Heart rate detection circuit diagrams

A cadmium sulfide photoresistor (CD1) fingertip can be detected through the filter. CD1 forms part of the sense amplifier feedback network. A section of the sense amplifier (ICA) produces weak signals that may be further amplified by ICB. These signals are often used with a user-adjustable threshold for comparison, where comparator ICD triggers the piezoelectric buzzer (PZ1) when the switch is activated.

The circuit utilizes a cadmium sulfide (CdS) photoresistor, which is sensitive to light and changes its resistance based on the intensity of incident light. The photoresistor (CD1) is integrated into a feedback network that is part of a sense amplifier (ICA). This configuration allows for the detection of light levels and generates an output signal that reflects the ambient light conditions.

The weak signals produced by the sense amplifier (ICA) are routed to an additional amplification stage (ICB) to ensure that the signal strength is sufficient for further processing. This amplification is crucial for enhancing the signal-to-noise ratio, allowing for more accurate detection of light changes.

A user-adjustable threshold is implemented in the circuit, enabling users to set a specific light level that will trigger subsequent actions. This threshold is compared against the amplified signals using a comparator (ICD). When the light level exceeds the set threshold, the comparator activates, which in turn triggers a piezoelectric buzzer (PZ1). The buzzer serves as an alert mechanism, providing auditory feedback when the light intensity reaches the predefined level.

The entire circuit is designed to operate efficiently with minimal power consumption while providing reliable performance in detecting light changes. The inclusion of user-adjustable settings enhances the versatility of the application, allowing it to be tailored for various environments and requirements. Overall, the integration of the CdS photoresistor, sense amplifier, and comparator in this circuit demonstrates a practical approach to light sensing and alerting mechanisms in electronic applications. Cadmium sulfide photoresistor CD1 fingertip can be detected through the filter, CD1 form the sense amplifier feedback network, a part of the sense amplifier ICA produces weak s ignals, these signals may be further amplified ICB. These signals are often used and user-adjustable threshold for comparison, comparator ICD trigger piezoelectric buzzer PZ1 the switch.