Circuit diagram of using photoelectric coupler to make mobile phone call reminder

 An optocoupler is an electrical-to-optical-to-electrical conversion device that uses light as a medium to transmit electrical signals. It consists of two parts: a light source and a light receiver. The light source and the light receiver are assembled in the same sealed shell and separated from each other by transparent insulators. The pins of the light source are the input terminals, and the pins of the light receiver are the output terminals. Common light source sources are light-emitting diodes, and the light receivers are photodiodes, phototransistors, etc.

When driving a motorcycle, the ringing tone of the mobile phone is often not heard because the vehicle itself and the surrounding environment are noisy, which is very inconvenient. In order to solve this problem, the author designed a voice-type mobile phone call notification device for vehicles, which can be easily installed inside the motorcycle. It can work automatically without turning on the power switch or other operations when using it. Only when the motorcycle is running, if When the driver's cell phone rings, a loud voice prompt will sound, telling the driver: "Someone is calling your cell phone, please answer it!"

Circuit principle: The mobile phone call indicator is a novel mobile phone decoration. It is now sold in communication equipment stores or mobile phone specialty stores. The price is about 20 yuan. When it works, it intercepts the response of a specific frequency when the mobile phone rings. After the tone, the ultra-high-brightness light-emitting diode emits an eye-catching flash. When the indicator flashes, it does not target a specific mobile phone. Its effective range is about 1 meter, which means that as long as the mobile phone is ringing within 1 meter of the mobile phone's incoming call indicator , the indicator will flash. The indicators sold on the market are relatively small, about the size of a button, with a small spiral antenna. During production, the two leads of the ultra-high brightness light-emitting diode are led out and connected to the photoelectric coupler. When the incoming call indicator flashes, the photoelectric coupler will be turned on repeatedly. Since the conduction voltage of the light-emitting diode inside the optocoupler is lower than that of the ultra-high-brightness light-emitting diode, the ultra-high-brightness light-emitting diode will not emit light at this time. CX01 is a voice recording and playback module produced by Zhejiang Yile Electronic Equipment Company. The price is very low, only about 10 yuan. The recording and playback time is 10 seconds. The information will not be lost after power failure. The working current is about 25 mA, and the quiescent current is 1 micro An, the trigger mode is pulse trigger, that is, the module is triggered to work once only when the trigger terminal jumps from high level to low level. After the module completes the playback, it automatically enters the low-power waiting state. The CX01 module is already equipped with a recording button, a playback button, a microphone, and a recording indicator light. When using it, you only need to connect an external 4.5 to 6.5 volt DC power supply and an 8 to 16 ohm speaker to record and play back the sound. Recording is performed first during production. After connecting the power and speakers, press and hold the recording button. At this time, the recording indicator light will light up. Record at a distance of 20 cm from the microphone: "Someone is calling your mobile phone, please answer!" After the recording is completed, just press the play button and the module will Play the voice prompt "Someone calls your mobile phone, please answer!". The volume of the beep directly emitted by the module is relatively low and may not be heard when installed on a motorcycle, so an audio power amplifier composed of LM386 is added. Connect one of the two speaker outputs of the module to the potentiometer W through the capacitor C1. Note that the two speaker outputs of the module cannot be directly connected to ground, otherwise the module will be permanently damaged! The volume of the prompt tone can be changed by adjusting the potentiometer. , the speaker can use the 8 ohm 1 watt oval speaker on the TV.

The power supply of this device can be connected to the ignition switch of the motorcycle. When the motorcycle is running, it can obtain a 12-volt DC voltage and obtain a 6-volt working power supply after being stabilized and filtered by LM7806. When installing, please note that the antenna of the mobile phone call indicator cannot be close to the metal parts of the motorcycle. It is best to be as close as possible to your mobile phone to ensure reliable operation. When someone calls your cell phone while driving, it will repeatedly remind you to answer the phone with voice. When you turn off the motorcycle and answer the phone, the device will automatically stop reminding you. It's best to keep it as close to your phone as possible to ensure reliable work. When someone calls your cell phone while driving, it will repeatedly remind you to answer the phone with voice. When you turn off the motorcycle and answer the phone, the device will automatically stop reminding you.