact mics, the tones in a blue or red box.

References

• Electricity for the underlying laws.

• Semiconductors for the active parts that consume these.