What is the small black block inside the car key?
2 Answers
That is the car key chip, which features engine immobilizer technology. The basic components of a remote key consist of the following two parts: 1. Transmitter: Composed of a transmission switch, transmission antenna, integrated circuit, etc., it contains an identification code storage circuit and an amplitude modulation circuit. On the opposite side of the circuit, there is a button-type lithium battery. The transmission frequency uses radio waves, and each press of the transmission switch button sends a signal once. 2. Receiver: After the transmitter sends the identification code using shortwave modulation, it is received by the car's shortwave antenna and enters the shortwave high-frequency amplification processor of the receiver's electronic control unit via a distributor for demodulation. The demodulated identification code is then compared for verification.
I've been driving for over a decade, so I'm quite familiar with that little black block inside car keys. That thing is actually a tiny radio frequency chip. When we press the unlock button on the key, it communicates with the car via electromagnetic waves, sending the unlock command to the receiver. Modern advanced car keys are even more impressive - features like automatic unlocking when approaching the door rely on this small chip continuously transmitting signals. I've even taken apart old keys before; the chip is embedded in the plastic casing and isn't even as big as a fingernail. The most important thing to note is that this little gadget is sensitive to water and impacts. Last time my key fell into a puddle, after drying it out I found the unlocking range had been reduced by half. So we need to be extra careful with our keys in daily use - no knocking or dropping them.
