Functions of intelligent sphygmomanometer:
The victims of high-frequency diseases such as hypertension are mainly concentrated in the elderly population over 50 years old. However, most of these people are faced with the problem of not seeing the manual and being unable to operate when using traditional blood pressure timers, which makes them inconvenient in use. However, the intelligent sphygmomanometer equipped with NVC series voice chip can have voice function and voice playback function, so that the measurement results of the sphygmomanometer can be clearly heard before, during and after the measurement, which is very convenient for the elderly and the poor.
The characteristics and advantages of voice chips:
Features and advantages:
Working voltage: 2V~5.2V;
In standby mode, the static current is less than 5uA
Accurate/-1% internal oscillation, low voltage reset (LVR=1.8V) watchdog timing, I/O reset function
PWM pure audio output, capable of directly driving 8 Ω/0.5W horns and buzzers, DAC audio output, and external power amplifier
Control mode with serial port: 1-wire serial port, 2-wire serial port, supporting BUSY status output function
Voice chip prompt tone:The sphygmomanometer is equipped with voice prompt. In addition to simple fault prompts, it can also serve as a promotional tool for merchants. For example, the startup language can be "XXX intelligent sphygmomanometer wishes you a happy life", etc. In addition, there are some voice prompts in the measurement process of the sphygmomanometer, so that the elderly can get good guidance in the measurement process.
Circuit operation precautions:
Many places generate static electricity. The following protective measures can effectively prevent damage to MOS circuits due to electrostatic discharge.
Operators must be grounded through an anti-static wrist strap.
The equipment casing must be grounded.
The tools used during the assembly process must be grounded.
Common precautions for voice chips:
The standard speaker for voice chips is 8 ohms, 0.25 to 0.5 watts. Ohm value range: 8-32 ohms, the higher the value, the softer the volume. The power range in Europe is 0.25 to 1 watt (W). Unable to drive 4 ohm speakers and speakers above 2W.
The 104 capacitors (0.1uF) of the positive and negative poles in the voice chip circuit, when the button cell is below 4.5V, can not be omitted except for some simple function chips, otherwise it will cause silence, voice interruption, noise and other undesirable conditions.
When designing a circuit board with capacitors, the closer it is to the chip, the better!
Except for the simple functional chips specified, the positive and negative 104 capacitors must not be left!
When there are transformers, motors, and large inductance components in the application circuit, the voice chip should comply with electromagnetic specifications and take corresponding preventive measures. A voice chip is a sensitive device.