The use of the sampling circuit is actually a closed-loop control process of the circuit, which can also be understood as a negative feedback process. The collected signal is sent to the main control chip for adjustment. Today, the technical staff of CITIC Hua will introduce the three components of the sampling circuit to you! Let's take a look!

The sampling here is actually divided into current sampling, voltage sampling, DC sampling and AC sampling. The sampling type is determined by the load, and the sampling can be divided into high-voltage side sampling and low-voltage side sampling.

Let's take a look at this common circuit: This circuit is a synchronous signal generation circuit, which is often used in grid voltage sampling circuits.

The circuit consists of three parts:

1. Resistor, sliding line rheostat and voltage comparator LF353 form a buffer link.

2. The voltage comparator LF353 performs zero-cross comparison.

3. The output part of the circuit, that is, the input circuit of the I/O port of the single chip system clamp protection.